Power supply switching method and device, storage medium and electronic equipment

Abstract

The invention discloses a power supply switching method and device, a storage medium and electronic equipment, and relates to the technical field of mining, and the method comprises the steps: firstly obtaining a current waveform and a current direction of a standby power supply; determining a fault detection result of the standby power supply based on the current waveform and the current direction; and finally, if the fault detection result is that the standby power supply does not have the internal fault, the differential protection state of the standby power supply is adjusted to be a locking state, and the standby power supply is switched to supply power. Through the mode, the fault detection result of the standby power supply can be determined by detecting the current waveform and the current direction of the standby power supply, that is, whether a fault exists in the standby power supply or not is judged, and if it is detected that the standby power supply does not have the fault, the differential protection state of the standby power supply is adjusted to be the locking state. When the standby power supply is switched, the standby power supply continues to be switched for power supply, differential protection maloperation during standby power supply switching is reduced, and the stability of the system is improved.

Description

Technical Field

[0001] The present application relates to the field of power supply detection technology, and in particular to a power supply switching method, device, storage medium and electronic device. Background Art

[0002] In the power system, when the main power supply fails, it is necessary to quickly switch to the backup power supply. Testing the backup power supply helps to ensure the reliability and stability of the power system.

[0003] At present, the relevant technology usually adopts the fast-cut parallel switching method. The main power supply and the backup power supply are connected in parallel for a short time. During the switching, it is easy to cause the backup power supply differential protection to malfunction. The lack of effective detection of the backup power supply affects the stable operation of the system and may also cause unnecessary power outages and equipment damage. Summary of the invention

[0004] In view of this, the present application provides a power switching method, device, storage medium and electronic device, the main purpose of which is to improve the technical problems of the quick-cut parallel switching method commonly used in related technologies, in which the main power supply and the backup power supply are briefly connected in parallel, which easily causes the backup power supply differential protection to malfunction during switching, and lacks effective detection of the backup power supply, affecting the stable operation of the system, and may also cause unnecessary power outages and equipment damage.

[0005] In a first aspect, the present application provides a power switching method, comprising:

[0006] Obtain the current waveform and current direction of the backup power supply;

[0007] Determining a fault detection result of the backup power supply based on the current waveform and the current direction;

[0008] If the fault detection result shows that the backup power supply has no internal fault, the differential protection state of the backup power supply is adjusted to a locked state, and the backup power supply is switched.

[0009] In a second aspect, the present application provides a power switching device, comprising:

[0010] An acquisition module is configured to acquire a current waveform and a current direction of the backup power supply;

[0011] a determination module configured to determine a fault detection result of the backup power supply based on the current waveform and the current direction;

[0012] The switching module is configured to adjust the differential protection state of the backup power supply to a locked state and switch the backup power supply if the fault detection result shows that the backup power supply has no internal fault.

[0013] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the power switching method described in the first aspect.

[0014] In a fourth aspect, the present application provides an electronic device, comprising a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, wherein the processor implements the power switching method described in the first aspect when executing the computer program.

[0015] By means of the above technical scheme, the present application provides a power switching method, device, storage medium and electronic device, firstly obtaining the current waveform and current direction of the backup power supply; then determining the fault detection result of the backup power supply based on the current waveform and current direction, and finally if the fault detection result is that the backup power supply has no internal fault, adjusting the differential protection state of the backup power supply to a locked state, and switching the backup power supply. Compared with the current prior art, the present application can determine the fault detection result of the backup power supply by detecting the current waveform and current direction of the backup power supply, that is, judging whether there is a fault inside the backup power supply, and if it is detected that the backup power supply has no fault, adjusting the differential protection state of the backup power supply to a locked state, and continuing to switch the backup power supply, reducing the differential protection misoperation when switching the backup power supply, thereby reducing unnecessary power outages and equipment damage, and improving the stability of the system.

