ELECTRIC MACHINES

BACKGROUND

Technical Field

The present disclosure relates to a system designed to provide the benefits of multiple rotating electric machines within just one machine having the ability to reconfigure its coils in real time and under load.

Description Of The Related Art

For conventional drives and the associated rotating electric machines (motors and/or generators), these systems operate under a single speed torque characteristic along with a static efficiency curve. With both motors and generators, these limitations impact the capabilities of the application and often result in oversizing the machine, poor efficiency across a broad operating range, and thus wasted energy due to inefficient operations.

SUMMARY

A reconfigurable rotating electric machine having a rotor to rotate in association with a stator, at least one of the rotor and the stator having windings of one or more phases, may be summarized as including: a plurality of coils arranged to form the windings of one or more phases, each coil or group of coils of the plurality of coils having a pair of terminals to receive an electrical input; a plurality of switches arranged to connect each said coil or group of coils in series or parallel with another coil or group of coils of the plurality of coils to form a plurality of defined coil topology configurations; and a processor to control the plurality of switches, the processor having memory storing settings to determine a state of each of the plurality of switches for each of the defined coil topology configurations. The plurality of switches may be controllable to connect the plurality of coils into at least a first topology configuration and at least a second topology

configuration providing higher torque or higher speed than the at least first topology configuration. The plurality of switches may be controllable to connect the plurality of coils into at least a third topology configuration providing higher speed or higher torque than the at least first topology configuration. When the plurality of switches are controlled to connect the plurality of coils into the at least first topology configuration, each of the one or more phases may include two parallel sets of coils, each of the parallel sets of coils may include coils or groups of coils arranged in series, and the series-arranged coils or groups of coils of each of the parallel sets of coils may be positioned consecutively around a circumference of the stator. When the plurality of switches are controlled to connect the plurality of coils into the at least second topology configuration, each of the one or more phases may include two sets of coils or groups of coils arranged in series, and each of the sets of coils or groups of coils may be positioned consecutively around a circumference of the stator. When the plurality of switches are controlled to connect the plurality of coils into the third topology

configuration, each of the one or more phases may include two parallel sets of coils, each of the parallel sets of coils may include coils or groups of coils arranged in series, the series-arranged coils or groups of coils of each of the parallel sets of coils may include a first subgroup of coils or groups of coils positioned consecutively around a circumference of the stator and a second subgroup of coils or groups of coils positioned consecutively around a circumference of the stator, and the second subgroup of coils or groups of coils may be positioned at a location on the circumference of the stator spaced 90 degrees from a position of the first subgroup of coils or groups of coils on the circumference of the stator.

At least one of the rotor and the stator may have windings of at least a first phase and a second phase, and the plurality of switches may be controllable to connect the plurality of coils into at least a first force expansion topology configuration to form an electrical machine having two virtual poles, each of the at least first and the second phases may include an arrangement of coils positioned around a circumference of the stator, and at least a second force expansion topology configuration to form an electrical machine having more than two virtual poles. When the plurality of switches are controlled to connect the plurality of coils into the at least second force expansion topology configuration, the first phase may include one or more coils associated with the second phase in the first force expansion topology configuration. The plurality of switches may be controllable to connect the plurality of coils into at least a first force expansion topology configuration to form an electrical machine having two virtual poles and at least a second force expansion topology configuration to form an electrical machine having four virtual poles. The plurality of switches may be further controllable to connect the plurality of coils into at least a third force expansion topology

configuration to form an electrical machine having six virtual poles.

When the plurality of switches are controlled to connect the plurality of coils into the at least first force expansion topology configuration, each of the one or more phases may include an arrangement of coils, the arrangement of coils may include a first subgroup of coils positioned consecutively around a circumference of the stator and a second subgroup of coils positioned consecutively around the

circumference of the stator, the second subgroup of coils may be positioned at a location on the circumference of the stator spaced 180 degrees from a position of the first subgroup of coils on the circumference of the stator. When the plurality of switches are controlled to connect the plurality of coils into the at least first force expansion topology configuration, the arrangement of coils of each of the one or more phases may include a series arrangement of coils or groups of coils from the first subgroup of coils interspersed with coils or groups of coils from the second subgroup of coils. When the plurality of switches are controlled to connect the plurality of coils into the at least first force expansion topology configuration, one or more of the coils or groups of coils from the first subgroup of coils may be wound in a first direction and one or more of the coils or groups of coils from the first subgroup of coils may be wound in a second direction, opposite the first direction; and one or more of the coils or groups of coils from the second subgroup of coils may be wound in the first direction and one or more of the coils or groups of coils from the second subgroup of coils may be wound in the second direction. When the plurality of switches are controlled to connect the plurality of coils into the at least second force expansion topology configuration, each of the one or more phases may include an arrangement of coils, the arrangement of coils may include a first, a second, a third, and a fourth subgroup of coils positioned at locations on the circumference of the stator spaced 90 degrees apart. When the plurality of switches are controlled to connect the plurality of coils into the at least third force expansion topology configuration, each of the one or more phases may include an arrangement of coils, the arrangement of coils may include a first, a second, a third, a fourth, a fifth, and a sixth subgroup of coils, the first, the second, and the third subgroups may be positioned at non-consecutive locations on the circumference of the stator spaced 180 degrees from locations of the fourth, the fifth, and the sixth subgroups.

The reconfigurable rotating electric machine may include rotor position sensors, wherein a first set of sensors is read when the plurality of switches are controlled to connect the plurality of coils into the at least first force expansion topology configuration; and a second set of sensors, separate from or partially overlapping the first set of sensors, is read when the plurality of switches are controlled to connect the plurality of coils into the at least second force expansion topology configuration. The reconfigurable rotating electric machine may further include rotor position sensors operably coupled to a pulse converter, wherein the pulse converter adjusts timing of pulses received by the pulse converter based at least in part on whether the plurality of switches are controlled to connect the plurality of coils into the at least first force expansion topology configuration or the at least second force expansion topology configuration.

A method to change topology configurations in a reconfigurable rotating electric machine may be summarized as including: determining, based on a received sensor signal measuring a parameter of an operational electric machine, whether to switch to an alternative coil topology configuration; decreasing motor drive current, if the determining indicates to switch to the alternative coil topology configuration, over a specified release time period; initializing, upon determining that motor current is below a specified threshold, routine for changing coil topology configuration; applying signals to specified switches, arranged to connect coils or groups of coils to form a plurality of defined coil topology configurations, to establish the alternative coil topology

configuration; determining whether switches are in correct position for the alternative coil topology configuration; and increasing motor drive current, upon determining that the switches are in correct position for the alternative coil topology configuration, over a specified ramp time period.

The method may further include determining whether the switches are off, wherein the applying of the signals to the specified switches to establish the alternative coil topology configuration is performed upon determining that the switches are off. The method further comprising changing a motor drive algorithm based at least in part on the alternative coil topology configuration. The method may further include changing a motor commutation algorithm based at least in part on the alternative coil topology configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a diagram of system in which electrical power is retrieved from an energy storage system to produce mechanical energy and in which electrical power is generated by mechanical energy and stored in the energy storage system, according to one or more implementations.

Figure 2 shows a diagram of a system for controlling power provided to a motor, according to one or more implementations.

