BREAKER

TECHNICAL FIELD

The present invention relates to the field of power systems, and in particular to a method and a device for correcting the closing time of a circuit breaker.

BACKGROUND ART

The circuit breaker is a very important device in power systems. For example, in the event of a fault, it can automatically control the cutoff of various power lines or equipment to ensure normal operations of the power system.

Specifically, the circuit-opening and circuit-closing coil of a circuit breaker is an important mechanism for the circuit breaker to break. It is very important to reasonably predict the next closing time of the circuit breaker. The closing time refers to the time interval from the moment when the closing circuit becomes electrified with the circuit breaker in the open position to the moment when all pole contacts are in contact.

Accurate determination of the closing time of a circuit breaker will reduce the impact on and disturbance of the power system.

SUMMARY OF THE INVENTION

In view of the above, the present invention proposes a method for correcting the closing time of a circuit breaker, the circuit breaker is located in a power system, and the method comprises ■ obtaining a definite reference closing time of the circuit breaker, the reference closing time being obtained when the circuit breaker is under a standard ambient temperature, a standard pressure and a standard control voltage; Obtaining current compensation factors corresponding to the circuit breaker, the compensation factors comprising at least two of: an ambient temperature of the circuit breaker, a voltage of the circuit breaker, and a control voltage of the circuit breaker! determining a correction time corresponding to a compensation factor based on the compensation factor! correcting the reference closing time based on all the correction time, to obtain an actual closing time.

In the method described above, optionally, determining a corresponding correction time based on a compensation factor comprises: determining the correction time corresponding to the compensation factor according to preset correction relationship information, the preset correction relationship information comprising a correspondence between the compensation factor and the correction time.

In the method described above, optionally, determining a corresponding correction time based on a compensation factor comprises: determining a corrected closing time corresponding to the compensation factor according to preset correction relationship information, the preset correction relationship information being determined by changing a third factor under a condition of a standard first factor and second factor, the third factor being one of the ambient temperature of the circuit breaker, the pressure of the circuit breaker and the control voltage of the circuit breaker, and the first factor and the second factor being the other two thereof!

Determining the correction time corresponding to the compensation factor based on the corrected closing time. In the method described above, optionally, correcting the reference closing time based on all the correction time to obtain an actual closing time comprises: determining the actual closing time of the circuit breaker based on a formula of:

TActuai T|vcl' Tcomp (temper) + Tcomp (pressure) + Tcomp (volt)

In the formula, TActuai is the actual closing time of the circuit breaker, TR _e f is the reference closing time of the circuit breaker, Tc _O m _P (temper) is the correction time corresponding to the ambient temperature, Tcomp (pressure) is the correction time corresponding to the pressure of the circuit breaker, and Tcomp (volt) is the correction time corresponding to the control voltage of the circuit breaker.

The present invention also provides a device for correcting the closing time of a circuit breaker, the circuit breaker is located in a power system, and the device comprises: a first obtaining unit, used for obtaining a definite reference closing time of the circuit breaker, the reference closing time being obtained when the circuit breaker is under a standard ambient temperature, a standard pressure and a standard control voltage; a second obtaining unit, used for obtaining current compensation factors corresponding to the circuit breaker, the compensation factors comprising at least two of: an ambient temperature of the circuit breaker, a voltage of the circuit breaker, and a control voltage of the circuit breaker; a determining unit, used for determining a correction time corresponding to a compensation factor based on the compensation factor; a correcting unit, used for correcting the reference closing time based on all the correction time, to obtain an actual closing time.

In the device described above, optionally, the determining unit is specifically used for: determining the correction time corresponding to the compensation factor according to preset correction relationship information, the preset correction relationship information comprising a correspondence between the compensation factor and the correction time.

In the device described above, optionally, the determining unit specifically comprises^ a first determining subunit, used for determining a corrected closing time corresponding to the compensation factor according to preset correction relationship information, the preset correction relationship information being determined by changing a third factor under a condition of a standard first factor and second factor, the third factor being one of the ambient temperature of the circuit breaker, the pressure of the circuit breaker and the control voltage of the circuit breaker, and the first factor and the second factor being the other two thereof; a second determining subunit, used for determining the correction time corresponding to the compensation factor based on the corrected closing time.