[0016] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] Figure 1 A schematic diagram of a flow chart of a power switching method provided in an embodiment of the present application is shown;

[0020] Figure 2 A schematic diagram of a flow chart of a power switching method provided in an embodiment of the present application is shown;

[0021] Figure 3 A schematic diagram of an example process provided by an embodiment of the present application is shown;

[0022] Figure 4 A schematic structural diagram of a power switching device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0023] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0024] In order to improve the technical problem that the fast-cut parallel switching method is usually adopted in the related technology, the main power supply and the backup power supply are briefly connected in parallel, which may easily cause the backup power supply differential protection to malfunction during switching, lack effective detection of the backup power supply, affect the stable operation of the system, and may also cause unnecessary power outages and equipment damage. This embodiment provides a power switching method, such as Figure 1 As shown, the method includes:

[0025] Step 101: Obtain the current waveform and current direction of the backup power supply.

[0026] In some embodiments, when a failure or abnormality is detected in the main power supply (main transformer), power can be continued to be provided by the start-up and standby transformer (Start-Up and Standby Transformer, SUS) as a backup power supply. The start-up and standby transformer in the power supply system is a key equipment for ensuring the reliability and stability of the power system. It is usually put into use during the failure or maintenance of the main transformer to ensure the continuity of power supply.

[0027] In a specific application scenario, the voltage and current of the main power supply can be monitored first to detect whether it has a fault. In response to detecting a main power failure, the system can quickly switch to the backup power supply through a quick-cut or automatic backup device. During the startup of the backup power supply, the current waveform and current direction of the backup power supply can be monitored in real time to perform a fault analysis of the backup power supply.

[0028] Exemplarily, a high-speed sampler (such as a high-speed data acquisition card) and a current transformer (CT) can be used to detect high and low voltage current waveforms, and a high-precision current transformer and a direction detection device can be used to detect the direction of high and low voltage currents, and the collected data can be stored in a computer or other storage device for subsequent analysis.

[0029] Step 102: Determine a fault detection result of the backup power supply based on the current waveform and current direction.

[0030] Among them, the fault types of the backup power supply may include but are not limited to: internal faults (such as equipment short circuit, insulation damage, etc.), external faults (such as line short circuit, etc.), transient processes (such as excitation inrush current, DC component, high-frequency component), etc.

[0031] In some embodiments, the current waveform and current direction on both sides of the high and low voltage of the backup power supply can be detected, and the fault type can be determined based on the detection results to generate a fault detection result. For example, second harmonic detection, transient characteristic analysis, current direction consistency and other tests can be performed to determine whether an internal fault occurs in the backup power supply, and the differential protection state of the backup power supply can be adjusted based on the fault detection results to improve the accuracy of fault detection, thereby reducing differential protection misoperation and ensuring the stability of the power system.

[0032] Step 103: If the fault detection result shows that the backup power supply has no internal fault, the differential protection state of the backup power supply is adjusted to a locked state, and the backup power supply is switched.

[0033] In some embodiments, if the fault detection result indicates that the backup power supply has no internal fault, the differential protection is locked and the power supply is switched to the backup power supply through a quick switching or backup automatic switching device, thereby preventing false operation of the differential protection during the switching process and ensuring the safe and stable operation of the power system.

[0034] Compared with the current existing technology, this embodiment first obtains the current waveform and current direction of the backup power supply; then based on the current waveform and current direction, determines the fault detection result of the backup power supply; finally, if the fault detection result is that the backup power supply has no internal fault, the differential protection state of the backup power supply is adjusted to a locked state, and the backup power supply is switched. In this way, this embodiment can determine the fault detection result of the backup power supply by detecting the current waveform and current direction of the backup power supply, that is, judge whether there is a fault inside the backup power supply. If it is detected that the backup power supply has not failed, the differential protection state of the backup power supply is adjusted to a locked state, and the backup power supply is continued to be switched, thereby reducing the differential protection malfunction when switching the backup power supply, thereby reducing unnecessary power outages and equipment damage, and improving the stability of the system.