Figure 3 shows a diagram of interconnections of communication interfaces of various subsystems of the system, according to one or more implementations. Figure 4 shows a battery module, associated with a battery management system, that controls charging and discharging of individual battery cells within the battery module, according to one or more implementations.

Figure 5 shows a schematic diagram illustrating various aspects of a motor controller, according to one or more implementations.

Figure 6 is a diagram of an electromotive system for applying electromotive force to a load, according to one or more implementations.

Figure 7 shows a graph representative of different coil topology configurations of the motor implemented to cause the motor to exhibit certain

performance characteristics, according to one or more implementations.

Figure 8 is a motor having coils that generate electrical current as a result of an electromagnetic field directed there through, according to one or more

implementations.

Figure 9 shows a first coil configuration of the motor, according to one or more implementations.

Figure 10 shows a second coil configuration of the motor, according to one or more implementations.

Figure 11 shows a third coil configuration of the motor, according to one or more implementations.

Figure 12 shows a representation illustrating a comparison between performance characteristics of the motor as a result of the first, second, and third coil configurations, according to one or more implementations.

Figure 13 shows a diagram representative of terminals of the coils of the motor in a base unconnected configuration of coil pairs, according to one or more implementations.

Figure 14 shows an example of information organized into a lookup table specifying connections of terminals of the coils, according to one or more

implementations. Figure 15 shows a first coil topology configuration of the coils represented in the base unconnected configuration, according to one or more implementations.

Figure 16 shows a second coil topology configuration of the coils represented in the base unconnected configuration, according to one or more implementations.

Figure 17 shows a third coil topology configuration of the coils represented in the base unconnected configuration, according to one or more implementations.

Figure 18 shows a diagram illustrating connections of a set of solid-state switching devices between terminals of the coils of the motor, according to one or more implementations.

Figure 19 shows a lookup table that may be used to determine how to control respective switching devices to implement corresponding coil topology configurations, according to one or more implementations.

Figure 20 shows a block diagram of an implementation of a subsystem for controlling a switching matrix of solid-state switching elements to implement a coil topology configuration.

Figure 21 shows a block diagram of another implementation of a subsystem for controlling a switching matrix of solid-state switching elements to implement a coil topology configuration.

Figure 22 shows a magnetic expansion that combines coils into groupings to form two virtual poles, according to one or more implementations.

Figure 23 shows a magnetic expansion that combines coils into groupings to form four virtual poles, according to one or more implementations.

Figure 24 shows a magnetic expansion that combines coils into groupings to form six virtual poles, according to one or more implementations.

Figure 25 is a graph representing of drive current during a transient prevention process for a coil configuration switching event, according to one or more implementations. Figures 26A and 26B present a diagram of a process for performing a coil configuration switching event which includes a transient prevention process, according to one or more implementations.

DETAILED DESCRIPTION

This application claims priority to U.S. Provisional Patent Application No. 62/727,483, filed September 5, 2018, which is hereby incorporated by reference in its entirety.

Systems and methods are described and illustrated herein that control and optimize rotating electric machines. Disclosed implementations provide for a rotating electric machine to adopt a set of performance characteristics, selected based on specific operating conditions from among multiple sets of performance characteristics, by changing the coil configurations of the electric machine during rotation. In

implementations, the electric machine is designed or modified so that both leads from each coil can be accessed and interconnected in specified configurations. Alternatively, coils may be maintained and internally connected in discrete coil groups and these groups may be interconnected in specified configurations.

Along with the reconfigurable machine, the described technologies include a system-level approach to energy capture, storage, and release through use of system-level elements able to provide coordinated feedback and optimization for all system components. A reconfigurable power generator may be coupled with a reconfigurable energy storage system to provide for optimized operations of the system. This can provide improvements to the utilization of the battery energy to drive the machine in motor mode, as well as when operating in generator mode. A control system is provided that can control power output characteristics of a rotating electric machine operating as a motor or as a power generator.

In implementations, there may be various different configurations available for the electric machine, which may operate as only a generator, only as a motor, or as both a generator and a motor, e.g., as in four-quadrant operations. When employed in an application, each of the winding topologies creates a new speed-torque profile much like a mechanical gearbox would. Because the disclosed system, in effect, serves the function of a mechanical gearbox, but does so electrically, the electrical configurations of an application may be referred to as“electrical gears.”

The ability to control output from the machine in generator mode allows the system the ability to maintain more ideal charging conditions across a broader range of operations than traditional systems. Voltage outputs from typical renewable energy systems are determined by the speed of the prime mover, and additional power conditioning is often required to attain voltages high enough to charge batteries (or even just to accommodate the load). This might be done with buck or boost converters but using these devices will result in increased power losses and may require more expensive and complex components. The reconfigurable power generator and energy storage systems described herein provide improved operations regardless of prime mover conditions. The improved efficiency of the system means greater economic benefit, as well as greater range in battery-powered transportation applications.

The operating conditions of each system component may be monitored and shared with the control system. As a result, the control system may provide directives for each of the lower level elements to ensure seamless, optimized overall operations of the system and to achieve more efficient energy conversion, storage, and provisioning.

The process for switching the coils under load represents the core technical challenge for this technology. If the switching event is not properly managed, substantial electrical transients may be produced. These transients can easily damage systems and may even be dangerous depending upon power levels. There are two phenomena to be managed due the effects of the switching event. One phenomenon is an electrical transient which arises at the instant the coils are disconnected from the drive and the other is a current transient which occurs when the rotating electric machine is re-connected to the drive (i.e. , when current is reapplied to the machine coils). There are various means by which undesirable transients caused by switching events can be managed. The most desirable solution may depend upon the type of system. For example, if the motor uses rotor position feedback data from Hall sensors and if the motor drive is field oriented control (FOC), then that may lead to a particular design to attenuate the transients. If, on the other hand, the system is a simple 6-step drive that uses sensor-less observers that attempt to use the back EMF signal of the motor for commutation, then that would suggest an alternative strategy to manage the switching transients. Also, the power level of the system affects the ultimate design. The application and power level for the rotating electric machine as well play a role in determining the best overall design. As a general rule, higher power systems require more complex solutions that must minimize transient production by not allowing the system to create it in the first place. Lower power systems and those that are less complex may allow the transients to happen, i.e. , may not include transient prevention circuitry, but can employ circuit designs that absorb the electrical spikes.

In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed implementations. However, one skilled in the relevant art will recognize that implementations may be practiced without one or more of these specific details, or with other methods, components, materials, etc. In other instances, well-known structures associated with computer systems, server computers, and/or communications networks have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the implementations.

Unless the context requires otherwise, throughout the specification and claims that follow, the word“comprising” is synonymous with“including,” and is inclusive or open-ended (i.e., does not exclude additional, unrecited elements or method acts).

Reference throughout this specification to“one implementation” or“an implementation” means that a particular feature, structure or characteristic described in connection with the implementation is included in at least one implementation. Thus, the appearances of the phrases“in one implementation” or“in an implementation” in various places throughout this specification are not necessarily all referring to the same implementation. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more implementations.

The headings and abstract provided herein are for convenience only and do not interpret the scope or meaning of the implementations.

