Substation detection and automatic switching method, device, equipment and medium

Abstract

This invention discloses a substation synchronization detection and automatic transfer switch (ATS) method, relating to the field of new energy technology, to address the inapplicability of existing ATS schemes to distributed new energy access. The method includes the following steps: when the main power supply line fails to reclose on the grid side, the reclosing of the main power supply line circuit breaker is blocked; the electrical signals of the standby line and the corresponding bus II of the substation are detected; the output frequency is adjusted based on the voltage phase judgment result of bus II and the standby line; the phase difference between the standby line and bus II is continuously detected; when the phase difference meets the criterion, the circuit breaker at one end of the standby line is closed. This invention also discloses a substation synchronization detection and ATS device, electronic equipment, and computer storage medium. This invention uses the ATS device to detect the voltage signals of the standby line and the corresponding bus, and coordinates with the new energy device, thereby making the ATS suitable for distributed new energy systems.

Description

Technical Field

[0001] This invention relates to the field of distributed new energy technology, and more particularly to a method, apparatus, equipment, and medium for automatic switching of substations during synchronous operation and backup, applicable to distributed new energy access. Background Technology

[0002] To improve the reliability of power supply in power systems, substations are widely equipped with automatic transfer switch (ATS) devices, also known as standby automatic transfer devices. Specifically, when a fault occurs on the main power supply line of a substation, the circuit breakers on both sides open, initiating a reclosing phase. If reclosing fails, the ATS process begins. Current ATS schemes are designed for traditional radial power grids with single-end power supply. With the integration of distributed renewable energy sources, traditional ATS schemes often fail to operate promptly and correctly, are difficult to coordinate with relay protection and line reclosing, and are prone to generating large inrush voltages and currents when the standby line is activated. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a method for detecting automatic switching of synchronism in substations, which utilizes the signal of no-voltage failure detected by the automatic switching device to activate the automatic switching function and realize reclosing.

[0004] One of the objectives of this invention is achieved through the following technical solution:

[0005] A method for automatic switching of substation synchronization backup includes the following steps:

[0006] When a failure to reclose on the main power supply line is detected, the reclosing of the circuit breaker at one end of the main power supply line is blocked.

[0007] The automatic transfer switch is activated, and the relevant electrical quantity signals of the backup line and the corresponding bus II are detected. The relevant electrical quantity signals include: the voltage amplitude of the backup line and the corresponding bus II, the synchronous voltage amplitude of the backup line and the bus II, and the synchronous voltage phase difference.

[0008] When the voltage amplitude of the backup line meets the preset criteria, the difference in synchronous amplitude and frequency between the backup line and bus II is judged; otherwise, the circuit breaker at one end of the backup line is blocked and the process ends.

[0009] When the amplitude difference and phase difference between the backup line and bus II meet the preset criterion range, the phase difference is judged; otherwise, the circuit breaker of the new energy system is disconnected and the bus II is judged to be unvoltaged after a delay. When the unvoltage criterion is met, the circuit breaker at one end of the backup line is closed; otherwise, the circuit breaker at one end of the backup line is locked and the process ends.

[0010] When the synchronous phase difference criterion is not met, the phase difference between bus II and voltage and the phase difference between standby line voltage are judged; otherwise, the circuit breaker at one end of the standby line is closed directly.

[0011] Based on the judgment results of the voltage phase of bus II and the voltage phase of the backup line, adjust the output frequency of the new energy source;

[0012] Continue to monitor the phase difference between the backup line and bus II;

[0013] If the phase difference detected continues to meet the criteria, close the circuit breaker at one end of the backup line.

[0014] Furthermore, grid-side reclosing failures include:

[0015] If the main power supply line fails, the relay protection device will disconnect the circuit breaker at one end of the main power supply line.

[0016] The procedure for activating the circuit breaker at one end of the main power supply line to detect synchronization and reclosing includes: detecting whether there is voltage on the main power supply line; if there is voltage, closing the circuit breaker when the voltage on both sides is synchronized; otherwise, blocking reclosing, thus forming an islanded system between the new energy source and the load.

[0017] Furthermore, the automatic transfer switch is activated to detect the relevant electrical signals between the standby line and the corresponding bus II. These relevant electrical signals include: the voltage amplitude U1 of the standby line, the synchronization amplitude of the standby line and bus II, and the phase difference, including:

[0018] Check whether the voltage amplitude of the backup line meets the voltage criterion U1 > 0.7pu. If it does, determine the voltage amplitude difference and phase difference between the backup line and bus II. Otherwise, end the process.