[0035] In order to further illustrate the specific implementation process of the method of this embodiment, this embodiment provides the following Figure 2 The specific method shown includes:

[0036] Step 201: Obtain the current waveform and current direction of the backup power supply.

[0037] Optionally, step 201 may specifically include: using a high-speed sampler to collect the current waveform of the backup power supply at the current moment; calling a current transformer to detect the current direction of the backup power supply at the current moment.

[0038] In a specific application scenario, current transformers can be installed on the high and low voltage sides of the backup power supply to collect current signals, and the current signals output by the current transformers can be connected to high-speed samplers for real-time sampling. For example, a high-speed sampler can be used to collect current waveform data at a high sampling rate (e.g., 10kHz) to improve the accuracy of waveform acquisition. Accordingly, high-precision current transformers can be installed on the high and low voltage sides of the backup power supply, and a direction detection device (such as a directional relay) can be used to detect the direction of the current, and the information on the current direction can be recorded to facilitate subsequent fault detection and analysis of the backup power supply and improve the accuracy of the current signal.

[0039] Step 202: Obtain a current waveform detection result of the backup power supply according to the current waveform at the current moment; and / or obtain a current direction detection result of the backup power supply according to the current direction at the current moment.

[0040] Optionally, based on the current waveform at the current moment, it is determined whether the current waveforms on both sides of the high and low voltage of the backup power supply are consistent, and a current waveform detection result is generated; and / or, based on the current direction at the current moment, it is determined whether the current directions on both sides of the high and low voltage of the backup power supply are consistent, and a current direction detection result is generated. Then, based on the current waveform detection result and / or the current direction detection result, it can be determined whether the backup power supply has an internal fault.

[0041] Optionally, based on the current waveform at the current moment, the current waveform detection result of the backup power supply is obtained, which may specifically include: obtaining the current waveform of the backup power supply under normal use; comparing the current waveform of the backup power supply under normal use with the current waveform at the current moment, and obtaining the current waveform detection result.

[0042] Optionally, the current waveform of the backup power supply in normal use is compared with the current waveform at the current moment to obtain a current waveform detection result, which may specifically include: obtaining the waveform similarity between the current waveform of the backup power supply in normal use and the current waveform at the current moment; determining the current waveform detection result based on the waveform similarity and the waveform similarity threshold.

[0043] In some embodiments, the similarity of the current waveforms before and after the backup power supply fails can be compared to determine whether it is an internal fault, and a waveform similarity threshold is set. When the waveform similarity exceeds the waveform similarity threshold, it can be determined that the current waveform detection result is that the current waveform at the current moment is not similar to the current waveform under normal use; when the waveform similarity does not exceed the waveform similarity threshold, it can be determined that the current waveform detection result is that the current waveform at the current moment is similar to the current waveform under normal use.

[0044] In specific application scenarios, methods such as correlation coefficient and Euclidean distance can be used to calculate the waveform similarity of the current waveform of the backup power supply at different times. For example, a suitable correlation coefficient threshold is set, such as 0.9, and a suitable Euclidean distance threshold is set, such as 10. If the correlation coefficient is greater than 0.9 or the Euclidean distance is less than 10, it is considered that the waveform similarity is high and the backup power supply has no internal fault; if the correlation coefficient is less than 0.9 or the Euclidean distance is greater than 10, it is considered that the waveform similarity is low and the backup power supply has an internal fault.

[0045] Optionally, based on the current direction at the current moment, the current direction detection result of the backup power supply is obtained, which may specifically include: obtaining the current direction of the backup power supply under normal use; comparing the current direction of the backup power supply under normal use with the current direction at the current moment, and obtaining the current direction detection result.

[0046] Step 203: Determine a fault detection result of the backup power supply based on the current waveform detection result and / or the current direction detection result.