Figure 1 shows a system 100 in which electrical power is retrieved from an energy storage system 110 to produce mechanical energy and in which electrical power is generated by mechanical energy and stored in the energy storage system 110, according to one or more implementations. The system 100 includes a load/mechanical energy source 102, a motor/power generator 104, a motor/power generator control system 106, an energy storage system 110, an energy storage control system 108. The load/mechanical energy source 102 includes a rotational element, e.g., a wheel of a vehicle, that is rotated by mechanical energy provided by the motor/power generator 104. Also, when the rotational element is rotated by an external force, e.g., downhill movement of a vehicle, the rotational element provides mechanical energy to the rotor of the motor/power generator 104. The motor/power generator 104 includes a stator which operates in conjunction with the rotor to provide and receive mechanical energy from the load/mechanical energy source 102.

The motor/power generator control system 106 may control switching elements, such as solid-state switches and relays, provided between coils of the motor/power generator 104. Coil configuration changes may alter the configuration of one coil relative to another coil or the configuration of a first set of coils relative to a second set of coils. For example, the motor/power generator control system 106 may cause a set of the coils to be connected in parallel with each other or cause a set of the coils to be connected in series with each other. Additionally, coils may be selected and combined from different phases to create a specified configuration.

The motor/power generator control system 106 may be electronically communicatively coupled to one or more sensors for determining operating

characteristics of the motor/power generator 104. In at least some implementations, the motor/power generator control system 106 may be coupled to one or more angular sensors for determining a rotation angle of the rotor relative to the stator of the motor/power generator 104. The motor/power generator control system 106 may determine the speed of rotation of the rotor and thereby determine the corresponding power output capability of the motor/power generator 104.

Figure 2 shows a schematic diagram of a system 200 for controlling power provided to a motor according to one or more implementations. The system 200 includes one or more of the constituent parts comprising the system 100 described herein with respect to Figure 1. The system 200 may be a power provisioning system of a car or other device, or part of a residential or commercial power infrastructure. The system 200 may include a plurality of battery packs 202 that each comprise one or more battery modules which, in turn, comprise a number of battery cells (e.g., 30 battery cells, in the example depicted). The battery packs 202 are part of the energy storage system 110 described herein.

The system 200 may further include a dynamic power management (DPM) unit 214 that controls a topology configuration of the coils of the motor 212 to generate mechanical energy and electrical power. The coils are inductive coils that, as a result of receiving AC current from the motor controller 210, cause the motor 212 to produce an electromotive force. The DPM unit 214 may cause coils of the system 200 to modify a topology configuration of some or all of the coils to be connected in series or in parallel with each other, as described in further detail below. The DPM 214 may cause the coils to be connected in a particular configuration topology to cause the motor 212 to operate in a high-performance mode (e.g., increased torque, increased speed) or a high-efficiency mode depending on signals received from the CPCU 206. The topology configuration of the coils may be synchronously controlled with the motor controller 210. For instance, one or more commands sent from the CPCU 206 may cause the motor controller 210 and the DPM 214 to perform operations in fulfillment of the one or more requests at the same time. The DPM 214 may include one or more processors and memory storing a set of instructions that, as a result of execution by the one or more processors, cause the DPM 214 to perform as described herein. The memory may further store parameters related to operation of the DPM 214, and the one or more processors may generate statistics and other information regarding

performance of the DPM 214. A debug interface of the DPM 214 is electronically communicatively coupled to the one or more processors for debugging and/or reprogramming operation of the DPM 214. The debug interface may include one or more of a serial peripheral interface (SPI), a differential serial interface (e.g., RS422), and a secure wireless interface. Thus, operation and performance of the motor is controlled, at least in part, based on operations of the DPM 214 and the motor controller 210.

Figure 3 is a communication diagram showing interconnection of communication interfaces of various subsystems of the system 200. The system 200 may include one or more busses for transferring data, commands, control signals, etc., between components of the system 200. A main bus 302 is a controller area network bus over which processors (e.g., microcontrollers) of the components can communicate with each other. In some implementations, the components of the system 200 may communicate with each other over the main bus 302 without a central network host that facilitates communications between the components. A central power data (CPD) bus 304 is provided for transporting data regarding power between components of the system 200. A central power synchronization (CPS) bus 306 is provided for transporting signals related to synchronization of power characteristics and events. Various components of the system 200 may also be communicatively coupled via Precision Time Protocol (PTP) communication buses or connections 308. Communications over PTP connection 308 facilitates synchronization of clocks of various components down to the nanosecond scale to ensure that control and operations of the connected

components occur at precise times relative to each other. A first PTP connection 308 may connect the DPM 214 and the motor controller 210, a second PTP connection 308 may connect the CPCU 206 and the main contactor 208, and one or more third PTP connections 308 may connect battery management systems 400 (see Fig. 4) of different battery pack 202. The integrated communication/control subsystem thus enables the exchange of information between system components to provide efficient operation of each component in the system, which, in turn, may provide a more capable and higher efficiency collective system overall. For example, in a renewable energy system, where the prime mover is inherently variant, and where the load characteristic may also be in a state of change, the control algorithm for the described system may assess both variables in order to select the most optimal mode of operation. The system may as well employ various algorithms, and/or artificial intelligence, as a means to further optimize the system. Through collecting data for a given application, the system may assess probabilities and predict expected operational changes over time for a given application. For example, in a wind energy application, the implications of a configuration change will be known by the controller and the effects of a configuration change will be factored into the assessment of the viability of each configuration change and how that change is expected to affect the system. In implementations, a portion of the power output may go to charge a battery while another portion accommodates the load requirements. This may be well-suited for a host of applications such as capturing renewable energy sources such as wind, run of river, tidal, wave, etc.

As shown in Figure 4, a battery module 402 may be associated with a battery management system 400 that controls charging and discharging of individual battery cells within the battery module 402. As noted above, a number of battery modules 402 may be combined to form a battery pack 202 (see Fig. 2). One or more battery cells may be under the control of each battery management system 400 - for instance, thirty battery cells may be combined in a battery module 402 under the control of the battery management system 400 to produce a battery module output of up to 96 volts. The battery management system 400 may include a first interface 404 for interfacing with one or more battery modules 402 and a second interface 406 for interfacing with a topology switching subsystem 204 (see Fig. 2) described below. A power unit 408 may control the provisioning of power between the first interface 404 and the second interface 406. The power unit 408 may include a plurality of switching elements that are operable to control the flow of power between one or more interfaces of the first interface 404 and one or more interfaces of the second interface 406.

Examples of switching elements of the power unit 408 include solid-state switches, such as metal oxide semiconductor field effect transistors (MOSFETs), bi-polar junction transistors (BJTs), diodes, and thyristors; and include electromechanical switches, such as relays. The switching elements may be operable to selectively control charging to, and discharging from, individual battery cells.

The battery management system 400 may further include a communication interface 410 for sending and receiving data, communications, control signals, etc., to and from other portions of the system 200. The communication interface 410 may be connected to a variety of operational networks and busses, including Control Area Networks (CAN), Precision Time Protocol (PTP) networks, Central Power Data (CPD) networks, and Central Power Synchronization (CPS) networks. The battery management system 400 may also include a sensor interface 412 that interfaces with one or more sensors associated with one or more of the battery cells in the battery modules 402 for obtaining measurements regarding a condition of the battery cells. The sensors may provide measurements regarding a voltage level, current input, current output, charge level, temperature, etc., of the associated battery cell or cells.