In the device described above, optionally, the correcting unit is specifically used for: determining the actual closing time of the circuit breaker based on a formula of:

T Actual TRO! + Tcomp (temper) + Tcomp (pressure) + Tcomp (volt)

In the formula, TActuai is the actual closing time of the circuit breaker, TR _e f is the reference closing time of the circuit breaker, Tcomp (temper) is the correction time corresponding to the ambient temperature, Tcomp (pressure) is the correction time corresponding to the pressure of the circuit breaker, and Tcomp (volt) is the correction time corresponding to the control voltage of the circuit breaker. The present invention further provides a device for correcting the closing time of a circuit breaker, comprising: at least one memory, used for storing an instruction! and at least one processor, used for executing the method for correcting the closing time of a circuit breaker according to any one of the paragraphs above according to the instruction stored in the memory.

The present invention further provides a readable storage medium, with a machine-readable instruction stored therein, which, when executed by a machine, causes the machine to execute the method for correcting the closing time of a circuit breaker according to any one of the paragraphs above.

It can be seen from the solution above that, in the present invention, the current compensation factors corresponding to a circuit breaker are obtained to obtain the corresponding correction time, and the correction time obtained is used to correct a reference closing time, to ultimately obtain a more accurate closing time with good timeliness as online correction of the closing time of the circuit breaker is made possible.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention are described in detail below with reference to the drawings, to give those skilled in the art a clearer understanding of the above-mentioned and other features and advantages of the present invention. In the figures:

Figure 1 is a schematic flowchart of the method for correcting the closing time of a circuit breaker according to one embodiment of the present invention.

Figure 2Ais a schematic flowchart of the method for correcting the closing time of a circuit breaker according to another embodiment of the present invention. Figure 2B is a schematic diagram of the correspondence between the ambient temperature and the actual closing time of a circuit breaker according to one embodiment of the present invention.

Figure 3 is a schematic flowchart of the method for correcting the closing time of a circuit breaker according to yet another embodiment of the present invention.

Figure 4Ais a schematic structural diagram of the device for correcting the closing time of a circuit breaker according to one embodiment of the present invention.

Figure 4B is a schematic structural diagram of the device for correcting the closing time of a circuit breaker according to another embodiment of the present invention.

SPECIFIC EMBODIMENTS

To clarify the objective, technical solution and advantages of the present invention, the present invention is explained in further detail below by way of embodiments.

Embodiment 1

This embodiment provides a method for correcting the closing time of a circuit breaker, and the executor of the method is a device for correcting the closing time of a circuit breaker. The device may be provided independently or integrated into various other devices, for example, a fast switching device or a relay protection device, depending on actual needs, which will not be detailed here. As shown in Figure 1, it is a schematic flowchart of the method for correcting the closing time of a circuit breaker according to this embodiment. The method comprises^

Step 101, obtaining a definite reference closing time of the circuit breaker.

The circuit breaker of this embodiment is located in a power system. The reference closing time here is a closing time that can be obtained in advance, it is obtained when the circuit breaker is under a standard ambient temperature, a standard pressure and a standard control voltage, and it is generally provided by the manufacturer. In other words, the reference closing time is the closing time of the circuit breaker before correction.

As an example, here, the standard ambient temperature is 20°C, the standard pressure is 26.5 MPa, and the standard control voltage is 220 V.

Step 102, obtaining current compensation factors corresponding to the circuit breaker, the compensation factors comprising at least two ofi the ambient temperature of the circuit breaker, the voltage of the circuit breaker, and the control voltage of the circuit breaker.