[0047] In some embodiments, when the backup power supply is fault-free, the current directions and current waveforms corresponding to the high and low voltage sides usually show a certain consistency. For example, if the current directions of the high and low voltage sides are consistent and the waveform similarity is high, it can be determined that the backup power supply is fault-free; if the current directions of the high and low voltage sides are inconsistent or the waveform similarity is low, it can be determined that the backup power supply may have an internal fault or external interference.

[0048] Optionally, step 203 may specifically include: obtaining a current waveform of the backup power supply in a normal use state; comparing the current waveform of the backup power supply in a normal use state with the current waveform at the current moment, and obtaining a current waveform detection result.

[0049] In some embodiments, the problem of distinguishing the start-up of the standby transformer longitudinal differential protection can be mainly addressed when the working power supply and the standby power supply of the same system are short-term paralleled due to the fast switching. Since the DC component and the second harmonic component are large in the initial switching stage, the second harmonic can be locked when it is large; the waveforms on both sides of the high and low voltage are relatively basically the same, and software for comparing the waveforms on both sides can be added to the judgment criteria. If the current directions on both sides of the transformer are consistent with the current directions on both sides before the fault, and the current waveforms on both sides are basically similar, it is determined that there is no internal fault in the transformer, and the protection outlet is locked. If a fault occurs inside the transformer, the current direction on one side will change.

[0050] For example, Figure 3As shown, taking the standby transformer as an example, the differential protection can be started first, and it is detected that the switch position on the low-voltage side of the transformer has changed. For example, a jump occurs on a low-voltage side, and the circuit is in an abnormal state. At this time, both sides of the fault initially contain DC components, and the current directions of the high and low voltage sides at the current moment can be obtained. The current directions of the high and low voltage sides at the current moment are compared with those before the fault (before the jump). If the waveform detection result of the comparison point is that the current waveforms of the high and low voltage sides are relatively consistent, it can be determined that the fault is not internal to the transformer, and the differential protection is locked, thereby avoiding the false operation of the standby transformer longitudinal differential protection when the plant power supplies of different power supply systems are switched in parallel, thereby preventing the plant power supply from failing to switch due to a fault in the generator set at this time, which endangers the safe shutdown of the generator set.

[0051] Optionally, the second harmonic component in the differential current of the backup power supply can be detected to determine whether the longitudinal differential protection is caused by a transient process. Specifically, the second harmonic component in the differential current can be detected using Fast Fourier Transform (FFT), and a suitable second harmonic component threshold can be set. When the detected second harmonic component exceeds the threshold, the differential protection is locked.

[0052] Further optionally, the differential protection judgment can be made according to the rise time of the transient current and the amplitude of the transient current. Specifically, appropriate rise time and amplitude thresholds can be set first, and when the detected rise time and amplitude meet the thresholds, the differential protection is locked.

[0053] As a possible implementation method, the rise time and amplitude of the current waveform can be analyzed, the similarity of the current waveform can be compared, and the consistency of the current direction can be detected, and the thresholds of the second harmonic component, waveform similarity and transient characteristics can be set. For example, when the second harmonic component is detected to exceed the set threshold, it can be determined as a transient process; when the rise time and amplitude of the current waveform meet the transient characteristics, it can be determined as a transient process; when the similarity of the current waveform exceeds the set threshold, it can be determined as a transient process; when the current direction is consistent, it can be determined as a transient process.

[0054] In this way, based on the real-time detection of the current waveform and current direction of the high and low voltage sides of the backup power supply at the current moment, and comparing them with the preset threshold, the cause of the differential protection can be further analyzed, and it can be effectively determined whether the backup power supply has an internal fault. If no internal fault is detected, the differential protection state of the backup power supply is adjusted to the locked state, and the backup power supply is switched to prevent the malfunction of the differential protection during the switching process, so as to ensure the safe and stable operation of the power system.