The battery management system 400 may further include one or more processors 414 for controlling operation of the battery management system 400, controlling charging/discharging of the battery cells and the power unit 408, sending and receiving communications over the communications interface 410, and receiving measurements from the sensor interface 412. The processor(s) 414 may take any one or more of a variety of forms, including but not limited to: one or more microcontrollers, microprocessors, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), graphics processing units (GPUs), digital signal processors (DSPs), and/or programmed logic controllers (PLCs). The battery management system 400 may include one or more nontransitory computer- or processor-readable media, for instance memory (e.g., volatile memory, nonvolatile memory, random-access memory, read-only memory, Flash memory, solid state drive memory, spinning media storage such as magnetic disks, optical disks) storing instructions that, as a result of being executed, cause the battery management system 400 to perform the operations described herein. The memory may store a set of instructions causing the battery management system 400 to control charging, discharging, and connection of the battery cells of the battery modules 402 to other components for performance or protection- related purposes. The battery management system 400 may also perform operations according to communications, commands, control signals, etc., received from the CPCU 206.

Figure 5 shows a schematic diagram illustrating various aspects of the motor controller 210. Operation of the motor controller 210 may affect aspects of operation of the motor 212, such as speed, current, torque, modulation index, temperature, etc. The motor controller 210 may include power input 502 for receiving DC power, one or more inverters 504 for converting DC power received into AC power, and power output 506 for outputting the converted AC power. The motor controller 210 may include a communications interface 508 for sending and receiving communications on a communications bus of the system 200, and a sensor interface 510 for receiving feedback from one or more sensors associated with the motor 210.

The motor controller 210 may also include one or more processors 512 for processing information received, generating information (e.g., communications), and controlling one or more aspects related to power conversion. The motor controller 210 may include memory storing instructions that, as a result of execution by the one or more processors 512, cause the motor controller 210 to perform operations described herein. The motor controller 210 may receive feedback from one or more sensors associated with the motor 212 that measure various aspects of motor performance and operation, including the speed, temperature, torque, etc. The motor controller 210 may receive instructions, commands, or control signals, e.g., from the CPCU 206, indicating ranges, thresholds, or values for motor performance and operation. For instance, the motor controller 210 may receive a control signal from the CPCU 206 indicating a speed at which the motor 212 should operate, and the motor controller 210 may control electrical characteristics of power provided to the motor 212 to cause the motor 212 to operate at the speed indicated. The motor controller 210 may include a debug interface 514 for interfacing with other processor-based devices debugging and reprogramming aspects of the motor controller 210.

Figure 6 is a diagram of an electromotive system 600 for applying electromotive force to a load according to one or more implementations. The

electromotive system 600 corresponds to at least a portion of the system 200 described herein. The system 600 includes a DC power supply 602 corresponding to the battery pack 202, a motor drive 604 corresponding to the motor controller 210, a coil configuration unit (CCU) 606 corresponding to the DPM 214, and a motor 608 corresponding to the motor 212. The motor 608 is configured to produce an

electromotive force, for example, that may rotate or otherwise move a load 610. The motor 608 may be a 3-phase permanent magnet motor . The CCU 606 may change the coil topology configuration of the motor 608 to adjust performance attributes of the motor 608. The CCU 606 may modify a topology configuration of the motor 608 in response to input received via an input 612 provided by a user or other component of the system. The electromotive system 600 may be a part of a drive train of a vehicle.

Relationships between rotating electric machine inductors/coils may be reconfigured by the CCU 606 to be in series, parallel, or compound (i.e. , a combination of series and parallel) and also may be reconfigured in such a way as to significantly vary the magnetic field distribution of the stator and/or rotor. This coil reconfiguration technology is referred to herein as“magnetic force expansion.” The approaches described herein may be applied to a permanent magnet machine in which the stator windings are reconfigured to interact with the permanent magnetic fields of the rotor. Furthermore, various other types of electric machines can also benefit from these approaches, including all types of electric machines with windings that comprise the stator and or rotor. As discussed below, electric machine windings that are configured in an all-parallel configuration provide substantially different characteristics than those in an all-series configuration and such differences can be exploited to achieve performance benefits. Furthermore, the disclosed implementations can employ various combinations of series and parallel windings to accommodate the desired operating conditions and achieve further performance benefits. Moreover, an electric machine may use groupings of magnetic influences within the motor/generator to achieve even further performance benefits. For example, groupings which form, actually or in effect, a 2-pole machine design will operate substantially differently than groupings which form, in effect, a 4-pole or a 6-pole machine and such differences can be advantageous in achieving desired electric machine characteristics and performance. The term“virtual pole” is used herein to refer to configurations and groupings of coils which effectively form additional poles (“effective pole” is an alternative term for this phenomenon) by dint of their effect on the magnetic characteristics of the windings. In this way, a motor which is wound to be a 2- pole machine can be reconfigured to have four virtual poles, six virtual poles, etc. Such a machine may be described as having two virtual poles, even though the machine windings in their unmodified or“default” configuration may form two conventional poles.

In implementations, coil configurations that mix and interconnect coils of different phases may provide substantial operational benefits. Such configurations, in effect, shift the magnetic poles of the electric machine and/or create additional virtual poles, thereby potentially providing operational benefits beyond those achieved through use of parallel, compound, or series winding configurations alone. The coil configuration for a given system may be determined based at least in part on the requirements of the particular application, which may specifically call for series/parallel configurations, a combination of series/parallel configurations along with magnetic force expansions, or the use magnetic force expansion alone.

This type of reconfigurable machine can work with other control systems, as well as various power conditioning systems, such as passive or active rectification, single or multilevel power converters, and various power optimization elements that manage power characteristics and quality.

Figure 7 shows a graph 700 representative of different coil topology configurations of the motor 608 implemented by the CCU 606 to cause the motor 608 to exhibit certain performance characteristics. The graph 700 depicts performance characteristics of torque relative to speed; however, the CCU 606 may adjust the coil topology configuration according to other performance attributes, such as efficiency.

The coil configuration topologies for the various performance are described below. A first region 702 of the graph 700 corresponds to a default coil topology configuration in which the motor 608 is operating in a range in which speed and torque are balanced. A second region 704 of the graph 700 corresponds to a high-speed configuration in which the motor 608 exhibits performance characteristics favoring speed over torque. A third region 706 of the graph 700 corresponds to a high-torque configuration in which the motor exhibits performance characteristics favoring production of torque over speed.

Figure 8 is a motor 800 having a plurality of coils 802 that generate electrical current as a result of an electromagnetic field directed there through. The motor 800 is an out-runner permanent magnet motor with 24 coils in the stator and 22 magnets in the rotor. The motor 800 may be connected to the CCU 606 described herein, which modify the topology configuration of the coils 802 to rotate a rotor 804 according to different performance characteristics, such as those described with respect to Figure 7. Each of the coils 802 are depicted as having a corresponding numeral for ease of description. In implementations, the coils may be grouped into a first set 810 and a second set 820 to form one of the three phases of the motor, as explained below.