[0019] Check whether the synchronization amplitude difference between the backup line and bus II meets the requirements of -0.3pu<ΔU<0.3pu and whether the frequency difference meets the requirements of -0.5Hz<Δf<0.5Hz. If they meet the requirements, check the synchronization phase difference; otherwise, disconnect the circuit breaker of the new energy system.

[0020] Check whether the phase difference between the backup line and bus II meets the requirement of -10° < ΔPh < 20°. If it does, close the circuit breaker at one end of the backup line directly; otherwise, adjust the output frequency of the new energy source.

[0021] Furthermore, frequency adjustment is performed, including:

[0022] Determine whether the voltage phase of bus II lags behind the voltage phase of the standby line. If so, adjust the output frequency of the new energy system to be greater than 50Hz; otherwise, adjust the output frequency to be less than 50Hz.

[0023] Furthermore, the phase difference between the backup line and bus II is continuously monitored, including:

[0024] Check if the phase difference between the standby line and bus II meets the requirement of -10° < ΔPh < 20°. If it does, close the circuit breaker at one end of the standby line; otherwise, continue to determine the phase difference.

[0025] Furthermore, a delay is made until the circuit breaker of the new energy system is detected to have successfully disconnected, at which point the no-voltage judgment of bus II is performed.

[0026] Furthermore, the no-voltage determination of bus II satisfies: bus voltage U BII <0.2pu.

[0027] The second objective of this invention is to provide a substation automatic transfer switch with synchronization detection, which activates the automatic transfer switch function by utilizing the signal of line voltage failure detected by the reclosing device.

[0028] The second objective of this invention is achieved by the following technical solution:

[0029] A substation automatic transfer switch for synchronization includes:

[0030] The detection module is used to block the reclosing of the circuit breaker at one end of the main power supply line when the reclosing fails on the power grid side of the main power supply line.

[0031] The processing module is used to activate the automatic transfer switch (ATS) and detect relevant electrical quantity signals between the standby line and the corresponding bus II. These signals include: standby line voltage amplitude, the difference in synchronous voltage amplitude between the standby line and bus II, voltage frequency difference, and voltage phase difference. Specifically, when the standby line voltage amplitude meets a preset criterion, the difference in synchronous voltage amplitude and voltage frequency between the standby line and bus II is judged; otherwise, the circuit breaker at one end of the standby line is blocked and the process ends. When the difference in synchronous amplitude and frequency between the standby line and bus II meets a preset criterion range, the synchronous phase difference is judged; otherwise, the circuit breaker of the new energy system is opened, and after a delay, a no-voltage judgment is performed on bus II. When the synchronous phase difference criterion is not met, the phase difference between bus II and the standby line voltage is judged; otherwise, the circuit breaker at one end of the standby line is directly closed. Based on the result of the phase difference judgment between bus II and the standby line voltage, the output frequency is adjusted. The phase difference between the standby line and bus II is continuously detected. If the detected phase difference meets the criterion, the circuit breaker at one end of the standby line is closed.

[0032] A third objective of this invention is to provide an electronic device for performing one of the objectives of the invention, comprising a processor, a storage medium, and a computer program, wherein the computer program is stored in the storage medium, and when the computer program is executed by the processor, it implements the above-mentioned substation automatic switching method for synchronizing and resetting.

[0033] A fourth objective of this invention is to provide a computer-readable storage medium storing one of the objectives of the invention, wherein a computer program is stored thereon, and when the computer program is executed by a processor, it implements the above-described substation automatic switching method for synchronizing and resetting.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] This invention provides a method for synchronizing and automatically switching on the backup line of a substation with distributed renewable energy access. By detecting the reclosing failure signal of the main power supply line and activating the automatic switching device, timely activation of the automatic switching reclosing and proper coordination with relay protection are achieved. During the synchronization process of the automatic switching, the same synchronization detection element can be shared with the reclosing function of the circuit breaker at one end of the main power supply line. That is, the synchronization detection of the two functions shares the same bus voltage signal. When executing the automatic switching process, it is only necessary to switch the line voltage signal channel from the main power supply line to the backup line. It is applicable to the access of distributed renewable energy. By utilizing the frequency adjustable characteristics of distributed renewable energy, the output frequency of renewable energy is adjusted according to the phase of the backup line, which speeds up the synchronization process of voltage signals on both sides of the circuit breaker, thereby shortening the time required from the activation of the automatic switching function to the activation of the backup line. Moreover, no large inrush voltage and inrush current are generated when the backup line is activated. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of a typical system structure under distributed new energy access in Implementation Example 1;

[0037] Figure 2 This is the phasor diagram of the phase a voltages on both sides of circuit breaker BRK4 in Example 1.