The inventors have found that there are actually factors that affect the closing time of a circuit breaker, for example, the ambient temperature of the circuit breaker, the pressure of the circuit breaker or the control voltage of the circuit breaker, which are all essential factors when the circuit breaker is working. Of these, the ambient temperature refers to the temperature of the current environment where the circuit breaker is located. As an example, the ambient temperature will change with the season. As another example, for a pneumatic circuit breaker, the pressure of the circuit breaker is the pressure of the gas in it, for example, the pressure of SF6, and for a hydraulic circuit breaker, the pressure of the circuit breaker is the pressure of the liquid in it, for example, oil pressure. As yet another example, the control voltage of the circuit breaker is the operating voltage of the circuit breaker, and the actual operating voltage will vary with the load.

Specifically, existing technologies may all be used for obtaining compensation factors. For example, the physical quantity of ambient temperature represents the degree of coldness or hotness of the environment, and the methods for obtaining it include the dry bulb temperature method, wet bulb temperature method, and black ball temperature method. The real-time pressure of a circuit breaker may be obtained by pressure sensors installed in the circuit breaker. The real-time control voltage of a circuit breaker may be obtained by voltage sensors connected to the circuit breaker.

Step 103, determining a correction time corresponding to a compensation factor based on the compensation factor.

For example, a corresponding correction time may be determined according to the current ambient temperature, the current pressure of the circuit breaker, or the current control voltage of the circuit breaker. The correction time is a factor used to correct the reference closing time.

As an example, the correction time corresponding to a compensation factor may be determined according to preset correction relationship information, and the preset correction relationship information comprises the correspondence between the compensation factor and the correction time. Compensation factors and correction time may be obtained through experiments in advance, and the relationship curve between the two may also be fitted through a limited number of experiments. The specifics may be set according to actual needs, and will not be detailed here. Step 104, correcting the reference closing time based on the correction time, to obtain an actual closing time.

For example, the reference closing time may be corrected based on the ratios of all the correction time or the sum thereof, thereby obtaining the actual closing time.

It should be noted that the method for correcting the closing time of a circuit breaker may be performed periodically, or in other words, real-time online correction of the closing time of a circuit breaker is realized.

According to this embodiment, the current compensation factors corresponding to a circuit breaker are obtained to obtain the corresponding correction time, and the correction time obtained is used to correct a reference closing time, to ultimately obtain a more accurate closing time with good timeliness as online correction of the closing time of the circuit breaker is made possible.

Embodiment 2

This embodiment will further describe the method for correcting the closing time of a circuit breaker.

As shown in Figure 2A, it is a schematic flowchart of the method for correcting the closing time of a circuit breaker according to this embodiment. The method comprises^

Step 201, obtaining a definite reference closing time of the circuit breaker, the reference closing time being obtained when the circuit breaker is under a standard ambient temperature, a standard pressure and a standard control voltage. The reference closing time here may be provided by the manufacturer, for example, in the product manual. The reference closing time is the closing time of the circuit breaker before correction.

Step 202, obtaining current compensation factors corresponding to the circuit breaker, the compensation factors comprising the ambient temperature of the circuit breaker, the voltage of the circuit breaker, and the control voltage of the circuit breaker.

The inventors have found through research that the ambient temperature, pressure and control voltage of the circuit breaker will affect the closing time, and thus it is necessary to correct the closing time of the circuit breaker based on the real-time ambient temperature, pressure and control voltage of the circuit breaker.

Specifically, the physical quantity of ambient temperature represents the degree of coldness and heat of the environment, and the methods for measuring it include the dry bulb temperature method, wet bulb temperature method, and black ball temperature method. The real-time pressure of a circuit breaker may be obtained by pressure sensors installed in the circuit breaker. The real-time control voltage of a circuit breaker may be obtained by voltage sensors connected to the circuit breaker.

Step 203, determining corresponding correction time based on the compensation factors.

In this embodiment, this step specifically comprises ■ determining a corrected closing time corresponding to a compensation factor according to preset correction relationship information, and determining the correction time corresponding to the compensation factor based on the corrected closing time.

The preset correction relationship information may be expressed in the form of a formula, or in the form of a curve.