Figure 9 shows a first coil configuration 900 of the coils 802 of the motor 800 according to one or more implementations. The first coil configuration 900 is a coil topology configuration formed by the CCU 606, and corresponds to the default coil configuration described above with respect to the first region 702 of Figure 7. In the first coil configuration 900, the coils 802 are organized into three phases: a first phase 902, a second phase 904, and a third phase 906. Each phase is comprised of eight coils and each phase is respectively structured in two parallel groups of four consecutive coils arranged in series. The four consecutive coils arranged in series of an individual phase are adjacent around the circumference of the stator, each 15° apart, and parallel groups are located 180° apart from each other. For instance, the first phase 902 is comprised of a first set of coils (coils 1 , 2, 3, 4 in Figure 8) consecutively spaced apart at 15° and a second set of coils (coils 13, 14, 15, 16 in Figure 8) consecutively spaced apart at 15° and each respectively positioned across from a corresponding coil of the first set of coils. The first set of coils of the first phase 902 is arranged in parallel with the second set of coils. The second phase 904 and the third phase 906 have a similar configuration to the first phase 902 but spaced apart 60° from the first phase 902. The first coil configuration 900 causes the motor 800 to exhibit performance characteristics balancing speed and torque (/. e. , performance characteristics in the first region 702 of Figure 7).

Figure 10 shows a second coil configuration 1000 of the coils 802 of the motor 800 according to one or more implementations. The second coil configuration 1000 is a coil topology configuration formed by the CCU 606, and corresponds to the high torque configuration described with respect to the third region 706 of Figure 7. The coils 802 in the second coil configuration 1000 are organized into a first phase 1002, a second phase 1004, and a third phase 1006. Each phase is comprised of eight coils and each phase is respectively structured into a single series group of eight coils. The singles series group is comprised of a first set of coils (coils 1 , 2, 3, 4 in Figure 8) consecutively spaced apart at 15° and a second set of coils (coils 13, 14, 15, 16 in Figure 8) consecutively spaced apart at 15° and each respectively positioned across from a corresponding coil of the first set of coils. The first set of coils of the first phase 1002 is arranged in series with the second set of coils. The second phase 1004 and the third phase 1006 have a similar configuration to the first phase 1002 but spaced apart 60° from the first phase 1002. The second coil configuration 1000 causes the motor 800 to exhibit performance characteristics favoring higher production of torque (/.e., performance characteristics in the third region 706 of Figure 7). Figure 11 shows a third coil configuration 1100 of the coils 802 of the motor 800 according to one or more implementations. The third coil configuration 1100 is a coil topology configuration formed by the CCU 606, and corresponds to the high speed configuration described with respect to the third region 704 of Figure 7. In the third coil configuration 1100, the coils 802 are organized into three phases: a first phase 1102, a second phase 1104, and a third phase 1106. Each phase is comprised of eight coils and each phase is respectively comprised of two groups of coils 802 arranged in parallel. Each group of each phase is comprised of two subgroups of coils, each subgroup comprised of adjacent coils spaced apart at 15° and consecutive subgroups being spaced apart at 90°. For example, the first phase 1102 is comprised of a first group 1108 of four coils 802 and a second group 1110 of four coils 802 connected in parallel to the first group 1108. The first group 1108 is comprised of a first subgroup 1112 of consecutive coils (coils 1 , 2 of Figure 8) and a second subgroup 1114 of consecutive coils (coils 7, 8 of Figure 8) that are spaced apart at 90° from the respective coils of the first subgroup 1112. The second group 1110 of coils comprises two subgroups that are respectively spaced apart at 180° and 270° from the first subgroup 1112. The second phase 1104 and the third phase 1106 have a similar configuration to the first phase 1102 but spaced apart 60° from the first phase 1002. The second coil configuration 1100 causes the motor 800 to exhibit performance characteristics favoring higher production of speed (/. e. , performance characteristics in the second region 704 of Figure 7).

Figure 12 shows a representation illustrating a comparison between performance characteristics of the motor 800 as a result of the first coil configuration 900, the second coil configuration 1000, and the third coil configuration 1100. A first graph 1202 is representative of performance characteristics of the motor 800 as a result of the coils 802 being connected in the first coil configuration 900, which causes the motor 800 to exhibit performance characteristics balancing speed and torque. A second graph 1204 is representative of performance characteristics of the motor 800 as a result of the coils 802 being connected in the second coil configuration 1000, which causes the motor 800 to exhibit performance characteristics favoring torque. A third graph 1206 is representative of performance characteristics of the motor 800 as a result of the coils 802 being connected in the third coil configuration, which causes the motor to exhibit performance characteristics favoring speed.

Figure 13 shows a diagram representative of terminals of the coils 802 of the motor 800 in a base unconnected configuration 1300 of coil pairs 1302, according to one or more implementations. Pairs 1302 of consecutive coils 802 of the motor 800 are serially connected, each pair having a first terminal 1304 and a second terminal 1306 each of which can be connected to another terminal of the motor 800. In some implementations, each coil 802 may have a pair of terminals 1304 and 1306 or there may be more than two coils for each pair of terminals. There are twelve pairs 1302 of coils in the base unconnected configuration 1300 corresponding to the twenty-four coils 802 of the motor 800. The consecutive numerals between 1 and 24 depicted in Figure 13 correspond to the numerals depicted in Figure 8 such that adjacent coils have adjacent numerals, with the exception that the coil represented by the numeral“1” is adjacent to the coil represented by the numeral“24.” The CCU 606 and/or the DPU 214 form coil topology configurations by connecting terminals of the pairs 1302. Connections between terminals of different pairs 1302 of coils 802 may be formed by controlling solid-state switching elements, such as MOSFETs or thyristors (e.g., silicon-controlled rectifier).

Figure 14 shows an example of information organized into a lookup table 1400 specifying connections of terminals of the coils 802. The CCU 606 may receive input information from the lookup table 1400, or other type of data structure, specifying a coil topology configuration to form. The CCU 606 may determine how to form the coil topology configuration specified by referencing information stored in memory of or accessible by the CCU 606. The lookup table 1400 includes columns each

corresponding to a terminal of the coil pairs 1302 and rows corresponding to a coil topology. Each entry 1404 of the lookup table 1400 specifies a terminal to which the respective terminal of a column is to be connected to satisfy the coil topology configuration. The lookup table 1400 may be further organized into sub-tables corresponding to different phases of the motor 800. The lookup table 1400 includes a first set of entries 1406 for implementing a first coil topology configuration,“Default,” a second set of entries 1408 for implementing a second coil topology configuration,“High Torque,” and a third set of entries 1410 for implementing a third coil topology

configuration,“High Speed.” The lookup table 1400 may also specify connections for a power input node“PIN,” and connections to a neutral node“N.” There may be more or fewer sets of entries than those described and illustrated with respect to Figure 14. The CCU 606 may access the lookup table 1400 stored memory in response to receiving a request to implement a particular coil topology configuration. The request may specify an alphanumeric value corresponding to a set of entries to be implemented. Control by the CCU 606 may use other data structures, such as a logic ladder, or may use far more complex control strategies such as advanced self-optimizing neural networks or machine learning systems.

Figure 15 shows a first coil topology configuration 1500 of the coils represented in the base unconnected configuration 1300 according to one or more implementations. The first coil topology configuration 1500 corresponds to the first coil configuration 900, which causes the motor 800 to exhibit performance characteristics balancing speed and torque. To implement the first coil topology configuration 1500, the CCU 606 causes a set of connections to be established between terminals of the coils according to the sets of entries defined in the lookup table 1400. The CCU 606 may reference the first set of entries 1406 to fulfill a command or request to implement the first coil topology configuration 1500. According to the first set of entries 1406, the CCU 606 establishes a first connection 1502 between terminals A1 and A5, a second connection 1504 between terminals A2 and A3, a third connection 1506 between terminals A4 and A8, and a fourth connection 1508 between terminals A6 and A7. The connections 1502, 1504, 1506, and 1508 establish the first phase 902 of the first coil configuration 900. The second phase 904 and the third phase 904 are established by the CCU 606 according to the remaining entries in the lookup table 1400. The fourth connection 1508 is connected to other terminals of the second phase 902 and the third phase 904. A fifth connection 1510 connects a power input node PIN to the terminal A5, and a sixth connection 1512 connects the neutral node N to the terminal A4.