[0055] Step 204: If the fault detection result shows that the backup power supply has no internal fault, the differential protection state of the backup power supply is adjusted to a locked state, and the backup power supply is switched.

[0056] In some embodiments, if it is determined that there is no internal fault in the backup power supply based on the current waveform and / or current direction, the differential protection can be locked and the backup power supply can continue to be used, thereby adding some criteria for starting the backup transformer longitudinal differential protection, reducing the possibility of false operation of the backup transformer longitudinal differential protection due to insufficient consideration of the working conditions on site, and thereby improving the stability of the generator set.

[0057] In some embodiments, during the process of locking the differential protection, a delay setting can be performed, and the delay time can be set, for example, tens of milliseconds to hundreds of milliseconds. During the delay time, the differential protection is locked. After the differential protection is locked, the power supply is switched to the backup power supply through a quick switching or backup automatic switching device. After waiting for the delay time to end, the differential protection is re-enabled.

[0058] Optionally, the method of this embodiment may further specifically include: if the fault detection result is that an internal fault occurs in the backup power supply, adjusting the differential protection state of the backup power supply to a start state, and stopping switching the backup power supply.

[0059] In some embodiments, if it is determined that there is a fault inside the backup power supply based on the current waveform and / or current direction, the differential protection can be started, and the differential protection state of the backup power supply can be adjusted to the started state, and the backup power supply can be stopped. Other backup power supplies can be found and tested before supplying power, thereby ensuring power supply safety and preventing the backup power supply failure from affecting the normal use of other equipment and causing unnecessary losses.

[0060] In some embodiments, the protection device can be tested regularly to verify the reliability of the protection function, ensure that the protection device can operate correctly under various fault conditions, discover and solve potential problems of the protection device, avoid false operation or refusal to operate in actual operation, and thus ensure the normal operation of the equipment. Exemplarily, a dedicated relay protection tester can be used to simulate various fault conditions, record the results of each test in detail, including the action time and action value of the protection device, analyze the test data, and evaluate the performance and reliability of the protection device. Specifically, it is possible to verify whether the logical function of the protection device is correct, check whether the parameter settings of the protection device are correct, and perform verification, and establish a complete test and verification file for subsequent reference and analysis.

[0061] Compared with the prior art, the present embodiment can obtain the current waveform and current direction of the backup power supply under normal use, and determine the current waveform detection result by obtaining the waveform similarity between the current waveform of the backup power supply under normal use and the current waveform at the current moment, and comparing the waveform similarity with the waveform similarity threshold. It can also obtain the current direction detection result by comparing the current direction of the backup power supply under normal use and the current direction at the current moment, and determine the fault detection result of the backup power supply based on the current waveform detection result and / or the current direction detection result, thereby improving the accuracy of fault detection of the backup power supply, improving the differential protection judgment method in the process of starting the standby transformer, and avoiding the false operation of the longitudinal differential protection of the starting transformer when the plant power supplies of different power supply systems are switched in parallel, thereby preventing the plant power supply from being unable to switch due to a fault in the generator set at this time, endangering the safe shutdown of the generator set.

[0062] In specific application scenarios, such as when the 6kV plant common section of a thermal power plant is quickly switched in parallel, the generator set can be connected to the 500kV system, and the starting and standby transformer can be connected to the 220kV system. There is no connecting transformer between the 500kV system and the 220kV system in the plant. When the power supply from the starting and standby transformer is switched back to the plant power supply in the common section, due to the parallel connection of the quick switch, the working power supply and the standby power supply are briefly connected in parallel, and the switching causes the starting and standby transformer differential protection to malfunction. The internal recording report of the device can be retrieved to determine the differential protection status by judging whether the waveform shapes on the high and low voltage sides are consistent and whether the secondary harmonic braking (waveform identification) is completely braked. In this way, the criteria for the longitudinal differential protection of the starting and standby transformer are increased, which can effectively reduce the malfunction of the longitudinal differential protection, thereby improving the overall safety and stability of the power system.

