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Title:
ELECTRIC CHARGING SYSTEM AND METHOD
Document Type and Number:
WIPO Patent Application WO/2015/086745
Kind Code:
A1
Abstract:
The invention provides an electric vehicle charging system and method dynamically responding to real time safety measurements to protect the user, the vehicle, and the grid network.

Inventors:
JORDAN, Noel (LoughshinnySkerries, Co. Dublin, IE)
SAFRONOV, Sergiy (LoughshinnySkerries, Co. Dublin, IE)
Application Number:
EP2014/077379
Publication Date:
June 18, 2015
Filing Date:
December 11, 2014
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ECOSYNRG LTD (3 Ballykea, LoughshinnySkerries, Co. Dublin, IE)
International Classes:
B60L11/18
Domestic Patent References:
WO2013149076A12013-10-03
WO1995034932A11995-12-21
Foreign References:
US5659240A1997-08-19
US20130100982A12013-04-25
CN102412606A2012-04-11
EP2309617A12011-04-13
US20130278271A12013-10-24
US20120212235A12012-08-23
Other References:
None
Attorney, Agent or Firm:
LUCEY, Michael (Purdylucey Intellectual Property, 6-7 Harcourt TerraceDublin, 2, IE)
Download PDF:
Claims:
Claims

1. A charger system for charging a vehicle, said system is connected to a mains power supply and comprising a module for monitoring the continuity of a ground conductor path coming from the power supply, passing through a charging station, extending on to the vehicle being charged and returning to the charging station.

2. The charger system of claim 1 comprising a monitoring module for continuously monitoring the electrical continuity of a protective conductor extending from the power supply to the charging station, on to the vehicle and returning to the charging station.

3. The charger system of claim 2 wherein if the monitoring module detects a loss of electrical continuity of the protective conductor, the electrical supply circuit to the vehicle shall be opened by the charging station and the charging station is configured to report a problem to a user.

4. The charger system of any preceding claim comprising a grid frequency measurement module configured with a frequency response algorithm to control the charger in response to high or low frequency events in the power supply grid.

5. The charger system of any preceding claim comprising a grid voltage measurement module configured with a demand response algorithm to control the charger in response to high or low power demand events in the power supply grid at a local or macro level.

6. The charger system of claim 5 wherein voltage measurements obtained from the voltage measurement module are analysed to verify correct cable sizes are installed in the charger system by monitoring voltage variations for various load conditions.

7. The charger system of any preceding claim comprising at least one current sensor configured to make one or more current measurements.

8. The charger system of any preceding claim comprising a measuring module for measuring one or more electrical 'loads' within a building being monitored and/or controlled by the charging station and adapted to avoid exceeding the electrical capacity of the power supply, while at the same time ensuring maximum allowable current draw by the vehicle being charged. 9. The charger system of any preceding claim wherein data obtained from Real time phase angle measurements, voltage measurements and current measurements are processed by a processor to calculate at least one of Power Factor, Real Power, Reactive Power, and Apparent Power.

10. The charger system of any preceding claim comprising a module for real time temperature measurements measured by at least two independent sensors and means for allowing the charging station react to limit the permissible current drawn by the vehicle so as to avoid exceeding the cable rating of cables used to supply current to the vehicle.

11. The charger system of any preceding claim means for generating a customer profile from said data measurements and reporting the data to a server and storing it locally on an external memory for subsequent analysis.

12. The charger system of any preceding claim comprising a predictive maintenance module for monitoring the performance of the charging station from said data measurements and identifying faults or predict potential faults in performance in the system in real time.

13. A method of charging a vehicle connected to a mains power supply and comprising the steps of monitoring the continuity of a ground conductor path coming from the power supply, passing through a charging station, extending on to the vehicle being charged and returning to the charging station

14. A computer program comprising program instructions for causing a computer to perform the method of claim 13.

Description:
Title

Electric Charging System and Method

Field

The invention relates to relate to the field of electric charging of a device; and more specifically, to an electric vehicle charging station.

Background

Electric charging devices are well known for charging a device from the mains electricity grid.

Due to increasing popularity of electric vehicles more vehicle charging stations now exist on the grid posing problems to electricity supplier companies as they increase demand on the grid. In addition it is known that existing charger systems are not very efficient or adaptive for the end user.

It is therefore an object to provide an improved charging system and method.

Summary

According to the invention there is provided, as set out in the appended claims, a charger system for charging a vehicle, said system is connected to a mains power supply and comprising a module for monitoring the continuity of a ground conductor path coming from the power supply, passing through a charging station, extending on to the vehicle being charged and returning to the charging station.