Figure 16 shows a second coil topology configuration 1600 of the coils represented in the base unconnected configuration 1300 according to one or more implementations. The second coil topology configuration 1600 corresponds to the second coil configuration 1000, which causes the motor 800 to exhibit performance characteristics favoring higher torque. To implement the second coil topology

configuration 1600, the CCU 606 causes a set of connections to be established between terminals of the coils according to the sets of entries defined in the lookup table 1400. The CCU 606 may reference the second set of entries 1408 to fulfill a command or request to implement the second coil topology configuration 1600.

According to the second set of entries 1408, the CCU 606 establishes a first connection 1602 between terminals A1 and A8, a second connection 1604 between terminals A2 and A3, a third connection 1606 between terminals A4 and the neutral node N, a fourth connection 1608 between terminals A6 and A7, and a fifth connection 1610 of the terminal A5 to the power input PIN. The connections 1602, 1604, 1606, 1608, and 1610 establish the first phase 1002 of the second coil configuration 1000. The second phase 1004 and the third phase 1004 are established by the CCU 606 according to the remaining entries in the lookup table 1400.

Figure 17 shows a third coil topology configuration 1700 of the coils represented in the base unconnected configuration 1300 according to one or more implementations. The third coil topology configuration 1700 corresponds to the third coil configuration 1100, which causes the motor 800 to exhibit performance characteristics favoring higher speed. To implement the third coil topology configuration 1700, the CCU 606 causes a set of connections to be established between terminals of the coils according to the sets of entries defined in the lookup table 1400. The CCU 606 may reference the third set of entries 1410 to fulfill a command or request to implement the third coil topology configuration 1700. According to the third set of entries 1410, the CCU 606 establishes a first connection 1702 between terminals A1 and A5, a second connection 1704 between terminals A2 and B3, a third connection 1706 between terminals B4 and B8, a fourth connection 1708 between terminals A6 and B7, a fifth connection 1710 of the terminal A5 to the power input PIN, and a sixth connection 1712 of the terminal B8 to the neutral point. The connections 1702, 1704, 1706, 1708, 1710, and 1712 establish the first phase 1102 of the third coil configuration 1100. The second phase 1104 and the third phase 1104 are established by the CCU 606 according to the remaining entries in the lookup table 1400.

Figure 18 shows a diagram illustrating connections of a set of solid-state switching devices (e.g., Q1 , Q2, Q3... ) between terminals of the coils 802 of the motor 800. To create a switching matrix capable of switching between the coil topology configurations 1500, 1600, and 1700, a plurality of solid-state switching devices (e.g., Q1 , Q2, Q3... ) are electronically coupled to between terminals of various coils 802 of the motor 800. To implement the three coil topology configurations described herein, a set of seven solid-state switching devices are implemented per phase. The solid-state switching devices depicted in the diagram are MOSFETs, but various solid-state switching devices other than MOSFETs may be used.

The source and drain terminals of the respective MOSFETs are connected to corresponding terminals of the coils 802 and the CCU 606 is electronically

communicatively coupled to the gate terminals of the MOSFETs. Respective terminals of a first switching device 1802 are connected to terminals A1 and A5 of the coils 802 to selectively establish a connection therebetween, such as the first connection 1502 of the first coil topology configuration 1500. Respective terminals of a second switching device 1804 are connected to terminals A4 and A8 of the coils 802 to selectively establish a connection therebetween, such as the third connection 1506 of the first coil topology configuration 1500. Respective terminals of a third switching device 1806 are connected to terminals A1 and A8 of the coils 802 to selectively establish a connection therebetween, such as the first connection 1602 of the second coil topology

configuration 1600. Respective terminals of a fourth switching device 1808 are connected to terminals A2 and A3 to selectively establish a connection therebetween, such as the second connection 1504 of the first coil topology configuration 1500.

Respective terminals of a fifth switching device 1810 are connected to terminals A6 and A7 to selectively establish a connection therebetween, such as the fourth connection 1508 of the first coil topology configuration 1500. Respective terminals of a sixth switching device 1812 are connected to terminals A2 and B3 to selectively establish a connection therebetween, such as the second connection 1704 of the third coil topology configuration 1700. Respective terminals of a seventh switching device 1814 are connected to terminals A6 and B7 to selectively establish a connection therebetween, such as the fourth connection 1708 of the third coil topology configuration 1700. Each phase has its own set of MOSFETs to control the connections between nodes thereof and/or nodes of other phases. The CCU 606 may control an electrical signal applied to the gate terminal of the respective MOSFETs to control a state of the MOSFETs - namely, whether respective ones of the MOSFETs are in an ON state conducting current between source and drain terminals or in an OFF state inhibiting current flow between source and drain terminals.

Figure 19 shows a lookup table 1900 that may be used, e.g., by the CCU 606, to determine how to control respective switching devices to implement

corresponding coil topology configurations. The lookup table 1900 comprises a set of entries 1902 each defining a state for a particular one of the solid-state switching devices (e.g., Q1 , Q2, Q3... ) depicted in Fig. 18 for a corresponding coil topology configuration. The lookup table 1900 is organized into rows 1904 that each correspond to a particular coil topology configuration and columns 1906 that each correspond to a particular one of the solid-state switching devices.

Figure 20 shows a block diagram of a subsystem 2000 for controlling a switching matrix 2002 comprising a plurality of solid-state switching elements to implement a coil topology configuration. The subsystem 2000 includes a microcontroller unit 2004 (MCU) that may be part of the CCU 606 described herein. The MCU 2004 receives user input 2006, via an input interface of the system 200 or the CCU 606, indicating a particular coil topology configuration for the CCU 606 to implement. The MCU 2004 controls a set of gate drivers 2008 to control a state of corresponding solid- state switches of the switching matrix 2002 based on the user input 2006 received to implement the corresponding coil topology configuration. The set of gate drivers 2008 include gate driver circuitry that can be operated to selectively apply an electrical signal to gates of the solid-state switching devices to transition the switching devices between an OFF state and ON state. Individual gate drivers of the set of gate drivers 2008 may control one or more corresponding switching devices of the switching matrix 2002. The gate drivers may include a thyristor or SCR that, as a result of receiving a control signal, provides a voltage from one or more power sources (not shown) to one or more gates. The gate drivers of the subsystem 2000 are electrically isolated from the MCU 2006 such that the SCR gates are activated as a result of receiving an optical signal from a corresponding light-emitting diode; however, the gate drivers may not be electrically isolated in some implementations.