[0063] Further, as Figure 1 and Figure 2 The specific implementation of the method shown in the embodiment provides a power switching device, such as Figure 4 As shown, the device includes: an acquisition module 31, a determination module 32, and a switching module 33.

[0064] An acquisition module 31 is configured to acquire a current waveform and a current direction of a backup power supply;

[0065] A determination module 32 is configured to determine a fault detection result of the backup power supply based on the current waveform and the current direction;

[0066] The switching module 33 is configured to adjust the differential protection state of the backup power supply to a locked state and switch the backup power supply to supply power if the fault detection result shows that the backup power supply has no internal fault.

[0067] In some examples of this embodiment, the acquisition module 31 is specifically configured to use a high-speed sampler to collect the current waveform of the backup power supply at the current moment; and call a current transformer to detect the current direction of the backup power supply at the current moment.

[0068] In some examples of this embodiment, the determination module 32 is specifically configured to obtain a current waveform detection result of the backup power supply based on the current waveform at the current moment; obtain a current direction detection result of the backup power supply based on the current direction at the current moment; and determine a fault detection result of the backup power supply based on the current waveform detection result and / or the current direction detection result.

[0069] In some examples of this embodiment, the acquisition module 31 is specifically configured to obtain the current waveform of the backup power supply under normal use; compare the current waveform of the backup power supply under normal use with the current waveform at the current moment, and obtain the current waveform detection result.

[0070] In some examples of this embodiment, the determination module 32 is specifically configured to obtain the waveform similarity between the current waveform under normal use of the backup power supply and the current waveform at the current moment; based on the waveform similarity and the waveform similarity threshold, determine the current waveform detection result.

[0071] In some examples of this embodiment, the acquisition module 31 is specifically configured to obtain the current direction of the backup power supply in normal use; compare the current direction of the backup power supply in normal use with the current direction at the current moment, and obtain the current direction detection result.

[0072] In some examples of this embodiment, the determination module 32 is further configured to adjust the differential protection state of the backup power supply to the start state and stop switching the backup power supply if the fault detection result is that the backup power supply has an internal fault.

[0073] It should be noted that for other corresponding descriptions of the functional units involved in the power switching device provided in this embodiment, reference can be made to Figure 1 and Figure 2 The corresponding description in will not be repeated here.

[0074] Based on the above Figure 1 and Figure 2 The method shown in the embodiment also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned Figure 1 and Figure 2 The method shown.

[0075] Based on this understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, USB flash drive, mobile hard disk, etc.), including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute the method of the implementation scenario of the present application.

[0076] Based on the above Figure 1 and Figure 2 The method shown, and Figure 4 In order to achieve the above-mentioned purpose, the embodiment of the present application also provides an electronic device, such as a personal computer, a server, which includes a storage medium and a processor; the storage medium is used to store a computer program; the processor is used to execute the computer program to achieve the above-mentioned Figure 1 and Figure 2 The method shown.

[0077] Optionally, the above-mentioned physical device may also include a user interface, a network interface, a camera, a radio frequency (RF) circuit, a sensor, an audio circuit, a WI-FI module, etc. The user interface may include a display, an input unit such as a keyboard, etc., and the optional user interface may also include a USB interface, a card reader interface, etc. The network interface may optionally include a standard wired interface, a wireless interface (such as a WI-FI interface), etc.

[0078] Those skilled in the art will appreciate that the above-mentioned physical device structure provided in this embodiment does not constitute a limitation on the physical device, and may include more or fewer components, or a combination of certain components, or different arrangements of components.

[0079] The storage medium may also include an operating system and a network communication module. The operating system is a program that manages the hardware and software resources of the above-mentioned physical device, and supports the operation of the information processing program and other software and / or programs. The network communication module is used to realize the communication between the components inside the storage medium, and the communication with other hardware and software in the information processing physical device.