The invention provides an electric vehicle charging station dynamically responding to 1. Real time safety measurements to protect the user, the vehicle, and the grid network. These safety measurements and algorithms include

a. Continuously monitoring the presence of the ground wire extending from the supply panel to the charging station, extending on to the electric vehicle and back to the charging station.

b. Checking for contactor welding in accordance with standards c. Verifying correct cable rating used to connect the charging station by monitoring voltage variations for various load conditions.

d. Responding to high low voltage alerts

e. Measuring ambient temperature and taking into account cable current carrying capacity variations due to temperature

f. Measuring current flow to premises and vehicle and responding to overload conditions faster than fuses or mcb's.

2. Real time grid frequency measurement allowing enhanced frequency response and firm frequency response algorithms to control the charger in response to high or low frequency events in the grid

3. Real time grid voltage measurements allowing demand response to high or low power demand events in the local utility substation or transformer network.

4. Real time current measurements from one or more current monitors to avoid exceeding the electrical capacity of the Service Panel supply, the rated supply of the dedicated EVSE circuit or premises circuits, while at the same time giving due consideration to the maximum allowable current draw by the electric vehicle.

5. Real time phase angle measurement

6. Responsive to external commands received from, for example, the back office server, the vehicle management interface software, or mobile phone texts or apps. In one embodiment there is provided a monitoring module for continuously monitoring the electrical continuity of a protective conductor extending from the power supply to the charging station, on to the vehicle and returning to the charging station.

In one embodiment if the monitoring module detects a loss of electrical continuity of the protective conductor, the electrical supply circuit to the vehicle shall be opened by the charging station and the charging station is configured to report a problem to a user.

In one embodiment there is provided a grid frequency measurement module configured with a frequency response algorithm to control the charger in response to high or low frequency events in the power supply grid.

In one embodiment there is provided a grid voltage measurement module configured with a demand response algorithm to control the charger in response to high or low power demand events in the power supply grid at a local or macro level. In one embodiment voltage measurements obtained from the voltage measurement module are analysed to verify correct cable sizes are installed in the charger system by monitoring voltage variations for various load conditions.

In one embodiment there is provided at least one current sensor configured to make one or more current measurements.

In one embodiment there is provided a measuring module for measuring one or more electrical 'loads' within a building being monitored and/or controlled by the charging station and adapted to avoid exceeding the electrical capacity of the power supply, while at the same time ensuring maximum allowable current draw by the vehicle being charged. In one embodiment data obtained from Real time phase angle measurements, voltage measurements and current measurements are processed by a processor to calculate at least one of Power Factor, Real Power, Reactive Power, and Apparent Power.

In one embodiment there is provided a module for real time temperature measurements measured by at least two independent sensors and means for allowing the charging station react to limit the permissible current drawn by the vehicle so as to avoid exceeding the cable rating of cables used to supply current to the vehicle. In one embodiment there is provided means for generating a customer profile from said data measurements and reporting the data to a server and storing it locally on an external memory for subsequent analysis.

In one embodiment there is provided a predictive maintenance module for monitoring the performance of the charging station from said data measurements and identifying faults or predict potential faults in performance in the system in real time.

In another embodiment there is provided a method of charging a vehicle connected to a mains power supply and comprising the steps of monitoring the continuity of a ground conductor path coming from the power supply, passing through a charging station, extending on to the vehicle being charged and returning to the charging station. In one embodiment there is provided a charger system for charging a vehicle, said system is connected to a mains power supply and comprising a module for monitoring the continuity of a ground conductor path coming from the power supply, passing through a charging station, extending on to the vehicle being charged and returning to the charging station.

There is also provided a computer program comprising program instructions for causing a computer program to carry out the above method which may be embodied on a record medium, carrier signal or read-only memory.

Brief Description of the Drawings

The invention will be more clearly understood from the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawings and document titled 'Outline Description', in which:-

Fig. 1 illustrates a general architecture of an electricity supply grid showing a house housing a charging system according to one embodiment;

Fig. 2 shows one aspect of the system where the frequency of the grid being measured continuously in real time;

Fig 3 shows how the voltage of the grid being measured continuously in real time;

Fig 4 illustrates how the current drawn through electrical circuits of the location can be monitored in real time

Fig 5 illustrates how ambient temperature is measured continuously using two independent sensors;

Fig. 6 is a block diagram that illustrates a more detailed view of the charging station according to one embodiment of the invention;

Fig. 7 is a flow diagram illustrating exemplary operations for MVPMS performed by the charging station according to one embodiment of the invention;

Fig. 8 and Fig. 9 outline how the process to check 'continuity of ground wire' works, according to one embodiment of the invention; Fig. 10 illustrates how the ground is monitored according to one embodiment; Fig. 11 illustrates how the time delay is measured and the phase angle calculated according to one embodiment of the invention;

Fig. 12 illustrates how EVSE, System, and Device parameters are measured continuously, amongst other parameters, according to one embodiment of the invention; and

Fig. 13 & 14 illustrate a number of flow charts illustrating operation.