As an example, the preset correction relationship information is determined by changing a third factor under the condition of a standard first factor and second factor, the third factor is one of the ambient temperature of the circuit breaker, the pressure of the circuit breaker and the control voltage of the circuit breaker, and the first factor and the second factor are the other two thereof. In other words, the relationship between the third factor and the corrected closing time is established by changing the third factor and obtaining the actual corrected closing time through measurement when the first factor and the second factor remain unchanged.

For example, the third factor is the ambient temperature, the first factor and the second factor are the standard pressure and the standard control voltage respectively. Firstly, refer to Figure 2B, which is a graph of the relationship between the ambient temperature and the corrected closing time, wherein the abscissa is the ambient temperature, in °C, and the ordinate is the corrected closing time, in ms. It can be seen from Figure 2B that the corrected closing time T Actual. temper decreases gradually as the ambient temperature Actual. temper increases. From Figure 2B, the correction time Tc _O m _P (temper) can be obtained, i.e., Tcomp (temper) T Actual. temper TRef, wherein TR _e f represents the reference closing time of the circuit breaker. In this way, the correction time corresponding to each ambient temperature can be obtained according to Figure 2B.

As another example, Table 1 shows the actual measured temperature and the corresponding corrected closing time in Figure 2B. The data in Table 1 can be obtained through commissioning in advance. In the case of an ambient temperature not listed in Table 1, the following formula (1) may be used to obtain the actual corrected closing time corresponding to the current ambient temperature, and to obtain the correction time Tc _O m _P (temper). Specifically, TR _e f is the reference closing time of the circuit breaker, being for example 47.2 ms in Figure 2B.

Table 1

F ormula (1) :

In the formula, actual, temper is the current ambient temperature obtained by measurement, temper 1 is an ambient temperature obtained in advance that is close to but lower than actual, temper, T _se ti is the corrected closing time corresponding to temper 1 obtained in advance, temper2 is an ambient temperature obtained in advance that is close to but lower than actual, temper, and T _se t2 is the corrected closing time corresponding to temper2 obtained in advance. For example, when actual, temper is -25°C, temperl is -40°C, T _se ti is 56.2ms, temper2 is -20°C, and T _se t2 is 49.8ms. The corrected closing time can be calculated as Tactuai.temper = 46.875 ms, and Tc _O m _P (temper) = 0.325 ms based on the formula above. Similarly, the correction time corresponding to each pressure can be obtained when the third factor is the pressure of the circuit breaker, and the correction time corresponding to each control voltage can be obtained when the third factor is the control voltage.

By obtaining the corrected closing time corresponding to a compensation factor, the correction time is further obtained, so that the obtained correction time is more accurate, and the final actual closing time is determined more accurately.

Step 204, determining the actual closing time of the circuit breaker based on the following formula- TActual ^— TRef + Tcomp (temper) + Tcomp (pressure) + Tcomp (volt) .

In the formula, TActual is the actual closing time of the circuit breaker, TR _e f is the reference closing time of the circuit breaker, Tcomp (temper) is the correction time corresponding to the ambient temperature, Tcomp (pressure) is the correction time corresponding to the pressure of the circuit breaker, and Tcomp (volt) is the correction time corresponding to the control voltage of the circuit breaker.

Here, the sum of three correction times is used to correct the reference closing time, which can not only ensure the accuracy of the final actual closing time, but also simplify the calculation and obtain the final result quickly.

In this embodiment, the effects of three compensation factors on the closing time of the circuit breaker are considered, and the reference closing time of the circuit breaker is corrected by these three compensation factors, thereby making the closing time of the circuit breaker more accurate.