[0038] Figure 3 This is a flowchart of the substation synchronization backup automatic transfer method in Example 1;

[0039] Figure 4 This is a detailed flowchart of the substation synchronization and automatic switching method in Example 1;

[0040] Figure 5 This is a structural block diagram of the substation automatic switching device for synchronization and backup in Embodiment 2;

[0041] Figure 6 This is a structural block diagram of the electronic device in Embodiment 3. Detailed Implementation

[0042] The present invention will now be described in more detail with reference to the accompanying drawings. It should be noted that the following description of the present invention with reference to the accompanying drawings is merely illustrative and not restrictive. Various embodiments can be combined with each other to form other embodiments not shown in the following description.

[0043] Example 1

[0044] Example 1 provides a substation synchronization detection and automatic reclosing method, which aims to utilize the frequency adjustable characteristics of distributed renewable energy sources to adjust the output frequency of renewable energy sources according to the phase of the backup line, and realize automatic reclosing of the renewable energy system.

[0045] Please refer to Figure 1 As shown, the method in this embodiment is based on a typical system structure under distributed generation (DG) access. This system structure mainly includes a main power supply line, a backup line and the power grid connected to it, circuit breakers BRK1 and BRK2 at both ends of the main power supply line, circuit breakers BRK3 and BRK4 at both ends of the backup line, substation bus I, bus II and bus tie circuit breaker BRK5, new energy system circuit breaker BRK6, local load 1, local load 2, and distributed new energy power station DG. A fault f occurs on the main power supply line. When no fault occurs, BRK1, BRK2, BRK3, and BRK5 are closed, and BRK4 is in the open state. In this embodiment, the circuit breaker at one end of the main power supply line refers to BRK2, the energy circuit breaker refers to BRK6, and the circuit breaker at one end of the backup line refers to BEK4.

[0046] The voltage amplitude of the standby line is U1, its voltage phase is Ph1, and its voltage frequency is f1; the voltage amplitude of bus II is U2, its voltage phase is Ph2, and its voltage frequency is f2; the amplitude difference ΔU = U2 - U1, the frequency difference Δf = f2 - f1, and the phase difference ΔPh = Ph2 - Ph1 are denoted as follows:

[0047] After a fault f occurs on the main power supply line, circuit breakers BRK1 and BRK2 on both sides of the main power supply line trip, isolating fault f. After circuit breakers BRK1 and BRK2 trip, they enter the reclosing process. If reclosing fails, the automatic transfer switch process is initiated.

[0048] The principle of this method is explained below. When the voltage signals on both sides of the circuit breaker meet the synchronization conditions, the circuit breaker can be closed. Regarding the synchronization conditions, once the fault is isolated, as long as the systems on both sides of the faulty line do not become unstable, the voltage amplitude difference criterion and frequency difference criterion in the synchronization conditions will be automatically met. For the phase difference criterion, please refer to... Figure 2 As shown, taking phase A voltage as an example, U 2a The voltage of phase A of bus II has an angular velocity of ω2 and a phase of Ph2. 1a The A-phase voltage of the backup line has an angular velocity of w1 and a phase of Ph1. The phase difference between the two voltage signals is ΔPh = (Ph2 - Ph1). The magnitude of ΔPh needs to be adjusted based on the difference in angular velocities; the larger the difference in angular velocities, the faster ΔPh can be adjusted. The relationship between the initial phase difference ΔPh0, the difference in angular velocities, and the time Δt required for ΔPh to adjust to 0 is as follows:

[0049]

[0050] When the voltage frequencies w2 and w1 on both sides of the circuit breaker are very close, it will take a long time for ΔPh to adjust to the allowable closing range. According to the above formula, the initial value of ΔPh is uncontrollable when synchronizing conditions are first verified, and the angular frequency w1, determined by the large system, is also uncontrollable. To shorten the adjustment time ΔPh Δt, the rated output frequency of the new energy power supply can be adjusted to increase the angular frequency difference, thereby accelerating the change rate of ΔPh and speeding up the reclosing process.