Detailed Description of the Drawings

The invention relates generally to an electricity transfer system based on a multivariate power management system, hereafter referred to as MVPMS, and particularly to an electricity transfer system for controlling an electric vehicle charging station and methods of providing, using, and supporting the same. MVPMS provides a method and apparatus for an electrical vehicle charging system embodying electrical safety management, utility grid management, power management, load management, and time management encapsulated in one management system as described above. In one embodiment of the invention, the electrical vehicle charging system includes a charging station that is installed in a location that is used to charge electric vehicles and a number of monitors that measure, monitor, control and/or react to:

1. The continuity of the ground wire coming from the electrical service panel, passing through the charging station, extending on to the vehicle being charged and returning to the charging station

2. the frequency of the grid being measured continuously in real time

3. the voltage of the grid being measured continuously in real time

4. the current drawn through electrical circuits of the location

5. the phase angle between the voltage measured and the current measured

6. the power factor as calculated

7. the real power as calculated or measured

8. the apparent power as calculated or measured

9. the reactive power as calculated or measured 10. the internal temperature being measured in real time

11. external commands received

An electric vehicle charging station that is installed in a suitable location is coupled with a main circuit breaker in an electrical service panel (not shown), as illustrated generally in Figure 1. The charging station includes as a minimum a charging point connection that couples an electric vehicle to a set of service drop power lines that provide electricity from a power grid to the location; a current control device, coupled to control the amount of electric current that can be drawn from the set of service drop power lines by the electric vehicle through the charging point connection; additional current measurement devices coupled to monitor the amount of electric current that is drawn from the set of service drop power lines by apparatus or electrical appliances in the premises; a receiver to receive energy readings from one or more current monitors that indicate an amount of current is being drawn from the set of service drop power lines; and a set of control modules to cause the current control device, as controlled by MVPMS, to control the amount of current that can be drawn by the electric vehicle through the charging point connection to avoid tripping the main circuit breaker, or adversely affecting the grid while maximising the current transfer to the vehicle. The charging station can be coupled with a charging station network server (hereinafter "server"). The charging station may be coupled with the server over a Wide Area Network (WAN) such as the Internet, over a Local Area Network (LAN), and/or through a charging station gateway and/or payment station The location can include other devices or appliances which consume energy, i.e. that draw electric current from the service drop power line(s).

The location also includes the charging station, which is used to charge electric vehicles (e.g., the electric vehicle as shown). In this embodiment, the charging station is capable of charging electric vehicles at a faster rate than charging electric vehicles through a standard outlet. The charging station can be wired to a separate circuit breaker, rated above the maximum rating of the charging station but lower than the rated ampacity of the supply cable, through the electrical circuit. However, it should be understood that in some embodiments of the invention the charging station is plugged into an electrical receptacle which is wired to the breaker.

The charging station can include a set of one or more modules comprising the main board, coupled with a set of one or more modules comprising a Power board, coupled with a set of one or more modules comprising the PF board, coupled with one or more modules comprising the communications modules, coupled with various other devices comprising the charging point connection. The charging point connection provides an attachment for electric vehicles to a source of electric current and allows electric vehicles to be charged (assuming that the charging point connection is energized, which will be described in greater detail later herein).

FIG. 2 illustrates an electric vehicle that is attached to the charging point connection by the charging cord. The main board, which is coupled with the charging point connection, controls the amount of current that can be drawn by an electric vehicle using a pulse width modulated signal through the charging point connection.

The charging station controls the amount of current that can be drawn by an electric vehicle (e.g., the electric vehicle through the charging point connection is based on:

1. the received energy readings to avoid exceeding the electrical capacity of the location and tripping the main circuit breaker

2. The measured voltage at the location to avoid exceeding the rating, both upper and lower limits, of the local transformer or sub-station.

3. The measured frequency at the location of the grid as part of frequency response algorithms

4. the current drawn through electrical circuits of the location

5. the phase angle between the voltage measured and the current measured

6. the power factor as calculated

7. the real power as calculated or measured

8. the apparent power as calculated or measured 9. the reactive power as calculated or measured.