Embodiment 3

This embodiment provides an application of the method for correcting the closing time of a circuit breaker described in the embodiments above in fast switching. The power system of many plants generally has two power sources, one power supply that is currently supplying power is used as the main power supply, and the other is used as the backup power supply. It is necessary to disconnect the main power supply in some circumstances, for example, in case of a failure of the main power supply. To ensure uninterrupted power supply, it is necessary to switch the power supply from the main power supply to the backup power supply as quickly as possible. In terms of the switching mode, fast switching devices may be classified as three types: series switching, parallel switching and simultaneous switching. In China, series switching is generally adopted, i.e., after the fast switching device receives the start signal, it firstly decides whether the circuit breaker of the main power supply is completely disconnected, then decides whether the backup power supply meets the closing conditions after the circuit breaker is completely disconnected, and selects the appropriate time to switch over to the backup power supply according to the closing conditions. Specifically, whether the backup power supply meets one of the closing conditions is determined based on the closing time of the circuit breaker. After the disconnection of the main power supply is detected, it is necessary to immediately determine the closing time of the current circuit breaker to decide whether the closing condition of the circuit breaker is met.

Specifically, the method for correcting the closing time of a circuit breaker of this embodiment comprises:

Step 301, obtaining a definite reference closing time of the circuit breaker, the reference closing time being obtained when the circuit breaker is under a standard ambient temperature, a standard pressure and a standard control voltage. This step is specifically consistent with the foregoing embodiment, and will not be repeated here.

Step 302, when it is detected that it is necessary to switch from the main power supply to the backup power supply, obtaining current compensation factors corresponding to the circuit breaker, the compensation factors comprising at least two ofi the ambient temperature of the circuit breaker, the voltage of the circuit breaker, and the control voltage of the circuit breaker.

There are many situations where it is detected that it is necessary to switch from the main power supply to the backup power supply. For example, it is detected that the main power supply is disconnected according to the position switch of the main power supply, and then it is necessary to switch to the backup power supply, or it is decided that the main power supply is disconnected according to the voltage drop on the bus connected to the main power supply, and then it is necessary to switch to the backup power supply. There are many options for the specific method, which may be selected according to actual needs.

The method for obtaining current compensation factors corresponding to the circuit breaker is consistent with the previous embodiment, and will not be repeated here.

Step 303, determining a correction time corresponding to a compensation factor based on the compensation factor.

This step is consistent with the foregoing embodiment, and will not be repeated here.

Step 304, correcting the reference closing time based on all the correction time, to obtain an actual closing time. This step is consistent with the foregoing embodiment, and will not be repeated here.

Step 305, deciding whether the closing condition is met based on the actual closing time.

Specifically, the phase angle difference and the frequency difference of the voltage between the power supply on the bus and the backup power supply at the time of closing can be determined based on the actual closing time to decide whether the closing condition is met.

The method for correcting the closing time of a circuit breaker according to this embodiment provides more accurate predictions of the phase difference and the frequency difference, thereby more accurately deciding whether the closing condition is met.

Embodiment 4

This embodiment provides a device for correcting the closing time of a circuit breaker, wherein the circuit breaker is located in a power system. The device for correcting the closing time of a circuit breaker is used to execute the method for correcting the closing time of a circuit breaker described above.

As shown in Figure 4A, it is a schematic structural diagram of the device for correcting the closing time of a circuit breaker according to this embodiment. The device for correcting the closing time of a circuit breaker comprises a first obtaining unit 401, a second obtaining unit 402, a determining unit 403 and a correcting unit 404. Of these, the first obtaining unit 401 is used for obtaining a definite reference closing time of the circuit breaker, the reference closing time being obtained when the circuit breaker is under a standard ambient temperature, a standard pressure and a standard control voltage! the second obtaining unit 402 is used for obtaining current compensation factors corresponding to the circuit breaker, the compensation factors comprising at least two of: an ambient temperature of the circuit breaker, a voltage of the circuit breaker, and a control voltage of the circuit breaker! the determining unit 403 is used for determining a correction time corresponding to a compensation factor based on the compensation factor! and the correcting unit 404 is used for correcting the reference closing time based on all the correction time, to obtain an actual closing time.

Optionally, the determining unit 403 is specifically used for: determining the correction time corresponding to a compensation factor according to preset correction relationship information, the preset correction relationship information comprising a correspondence between the compensation factor and the correction time.