A shift register 2010 is included in the subsystem 2000 that converts serial input from the MCU 2006 to a parallel output provided to the set of gate drivers 2008. Each output bit of the shift register 2010 drives an input signal for a plurality of corresponding solid-state switching devices. In particular, each output bit may drive an input signal for three solid-state switches devices, which each correspond to a connection between the same corresponding terminals of the three-phases of the motor 800. For example, referring to Figure 18, one output bit of the shift register 2010 may control a state of the first switching devices 1802a, 1802b, and 1802c for all three- phases of the motor 800. The shift register 2010 receives output from the MCU 2006 comprising signals from a serial peripheral interface (SPI) and signals from a plurality of General Purpose Input Output (GPIO) interface. Using the shift register 2010 in this manner facilitates a scalable approach in which fewer output bits are required to implement greater numbers of coil topology configurations.

Figure 21 shows another implementation of a subsystem 2100 for controlling a switching matrix comprising a plurality of solid-state switching elements to implement a coil topology configuration. The subsystem 2100 is similar to the subsystem 2000 discussed above, but omits the shift register 2010. The subsystem 2100 represents an implementation in which each GPIO signal provided corresponds to a different gate signal, which may be cheaper to implement but less scalable than the implementation of the subsystem 2000 discussed above.

Figure 22 shows a magnetic expansion that combines coils into unique groupings to form two virtual poles, thereby providing alternative operating characteristic for the machine. In this case the coils are separated into two groupings of three coils. The winding illustration to the left indicates what coil numbers are to be connected and in what order. As well, it shows the winding direction for each coil as either CW

(clockwise) or CCW (counter-clockwise).

Figure 23 shows a magnetic expansion based on the same machine as shown in Figure 22 but which forms a configuration having four virtual poles. The phases are again symmetrical across the three phases, but are not necessarily even, nor evenly distributed. This illustration shows that with this winding scheme, the phases may be comprised or coil groupings, which are evenly distributed around the stator, but the number of adjacent coils per group changes (2, 1 ,2,1 ) in this example. It can be seen the coil 15 and coil 6 are singular windings where coils 1 and 2, as well as coils 10 and 11 , are adjacent to each other. The coil diagram to the left of the stator illustration show the winding schematic for this configuration which include each coil’s winding direction. By virtue of this configuration, the system“borrows” coils from other phases to effectively form additional poles. In the example depicted, instead of grouping coils 1 , 2, and 3, the system groups coils 1 , 2, and 6, with coil 6 having been, in effect, taken from a grouping of coils 4, 5, and 6 which were used by another phase in the configuration of Fig. 22.

Figure 24 shows a magnetic expansion based on the same machine as shown in Figure 22 but which forms a configuration having six virtual poles. Again the same 18 coil machine is configured here to create an alternative force expansion coil configuration for the machine. This six virtual pole configuration is symmetric, with each grouping having the same number of adjacent coils (i.e. , one), but the groupings are not evenly distributed around the stator (only one coil separates certain groupings, while four coils separate other groupings). The schematic to the left of the stator illustration shows the exact winding sequence for this force expansion. In the example depicted, instead of grouping coils 1 , 2, and 3, the system groups coils 1 , 3, and 5, with coil 5 having been, in effect, taken from a grouping of coils 4, 5, and 6 which were used by another phase in the configuration of Fig. 22.

The three examples depicted in Figs. 22-24, discussed above, represent alternative magnetic expansion (or“force expansion”) implementations for an 18-coil machine. Flowever, the disclosed system is not limited to an 18-coil machine (many different stator coil designs may be used), nor is the disclosed system limited to only three possible configurations. The winding configurations of each phase for a force expansion are symmetric in implementations, however the coils that comprise the phases may change to attain the desired effect. In implementations, each grouping of adjacent coils has the same number of coils in it and the groupings are evenly distributed around the stator. Also, although concentrated windings are used in the figures so as to more easily illustrate the concept, the windings may be distributed/lap winding, traces on a circuit board acting as a stator, etc.

In these examples, the magnetic force distribution expansions can be seen in Figs. 22-24 (respectively two, four, and six virtual poles). Additionally, any number of alternative motor designs may be employed with the technology. This includes, but is not be limited, to inner/outer rotor designs, non-permanent magnet machines like the induction machine, brushless DC (BLDC), axial, radial, and

transverse flux.

In implementations, there may be any number of combinations of different coil configurations. For example, implementations may have any number of only parallel/series configurations (including compound windings that are combinations of groups of parallel and series coils). As a further example, implementations may use only the magnetic force expansions configurations, such as a 4-force, 6-force, and 8-force design. Alternatively, implementations may use a combination of parallel/series and force expansion configurations. As an example, for an e-Bike application the switching interface might employ three electrical gears. The three coil configurations provide three operating states that require two switching points. In this example, the first electrical gear might be a series winding configuration (for high torque). As the machine speed increases, the machine then switches to a second electrical gear (which may be the motor’s default mode where a compound winding configuration is used), and as the machine further increases speed the second switching state will transition from the second electrical gear to the third electrical gear which may be a force expansion configuration optimized for the specific machine architecture and the desired application requirements.

As discussed above, in coil configurations with the magnetic force expansion, coils from different phases are combined to create unique magnetic force distributions when power is applied to the machine. The force expansion technology alters the magnetic force distribution in the machine. The new magnetic distribution may require alternative commutation feedback timing to maintain optimal rotor position feedback signals. Consequently, in some implementations, sensor locations for rotor feedback must be altered.

The rotor position sensor relocation required for some machines, in a “force expansion” configuration, may be accommodated a number of ways. Additional hall sensors might be placed on the machine such that those that best represent the new ideal force expansion configuration are available for the system to utilize as an updated set of sensors used for commutation. This technique can be done with one or more additional force expansion configurations (additional hall sensors). The system toggles between various sensors (Hall or otherwise) to create sufficient accurate rotor position data for the system regardless of what coil configuration is being used. A further embodiment is to use an integrated or discrete pulse converter mechanism that effectively adjusts the timing of the sensor’s pulses for each configuration change. The sensor position shift can be accounted for by a sensor shifting software that effectively repositions the sensor’s effective position by changing the timing of the sensing signal. Software can accommodate the system and can effectively produce the ideal“virtual” position of alternate force expansion sensor configurations. While a hall sensor has been referenced in this example, any number of mechanisms can be used as a magnetic angle sensor. One such signal converter that can be used to manage this process is a ZOH (Zero Order Hold) which can be part of an isolated discrete circuit element, or it can be fully integrated into the system.

In implementations, a hybrid model can be employed in which there is the use of both physical sensors (e.g., Hall sensors) along with a sensor-less observer. The system might use the Hall sensors to determine rotor position in one“electric gear” and use a sensor-less observer in another electric gear. As well, both can be used in the same electric gear depending upon the current operating state.

With the use of force expansion technology, the motor becomes what is effectively an entirely new machine, with unique attributes for machine properties like inductance, resistance, and impedance. The machine ID selected by the drive for optimal performance may be less than ideal unless drive characteristics are optimized as well. The drive software and hardware of the machine may be altered with a configuration change so as to optimized for the new machine characteristics. While advanced motor control software can improve performance, when the motor is reconfigured, the opportunity for improving performance is far greater given the machine is literally a new machine where the motor drive benefits from optimizing for the new motor configuration’s ID parameters (i.e. resistance, inductance, voltage, motor velocity constants, etc.).