In one embodiment, the charging station determines whether to vary the current drawn, de-energize or energize the charging point connection based on the received readings (MVPMS). For example, in one embodiment, the charging station de-energizes the charging point connection in response to determining that the frequency measured as indicated by the received reading (MVPMS) exceeds a threshold (which may be configurable by the vehicle owner and/or administrative personnel). For example in another embodiment, the charging point connection is de-energized when the charging station receives the readings (MVPMS) and determines that measured voltage level is below a threshold (which may be configurable by the vehicle owner and/or administrative personnel). In another embodiment the charging station energises the charging point connection when the charging station determines the frequency measured as indicated by the received reading (MVPMS) exceeds a threshold (which may be configurable by the vehicle owner and/or administrative personnel).

Fig 2 shows one aspect of the system showing the frequency of the grid can be measured continuously in real time. A voltage divider circuit is used to reduce the voltage from 230vac to less than 0.32vrms. The signal is inputted to PIC microcontroller. An ADC circuit converts the signal(C) to digital form and software algorithms filter out any unwanted noise. Two consecutive positive portions of the digital waveform are analysed and stored temporarily. A point on the first positive rising waveform is selected and the time of the measurement is taken. The corresponding point on the next positive rising waveform is obtained from the stored measurements and the time difference (T) between both points is calculated. The frequency (f) is then calculated from the formula VT =/.

Fig 3 shows how the voltage of the grid being measured continuously in real time. A voltage divider circuit can be used to reduce the voltage from 230vac to less than 0.32vrms. The signal is inputted to a Peripheral Interface (PIC) microcontroller. An ADC circuit converts the signal(C) to digital form and software algorithms filter out any unwanted noise. Two consecutive positive portions of the digital waveform are analysed and stored temporarily. Based on the samples stored the peak voltage amplitude is obtained and then converted into a rms value. If the supply repeatedly exceeds 254V then the Electricity supplier is legally required to take steps to rectify the situation. Rapid steps are required if the mains is a seriously high value, for example in excess of 255V as there is an increased risk of fire at thes high values. Low voltages should also be avoided as in some appliances motors can burn out due to low voltage operation.

Fig 4 illustrates how the current drawn through electrical circuits of the location can be monitored in real time. A current transformer circuit is used to sense the waveform. The signal(D) is inputted to a PIC microcontroller. The PIC microcontroller turns on/off multiple stages in the current transformer circuit to allow accurate measurements to be carried out over the range OA to 80A. Two consecutive positive portions of the inputted waveform are analysed and stored temporarily. Based on the samples stored and which stages of the current transformer circuit is turned on the peak current amplitude is obtained and then converted into rms value. Measuring the current load (A*+A**) at all times allows for the maximum power transfer to the vehicle while also protecting the vehicle, the building cable infrastructure as software can react much quicker than other solutions.

Fig 5 illustrates how a phase angle between the voltage measured and the current are measured. Two signals (C, D) are inputted to a PIC microcontroller. An ADC circuit converts the signals to digital form and software algorithms filter out any unwanted noise. The time at which both signals pass their respective zero point crossings is stored. The time difference At is calculated. The phase angle is then calculated from the equation Ψ = 360° . / .At where the frequency / has previously been calculated.

Power Factor True Power Apparent Power

1. the power factor as calculated

2, the real power as calculated or measured

3 the apparent power as calculated or measured

4, the reactive power as calculated or measured

5 the internal temperature being measured in real

6 external commands received FIG. 6 is a block diagram that illustrates a more detailed view of the charging station according to one embodiment of the invention. As illustrated in FIG. 6, in addition to the charging point connection, the main board and power board includes STM processor, PIC processor, RGB circuitry, Lock circuitry, PWM circuitry, power circuitry, ext memory circuitry, buzzer circuitry, int memory circuirty, neutral weld circuitry, ground continuity circuitry, uart (x3) circuitry, iButton circuitry, spi circuitry, RTC and backup battery circuitry, contactor(x2) control circuitry, current measurement circuitry, temperature measurement circuitry, wired internet circuitry, key switch input circuitry, circuitry for ext meter, circuitry for ext timer, circuitry for monitoring contactor (x2) open or closed, RS 485 circuitry for communicating with keypads, led's, RFID, barcode reader. The PF board includes frequency measurement circuitry, voltage measurement circuitry, phase angle measurement circuitry, current measurement circuitry. In addition the charging station also includes the receiver (wired and/or wireless), the user interface, the data store, and the display unit (which is optional).

The receiver may be a wireless receiver (e.g., ZigBee, Bluetooth, WiFi, Infrared, GPRS/GSM, CDMA, etc.) or a wired receiver (e.g., Ethernet, PLC (Power Line Communication), etc.). It should be under- stood that the charging station may include multiple receivers of different types. In some embodiments, the charging station also includes a transmitter (e.g., to send notification message(s) to the user(s) of the charging station, vehicle management software, a server which stores all events, states, commands, etc in addition to being stored on ext memory within the charging station).