Optionally, as shown in Figure 4B, the determining unit 403 specifically comprises a first determining subunit 4031 and a second determining subunit 4032, the first determining subunit 4031 is used for determining a corrected closing time corresponding to a compensation factor according to preset correction relationship information, the preset correction relationship information being determined by changing a third factor under the condition of a standard first factor and second factor, the third factor being one of the ambient temperature of the circuit breaker, the pressure of the circuit breaker and the control voltage of the circuit breaker, and the first factor and the second factor being the other two thereof, and the second determining subunit 4032 is used for determining the correction time corresponding to the compensation factor based on the corrected closing time. Optionally, the correcting unit 404 is specifically used for: determining the actual closing time of the circuit breaker based on a formula below:

T Actual Tl cl' + Tcomp (temper) + Tcomp (pressure) + Tcomp (volt) wherein TActuai is the actual closing time of the circuit breaker, TR _e f is the reference closing time of the circuit breaker, Tcomp (temper) is the correction time corresponding to the ambient temperature, Tcomp (pressure) is the correction time corresponding to the pressure of the circuit breaker, and Tcomp (volt) is the correction time corresponding to the control voltage of the circuit breaker.

The operating principles of each unit in this embodiment are the same as those in the above-described embodiments, which will not be further described herein.

According to this embodiment, the current compensation factors corresponding to a circuit breaker are obtained to obtain the corresponding correction time, and the correction time obtained is used to correct a reference closing time, to ultimately obtain a more accurate closing time with good timeliness as online correction of the closing time of the circuit breaker is made possible.

The present invention further provides a device for correcting the closing time of a circuit breaker, comprising at least one memory and at least one processor. Specifically, the memory is used to store an instruction. The processor is used for executing the method for correcting the closing time of a circuit breaker described in any one of the embodiments above according to the instruction stored in the memory.

An embodiment of the present invention further provides a readable storage medium. A machine-readable instruction is stored in the readable storage medium, and the machine-readable instruction, when executed by a machine, causes the machine to execute the method for correcting the closing time of a circuit breaker described in any one of the embodiments above.

The readable medium stores a machine-readable instruction that, when executed by a processor, causes the processor to execute any one of the above-described methods. Specifically, a system or apparatus equipped with a readable storage medium may be provided; software program code realizing a function of any one of the embodiments above is stored on the readable storage medium, and a computer or processor of the system or apparatus is caused to read and execute a machine-readable instruction stored in the readable storage medium.

In this case, the functions of any one of the above embodiments may be performed by a program code read from the readable medium, so a machine- readable code and a readable storage medium for storing machine-readable code constitute a part of the present invention.

Examples of readable storage media include floppy disks, hard disks, magnetooptical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD- RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards and ROM. Optionally, the program code may be downloaded from a server computer or a cloud via a communication network.

Those skilled in the art should understand that various changes in form and amendments may be made to the embodiments disclosed above without departing from the substance of the invention. Thus, the scope of protection of the present invention shall be defined by the attached claims.

It should be noted that not all steps and units in the above-described process flows and system structure diagrams are necessary, and some steps or units may be omitted according to actual needs. The sequence in which the steps are executed is not fixed, but may be adjusted as needed. The apparatus structure described in the above embodiments may be either a physical structure or a logical structure, which means that some units may be implemented by the same physical entity, or some units may be implemented by a plurality of physical entities separately or by some parts of a plurality of independent devices jointly. In the embodiments above, a hardware unit may be realized in a mechanical or an electrical manner. For example, a hardware unit or processor may comprise a permanently dedicated circuit or logic (for example, a specialized processor, FPGA, or ASIC) to complete corresponding operations. A hardware unit or processor may further comprise programmable logic or circuits (such as general- purpose processors or other programmable processors), which may be temporarily set by software to complete corresponding operations. Particular embodiments (mechanical, or dedicated permanent circuitry, or temporarily set circuitry) may be determined based on considerations of cost and time.

The embodiments above are merely preferred embodiments of the present invention, which are not intended to limit it. Any amendments, equivalent substitutions or improvements etc. made within the spirit and principles of the present invention shall be included in the scope of protection thereof.