The changes to software to account for the new motor coil design of the configuration can offer materials benefits, however the drive may as well optimize for an entirely different commutation strategy. As an example, the drive may switch between 6- step/trapezoidal commutation, and field-oriented control/space vector (FOC). Given the highly dynamic nature of a reconfigurable rotating electric machine, the ability to change commutation strategies on the fly can provide unique benefits. There are situations where given a coil reconfiguration, one of these drive strategies will outperform the other. Other waveforms may be produced by the drive to best accommodate the rotating electric machines reconfigured state, and in some cases unique waveforms. An ideal drive waveform matches that of the back electromotive force (EMF) of the motor.

More sophisticated drives are able to provide greater control and that control may be used to assist in a process where the rotor position feedback can be used to properly time the reintroduction of power is such a way as to ensure the drive and motor waveforms are aligned. Certain system are more capable than others. For example, if the drive has a“free-wheeling” mode it can be used to assist in improving the process.

For higher power systems with more sophisticated drive architectures, such as field oriented control, there may be accurate rotor position sensing and data feedback that can be used to“align” the waveforms of the drive and the

motor/generator. These more capable control architectures can be modified to receive accurate rotor position information which in turn can be used to provide a highly controlled process where the current is reapplied to the motor at the exact instant where the phase angles of the motor and the drive are aligned. When this is accomplished, the transients are significantly minimized.

While this proposed technique may provide a solution for more sophisticated systems, the less complex and less capable drives may not be capable of employing timing required for waveform alignment. The less expensive drives, such as 6-Step / trapezoidal drives, often use cheap sensor-less observers for determining commutation timing. They rely on the back EMF waveform of the motor to establish commutation timing, but these observers are not ideal in many situations, and do not work well at all speeds. Without accurate rotor position feedback (e.g., Flail sensors, encoders, resolvers, etc.) many systems are simply not able to be controlled as is required for the“phase alignment” solution to work. Referring to Figure 25, in implementations, the performing of a coil configuration change, i.e. , a“switching event,” may include a process by which the system releases the throttle before it disconnects power to the motor. Then, the system performs the coil switching to achieve a specified new configuration. When that is complete, the system then ramps up the power to the motor. This process helps to ensure a predictable switching event without unwanted transients that might cause damage to the system, or that may negatively impact an application (such as to create an undesirable torque perturbation).

Figure 25 presents a plot of drive current (in relative units) during a transient prevention process for a switching event. The time interval ti is the“release” band during which drive current is decreased from its operational value to zero. The time interval t2 is the“dead-band” during which the drive current is at zero. The time interval t3 is the“ramp” band during which the drive current is increased from zero back to its operational value. The power release (ti) and ramping (t3) time intervals are determined based upon the specific system and its operational characteristics (e.g., drive, switching interface, and motor). The timing for these processes may also be optimized based upon the operating state of the machine. Machine response times may vary given loading conditions and the slope of the ramp may be optimized accordingly.

Once the power is sufficiently removed from the motor, the switching event occurs, and windings are reconfigured to enable the intended configuration state, i.e.,“electrical gear.” This may be accomplished through a network of mechanical or semiconductor switches (e.g., relays, TRIACS, MOSFET pairs, or other switching architectures). At some point during the dead-band, where power has been removed from the rotating electric machine, the throttle reference signal is updated for the new configuration. When the system is ready to reengage the power to the motor the power is gradually ramped up again to help ensure a smooth transition that helps prevent unwanted effects, e.g., transient currents. In implementations, the electrical power applied to the machine may or may not the same as for a previous electrical gear - given the new coil configuration. In implementations, the electrical power characteristic applied to the machine (i.e., applied voltage and/or current) may differ for the new coil configuration. Thus, the electrical power characteristic ramps up to a new speed/throttle level based on the new selected motor configuration.

The“throttle release” and“throttle ramp” process can be implemented in any number of ways depending upon the type of drive and how it uses the signal data to effect changes in its output to the motor. The drive must fully respond to the throttle release change before the dead band is initiated and then the system must wait until the final coil configuration is properly connected before ramping the drive back on. Similarly, the throttle ramp can also be implemented by an incremental throttle/speed signal up to the desired level for the newly configured electrical gear.

Figures 26A and 26B present a diagram of a process for performing a switching event which includes a transient prevention process, which may be referred to as a“throttle release and ramp” transient suppression switching technique. As explained in further detail below, the algorithm triggers a switching event based upon a state in which the controller determines that an alternative coil configuration would produce more desirable operations than the current configuration. The system

determines what action to take based on, e.g., a preference for higher torque, speed, or efficiency.

When the control system determines a coil reconfiguration should be executed, this process is carried out to ensure proper coil switching operations while minimizing undesirable transients. It should be noted that while the example depicted uses speed as the variable used to determine a switching event, various other variables may be taken into consideration in the algorithm. For example, if efficiency is the desired criterion, the controller will access data to determine when the current configuration provides lower efficiency than an alternate configuration available. If this is the case, the system will trigger a switching event to transition to the more efficient configuration.

In this example, a speed feedback signal (2605) is fed to the controller where the system will perform a speed analysis (2610) to determine when it is timely to engage an alternative machine configuration (2615). If the criterion (e.g., speed) is met, and a configuration change is indicated, the throttle release (2620) begins and gradually reduces the power being fed to the motor. The system then determines whether sufficient current has been removed from the motor (2625) before engaging in the next part of the process (the diagram states“all current removed” but, in implementations, the decision may be based on a specified current level which is a relatively small non- zero value). If this requirement is met, the control will engage in the dead-band routine (2630). At the initialization of the dead-band routine, the switches used for configuring the machine coils are switched off. If all switches are confirmed to be off (2635), the process continues and gate signals will be applied to specified switches, thereby establishing the next coil topology configuration (2640). Next, the system ensures that all switches are ready for current (2645), i.e. , appropriately configured for the specified topology configuration. Once confirmed, the dead-band routine ends (2650) and the system then ramps the power back up in the motor (2655), i.e., performs a“throttle ramp,” to the appropriate operating state, maintaining the operating speed of the previous configuration.

As discussed above, the switching event process is designed to prevent the elements that create the transients through ensuring there is no substantive current running in the electric machine during the switching event. This is accomplished through the gradual ramping down of the power to the motor. There are other processes that can assist in ensuring a smooth switching event - either independently or by

augmenting the“release and ramp” switching. For example, the system may further reduce the undesired effects through employing precise event timing so as to create alignment between the waveforms of the drive and of the motor.

While techniques such as throttle release and ramp model help smooth switching event transitions, they may not be necessary in certain situations. Some applications might avoid the power release and ramping cycle and allow the transient to be produced by the system. Examples of where this may make sense are low power applications, where transients are minimized as a result, and less sophisticated drives architectures. In such a case, a system can remove power abruptly and use various circuit elements to deal with the inductive flyback created when the magnetic fields around the coils collapse (e.g., flyback diodes, snubber circuits, etc.).

The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.

The foregoing detailed description has set forth various implementations of the devices and/or processes via the use of block diagrams, schematics, and examples. Insofar as such block diagrams, schematics, and examples contain one or more functions and/or operations, it will be understood by those skilled in the art that each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Those of skill in the art will recognize that many of the methods or algorithms set out herein may employ additional acts, may omit some acts, and/or may execute acts in a different order than specified. The various implementations described above can be combined to provide further implementations.

These and other changes can be made to the implementations in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific implementations disclosed in the specification and the claims, but should be construed to include all possible implementations along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.