[0080] Through the description of the above implementation methods, the technicians in this field can clearly understand that the present application can be implemented by means of software plus necessary general hardware platforms, or by hardware. By applying the technical solution of this embodiment, this embodiment obtains the current waveform and current direction of the standby power supply under normal use, obtains the waveform similarity between the current waveform under normal use of the standby power supply and the current waveform at the current moment, compares the waveform similarity with the waveform similarity threshold, and determines the current waveform detection result. It can also obtain the current direction detection result by comparing the current direction under normal use of the standby power supply with the current direction at the current moment, and determine the fault detection result of the standby power supply based on the current waveform detection result and / or the current direction detection result, thereby improving the accuracy of fault detection of the standby power supply, improving the differential protection judgment method in the process of starting the standby transformer, avoiding the misoperation of the longitudinal differential protection of the standby transformer when the plant power supplies of different power systems are switched in parallel, thereby preventing the plant power supply from being unable to be switched due to a fault in the generator set at this time, endangering the safe shutdown of the generator set, and increasing the judgment criteria of the longitudinal differential protection of the standby transformer, which can effectively reduce the misoperation of the longitudinal differential protection, thereby improving the overall safety and stability of the power system.

[0081] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0082] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features applied for herein.

Claims

1. A power switching method, characterized in that: include: Obtain the current waveform and current direction of the backup power supply; Determining a fault detection result of the backup power supply based on the current waveform and the current direction; If the fault detection result shows that the backup power supply has no internal fault, the differential protection state of the backup power supply is adjusted to a locked state, and the backup power supply is switched.

2. The method according to claim 1, characterized in that: The step of obtaining the current waveform and current direction of the backup power supply includes: Using a high-speed sampler to collect the current waveform of the backup power supply at the current moment; The current transformer is called to detect the current direction of the backup power supply at the current moment.

3. The method according to claim 2, characterized in that The determining of the fault detection result of the backup power supply based on the current waveform and the current direction includes: According to the current waveform at the current moment, obtaining the current waveform detection result of the backup power supply; and / or, According to the current direction at the current moment, obtaining a current direction detection result of the backup power supply; Based on the current waveform detection result and / or the current direction detection result, a fault detection result of the backup power supply is determined.

4. The method according to claim 3, characterized in that The step of obtaining the current waveform detection result of the backup power supply according to the current waveform at the current moment includes: Obtaining a current waveform of the backup power supply under normal use; The current waveform of the backup power supply in a normal use state is compared with the current waveform at the current moment to obtain the current waveform detection result.

5. The method according to claim 4, characterized in that The comparing the current waveform of the backup power supply in a normal use state with the current waveform at the current moment to obtain the current waveform detection result includes: Obtaining the waveform similarity between the current waveform of the backup power supply in a normal use state and the current waveform at the current moment; The current waveform detection result is determined based on the waveform similarity and the waveform similarity threshold.

6. The method according to claim 3, characterized in that The step of obtaining the current direction detection result of the backup power supply according to the current direction at the current moment includes: Obtaining the current direction of the backup power supply in a normal use state; The current direction of the backup power supply in a normal use state is compared with the current direction at the current moment to obtain the current direction detection result.

7. The method according to claim 1, characterized in that The method further comprises: If the fault detection result is that an internal fault occurs in the backup power supply, the differential protection state of the backup power supply is adjusted to a start state, and switching of the backup power supply is stopped.

8. A power switching device, characterized in that: include: An acquisition module is configured to acquire a current waveform and a current direction of the backup power supply; a determination module configured to determine a fault detection result of the backup power supply based on the current waveform and the current direction; The switching module is configured to adjust the differential protection state of the backup power supply to a locked state and switch the backup power supply if the fault detection result shows that the backup power supply has no internal fault.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. An electronic device comprising a storage medium, a processor, and a computer program stored in the storage medium and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

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