The ext memory and or the server stores data related to the charging station including data related to charging sessions (e.g., for each session a session start time, session end time, amount of current drawn, etc) as well as data related to electrical load management (e.g., data in received energy readings, present potential current draw, etc.), as well as data related to the grid (e.g. frequency, voltage, phase angle, power factor, P power, S power, Q power, including kWhrs or equivalents for each power type, both single and three phase). The MVPMS defines the triggers and actions the charging station takes when controlling the amount of current that can be drawn by an electric vehicle through the charging point connection (e.g., whether to energize or de-energize the charging point connection, whether to adjust the maximum amount of electric current that can be drawn through the charging point connection (and the amount of that adjustment), whether to inform the electric vehicle that the maximum available current of the charging station has changed, etc.). The display unit can be either a traditional display such as an 1CD screen, or a PC, or a Smart phone. The display unit, which is optional, displays all or part of the information stored in the form of screens or messages to the users of the charging station. For example, the display unit can display status messages including that charging has commenced, charging has completed, charging has been suspended, error message(s), etc.

The display (e.g., a graphical user interface, a telnet interface, an interface accessible through a browser through a computing device (e.g., laptop, workstation, smart phone, etc.), etc.) allows users of the charging station to configure the charging station including MVPMS configurations. For example, the users may use the user interface to configure the MVPMS policy.

The charging station may also include an external energy meter (optional) which measures the amount of current flowing on the circuit through the current control device and the charging point connection. The readings from the energy meter may be stored in the data store, and may be accessible by the user(s) of the charging station (e.g., through the user interfaces).

The charging station may also include an external timer device, in addition to its internal timer, (optional) which allows a schedule to be arranged for charging the electric vehicle.

FIG. 7 is a flow diagram illustrating exemplary operations for MVPMS performed by the charging station according to one embodiment of the invention.

At block 7_a, the Charging Station with Multi Variate Power Management System(s) receives a continuous stream of data from an array of monitoring sensors. As no vehicle is connected the charging station is in 'stand-by' mode. Every 15 minutes (programmable) it stores all reading in the external memory and sends the data to the back office server. It is also recording and transmitting internal diagnostic readings and safety readings. This data allows for enhanced maintenance response to users of the system. Flow moves from block 7_a to block 7_b.

At block 7_b, the consumer connects the electric vehicle to the charging station. The charging station detects the vehicle being plugged in and records and transmits this information. Flow moves to block 7_c. The charging station begins a process whereby it checks what rules, if any, are to be followed and based on these rules the charging station behaves in a specified way. Fig 7 contains one example of specified rules. At block 7-c, the MVPMS rules may cause the current control device to de-energize the charging point connection to prevent the electric vehicle from drawing current through the charging point connection. It should be understood that de-energizing the charging point connection may interrupt a charging session currently in progress or may prevent a charging session from being established since de-energizing the charging point connection essentially turns off the electric supply at the charging point connection. In response to de-energizing the charging point connection, the charging station transmits a charging station de-energized notification message to the server and records this event in external memory also. The charging station and or the server may also send a notification message which may be a text message, an email, or other message type, which alerts the user(s) that the charging station is de-energized. At block 7_c, the MVPM system continuously receives a stream of data and based on the 'decision tree' determines what the next course of action will be.

At block 7_c, when allowed by MVPMS the control module causes the current control device to energize the charging point connection to allow the electric vehicle to draw current through the charging point connection. Energizing the charging point connection essentially turns on the electric supply at the charging point connection. In some embodiments, responsive to energizing the charging point connection, the charging station transmits a charging station energized notification message to the user(s) of the charging station. The charging station and or the server may also send a notification message which may be a text message, an email, or other message type, which alerts the user(s) that the charging station is now energised (i.e., the electric vehicle is presently drawing current through the charging station), the charging station informs the electric vehicle that charging is presently allowed and at what rate to draw current. If at any time the current being drawn exceed a specified level above the agreed rate the charging station will interrupt the charging session and register a fault, and the electric vehicle ceases drawing current. This essentially suspends the charging session. For example, if the SAE J1772 standard is used, on-board charging circuitry (e.g., control pilot circuitry) of the charging station modulates the pilot duty cycle to indicate that charging is presently not allowed and the electric vehicle ceases charging.

Voltage divider circuits are used to reduce the voltage from 230vac to less than 0.425vrms respectively. Both signals are inputted separately to the PIC microcontroller. An ADC circuit converts one signal(A) to digital form and software algorithms filter out any unwanted noise. The second signal(B) passes through an optoisolator, is amplified and then smoothed out before being inputted to both the PIC microcontroller and the STM microcontroller.

The continuity of the ground wire coming from the electrical service panel, passing through the charging station, extending on to the vehicle being charged and returning to the charging station is continuously monitored. Flowcharts in Figure 8 and Figure 9 outline how the process to check 'continuity of ground wire' works. One part of the process begins with the PIC microcontroller analysing the positive sections of signal (A) waveform as shown in Figure 8. When the wave crosses the zero point line a trigger is generated which commences the measuring sequence. If no triggers are generated the PIC microcontroller sends a 'fail' signal to a microprocessor. The STM microprocessor in less than 140ms de-energises the 'safety' contactor, if energised, which opens the circuit to the electric vehicle. The charging station is now in a status 'timer mode charging prohibited - sub mode Eth Fail'. The maximum amplitude of the recurring positive sections are measured and compared to a threshold value. If the measured amplitude falls below this threshold a counter is incremented by one. If the measured amplitude is above the threshold value the counter is decremented by one. The counter cannot have a value below zero. If the counter exceeds a pre- set limit the PIC microcontroller sends a 'fail' signal to the STM controller. The STM microprocessor in less than 140ms de-energises the 'safety' contactor, if energised, which opens the circuit to the electric vehicle. In the event the PIC microcontroller generates a 'fail' signal to the STM the PIC microcontroller then analyses the input signal(B). A series of samples of signal(B) are aggregated and compared to a threshold value. If the aggregated value is less than the threshold value then the PIC microcontroller opens a relay which disconnects the 230v signal from the PCB for a period of 10 minutes. The PIC microcontroller closes the relay after the ten minutes has elapsed and testing recommences with all timers and counters reset to zero. This 'ten' minute cycle can be repeated a number of times before a 'fault' condition is decided upon by the STM microcontroller if it has not received a 'pass' signal from the PIC microcontroller.

The STM microprocessor analyses the input from the PIC microcontroller and input signal(B) as shown in Figure 9. Upon receiving a 'fail' signal from the PIC microcontroller the STM microprocessor in less than a preset time, for examplel40ms, de-energises the 'safety' contactor, if energised, which opens the circuit to the electric vehicle. It will be appreciated that any type of suitable processor and controller can be used. The STM microcontroller now begins a cyclical process which can last up to 120minutes, as an example, after which if both inputs, PIC microcontroller and signal(B), are indicating discontinuity of the ground wire then the STM microcontroller places the charging station into a 'fault' condition and de-energises the 'power' contactor, if energised. Charging is no longer possible until the integrity of the ground wire is restored and the charging station is powered off and then on again. If during a 120 minute period the STM receives a 'pass' signal from the PIC microcontroller and signal(B) is above the required threshold then the charging station returns to its previous status it was in before entering 'timer mode charging prohibited - sub mode Eth Fail' status. It will be appreciated that one of more current monitors measure current flowing on the electrical circuits. Thus, the current monitors measure the amount of current that is being drawn on the service drop power line(s) through the electrical circuits. In some embodiments the current monitors are inductive couplers (or other current transformers) that are attached to the circuits, however in other embodiments the current monitors may be other devices that are suitable for monitoring current on an electrical circuit. In some embodiments, the current monitors are located within the electrical service panel and the charging station. The current monitors are located on the main supply circuit in the location and within the charging station as shown.

The current monitors transmit the energy readings respectively to the charging station. An energy reading that is received by the charging station indicates to the charging station that an amount of current is being drawn on the service drop power lines inclusive of any current that is being drawn through the charging point connection. In some embodiments current monitors can be placed on all or any sub-circuits within the electrical sub panel, each energy reading includes a specific amount of current draw as monitored by the corresponding current monitor, while in other embodiments the current monitors can be device/appliance specific, each energy reading includes a specific amount of current draw as monitored by the corresponding current monitor. In some embodiments, each energy reading includes a current monitor identifier that identifies the current monitor providing the energy reading.

In some embodiments the energy readings are transmitted wirelessly (e.g., through ZigBee, Bluetooth, WiFi, Infrared, GPRS/ GSM, CDMA, etc.) to the charging station, while in other embodiments the energy readings are transmitted to the charging station through a wired connection (e.g., Ethernet, RS485, PLC (Power Line Communication), etc.).

Referring again to Figure 1, and Figures 10 to 12 in detail. The frequency 'f is a universal parameter throughout a typical supply grid indicated generally by the reference numerals 100/200/300/400/500/600 which is used as an indicator of the 'health' of the Grid. The frequency f 601 of the Grid is measured 303/607 and the charging station reacts in accordance with customer/user/utility modifiable rules within a customer/user/utility specified time frame, usually less than 1 second, and store the measurement both locally and on back-office servers for analysis.

A problem for Utilities is that if the frequency falls below 48.8 cycles per second, the grid is in serious trouble because there is not enough supply to meet demand. In fact, below this level, towns would start to black out as an emergency procedure to keep the generators spinning. National Grids are responsible for contracting short term generating provision to cover demand prediction errors and sudden failures at power stations. Frequency Response Reserve acts to keep the system AC frequency within 1% of 50Hz, except in exceptional circumstances.

The charging station of the present invention react within agreed time frames to reduce the load on the Grid by interrupting the charging process/modifying the charging rate to agreed rules, thereby helping to offset the loss of generating capacity or demand prediction errors.

Another problem for Utilities is that at present, any excess electricity production, such as from wind turbines, is lost because National Grid controllers are forced to switch off supply from some energy sources to avoid the AC frequency rising beyond legal limits.

The charging station of the present invention react within agreed time frames to increase the load on the Grid by commencing the charging process/modifying the charging rate to agreed rules, helping to use up the extra generation capacity. In addition, using two way communications, the customer/user/utility can interrupt/modify/schedule responses to Frequency Variations. This response is known as 'localised dynamic demand control' whereby the electricity consumption of our charging stations is managed is in a way that it responds to the state, or 'health' of, the grid.

The voltage V is a parameter which is used as an indicator of the 'health' of the local Grid Supply 301/400/500/602/700. It is affected by any load turned on/off within any of the premises supplied by the local distribution system 301. The voltage V602 of the local Grid Supply, such as a distribution system supplying a small number of dwellings or a business, is measured 303/607 and the charging station reacts in accordance with customer/user/utility modifiable rules within a customer/user/utility specified time frame, and store the measurement both locally and on back-office servers for analysis.

Another problem for Customer/User/Utility - Low- voltage Problems the burden on local distribution circuits such as transformers and cables, which are the critical links in distribution systems, will increase significantly under PEV loads. The 'cluster effect' of PEV's in a local distribution system could cause the transformer to burn out or reduce its working lifetime.

Other problems include relays not closing or opening which affects controls, mechanical functions, powering-up sequences and so on. Finally, low voltages may cause some older type appliances with motors to burn out, particularly fridges and freezers

Electronic and electrical devices are designed to operate at a certain maximum supply voltage, and considerable damage can be caused by voltage that is higher than that for which the devices are rated. The charging station of the present invention can react within agreed time frames to increase/decrease/modify the load on the local Grid by commencing the charging process/modifying the charging rate/interrupting the charging process to agreed rules.

The current A, current drawn by all electrical devices connected to the premises Grid Supply, is measured 303 and the current , current drawn by the electric vehicle, is measured 607 and stores the measurements both locally and on back-office servers for analysis.

From both measurements the charging station can modify in real time the maximum permissible current that can be drawn by the electric vehicle so as not to overload the premises power (fuse board) board rating and trip the main incoming MCB. The charging station reacts in accordance with customer/user/utility modifiable rules within a customer/user/utility specified time frame, and stores the measurement both locally and on back-office servers for analysis.

Additionally from the measurements at 303/607 it is known if cable ratings of any premises circuit 604/606 is being exceeded and alerts can be generated. The charging station reacts in accordance with customer/user/utility modifiable rules within a customer/user/utility specified time frame, and stores the measurement both locally and on back-office servers for analysis. The charging station can control other devices to interrupt any overloaded circuit which has such a device fitted and the charging station reacts in accordance with customer/user/utility modifiable rules within a customer/user/utility specified time frame, and stores the measurement both locally and on back-office servers for analysis.

Additionally from the measurements at 303/607 the phase angle is measured and true, reactive, and apparent power are calculated. The charging station reacts in accordance with customer/user/utility modifiable rules within a customer/user/utility specified time frame, and stores the measurement both locally and on back-office servers for analysis. The charging station can control other devices to interrupt any overloaded circuit which has such a device fitted and the charging station reacts in accordance with customer/user/utility modifiable rules within a customer/user/utility specified time frame, and stores the measurement both locally and on back-office servers for analysis.

The temperature t, within the charging station 607, can be measured by two independent sensors and the charging station reacts to limit, in accordance with customer/user/utility modifiable rules within a customer/user/utility specified time frame, the permissible current drawn by the electric vehicle so as to avoid exceeding the cable rating of cables used to supply current to the electric vehicle and stores the measurement both locally and on back-office servers for analysis. The continuity of the Ground circuit E100/E101/E102/E103/E104 as outlined in Fig. 10 above is continuously monitored as per standards and the charging station reacts by interrupting the charging process/not allowing the charging process to commence if this continuity is broken or interrupted in a manner as outlined elsewhere in Figures 13 and 14. The charging station stores these measurements and status changes both locally and on back-office servers for analysis.

Two signals(C, D) are inputted to PIC microcontroller. An ADC circuit converts the signals to digital form and software algorithms filter out any unwanted noise.

The time at which both signals pass their respective zero point crossings is stored. The time difference At is calculated. The phase angle is then calculated from the equation Ψ = 360° . / . At where the frequency / has previously been calculated. It will be appreciated that the charging station measures/monitors over 65 parameters, a sample of which is illustrated above.

The system reports each event to a remote server in addition to storing the data on external memory. An event can be a change of state, such as 'standby' to 'cable connected', external command received, or an event such as 'out of limit/spec'. The station reports over 65 separate pieces of information in one embodiment.

The system is capable of receiving external commands such as 'stop', start, modify pwm, scheduling times, etc

These features allow for both predictive maintenance and enhanced customer care. It takes maintenance standards to a whole new level. It means the customer/user/utility are aware, in most cases, of the existence of a problem in real time, thus allowing proactive customer care. With Predictive Maintenance it will be possible to carry out not only the necessary routine tasks, but also focused and detailed proactive tasks, preserving the value of the charging station throughout its lifetime. These features also allow monitoring of the long term performance of the charging station and its components.

In one embodiment there is provided an internal device, or devices, to measure the temperature within the charging station. Software algorithms monitor the internal temperature of the charging station and decide whether to commence, moderate, or cease the charging process All the above software algorithms are fully integrated into the charging process. The charging station is capable of bi-directional communication, using WiFi, GPRS, PLC, RS485, UART, or wired connection. It reports each event to a remote server. An event can be a change of state, such as 'standby' to 'cable connected', external command received, or an event such as 'out of limit/spec'. The station reports over 65 separate pieces of information. It is capable of receiving external commands such as 'stop', start, modify pwm, scheduling times, etc The charging station continually reports to the server the status of device components such as contactors, FCT lock, key switches, buttons, backup battery, etc. The charging station continually measures and reports to the server the value of system parameters such as PWM state, PWM , PWM value, cable connected size, etc

These features allow for both predictive maintenance and enhanced customer care. It takes maintenance standards to a whole new level. It means the system is aware, in most cases, of the existence of a problem in real time, thus providing superior customer care. With Predictive Maintenance it is possible to carry out not only the necessary routine tasks, but also focused and detailed proactive tasks, preserving the value of equipment throughout its lifetime. These features also allows the system to monitor the long term performance of the charging station and its components.

The charging station continually monitors the continuity of the ground conductor, both the incoming ground conductor from the premises and the continuity of the ground conductor to the electric vehicle and the return path to the charging station. The ability to monitor the incoming ground is a unique feature.

The charging station continually checks for a 'weld' on the power contactor and will not energise the 'safety' contactor in the event of a 'weld' being detected. An electric vehicle charging station, which includes a battery-backed Real Time Clock. An external memory to store all events of the charging process, all internal diagnostic measurements, and all external commands received. An electric vehicle charging station, which has fleet management capabilities such as scheduling, variable load control, load management. In one embodiment, the charging station is activated using an RFID tag, a two-way wireless communication device having an associated memory, a barcode, a QR code, and combinations thereof.

In another embodiment, the charging station is activated using an iButton, a microchip housed in a stainless steel casing, an associated reader to supply power, capable of receiving and sending data. In another embodiment, the charging station is activated using a keypad. In another embodiment, the charging station is activated using a key switch. In another embodiment, the charging station is activated using a RF module. In another embodiment, the charging station is activated using a barcode reader. It will be appreciated that in the context of the present invention that the term 'vehicle' is used and should be interpreted broadly to cover any device that requires to be charged from a mains supply power network and should be interpreted as such.

The embodiments in the invention described with reference to the drawings comprise a computer apparatus and/or processes performed in a computer apparatus. However, the invention also extends to computer programs, particularly computer programs stored on or in a carrier adapted to bring the invention into practice. The program may be in the form of source code, object code, or a code intermediate source and object code, such as in partially compiled form or in any other form suitable for use in the implementation of the method according to the invention. The carrier may comprise a storage medium such as ROM, e.g. CD ROM, or magnetic recording medium, e.g. a floppy disk or hard disk. The carrier may be an electrical or optical signal which may be transmitted via an electrical or an optical cable or by radio or other means. In the specification the terms "comprise, comprises, comprised and comprising" or any variation thereof and the terms include, includes, included and including" or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation and vice versa. The invention is not limited to the embodiments hereinbefore described but may be varied in both construction and detail.