[0051] Let f be the allowable frequency for the new energy islanding system in the local power grid. x The range is:

[0052] f min <f x <f max ;

[0053] When the voltage phase on the isolated renewable energy system side leads the voltage phase on the system side (ΔPh0 > 0), the output frequency of the renewable energy power supply needs to be reduced. Considering a certain safety margin, the rated frequency of the renewable energy power supply can be adjusted to:

[0054] f Nmin =f min +α+β;

[0055] In the formula f Nmin To adjust the target, α is the fluctuation amplitude of the new energy output frequency, and β is the safety margin, which can be 0.1Hz or other values ​​depending on the actual situation.

[0056] When Δδ0 < 0, the output frequency of the new energy power supply needs to be increased. Considering a certain safety margin, the rated frequency of the new energy power supply can be adjusted to:

[0057] f Nmax =f max -α-β;

[0058] In the formula f Nmax To adjust the target, α is the fluctuation amplitude of the new energy output frequency, and β is the safety margin, which can be 0.1Hz or other values ​​depending on the actual situation.

[0059] Based on the above principles, please refer to Figure 3 The flowchart shown and Figure 4 The overall flowchart shown illustrates a method for automatic switching of substation synchronization backup, which includes the following steps:

[0060] S1. When the reclosing failure of the main power supply line on the grid side is detected, the reclosing of the circuit breaker at one end of the main power supply line is blocked.

[0061] S1 also includes a main power supply line fault, in which the relay protection device disconnects the circuit breaker BRK2 at one end of the main power supply line.

[0062] The procedure for activating the circuit breaker at one end of the main power supply line to detect synchronization and reclosing includes: at the set reclosing time, detecting whether there is voltage on the main power supply line; if there is voltage, closing the circuit breaker when the voltage on both sides is synchronized; otherwise, blocking the reclosing, thus forming an islanded system between the new energy source and the load.

[0063] S2. Start the automatic transfer switch and detect the relevant electrical quantity signals between the standby line and bus II. The relevant electrical quantities include: standby line voltage amplitude, voltage amplitude difference between the standby line and bus II, voltage frequency difference, and voltage phase difference.

[0064] When the voltage amplitude of the backup line meets the preset criteria, the difference in synchronous amplitude between the backup line and bus II is judged; otherwise, the circuit breaker at one end of the backup line is blocked and the process ends.

[0065] When the synchronous amplitude of the backup line and bus II meets the preset amplitude range, the synchronous phase difference is judged; otherwise, the circuit breaker of the new energy system is disconnected and the bus II is de-voltage judged after a delay. When the de-voltage criterion is met, the circuit breaker at one end of the backup line is closed; otherwise, the circuit breaker at one end of the backup line is locked and the process ends.

[0066] The above-mentioned no-voltage judgment for bus II satisfies: bus voltage U BII <0.2pu.

[0067] If the synchronous phase difference criterion is not met, the phase difference between bus II and voltage and the phase difference between standby line voltage are judged; otherwise, the circuit breaker at one end of the standby line is closed.

[0068] S2 specifically includes: checking whether the voltage criterion of the backup line meets U1>0.7pu. If it meets the criterion, it performs a judgment on the synchronous amplitude difference between the backup line and bus II; otherwise, it ends the process.

[0069] Check whether the synchronization amplitude difference between the backup line and bus II meets the requirements of -0.3pu<ΔU<0.3pu and whether the frequency difference meets the requirements of -0.5Hz<Δf<0.5Hz. If they meet the requirements, check the synchronization phase difference; otherwise, disconnect the circuit breaker of the new energy system.

[0070] Check whether the phase difference between the backup line and bus II meets the requirement of -10° < ΔPh < 20°. If it meets the requirement, close the circuit breaker at one end of the backup line; otherwise, adjust the output frequency of the new energy source.

[0071] S3. Based on the judgment results of the voltage phase of bus II and the voltage phase of the standby line, adjust the output frequency of the new energy source;

[0072] Adjusting the output frequency includes:

[0073] Determine whether the voltage phase of bus II lags behind the voltage phase of the standby line. If so, adjust the output frequency of the new energy system to be greater than 50Hz; otherwise, adjust the output frequency to be less than 50Hz.

[0074] S4. Continue to check the phase difference between the standby line and bus II;

[0075] S4 includes:

[0076] Check if the phase difference between the standby line and bus II meets the requirement of -10° < ΔPh < 20°. If it does, close the circuit breaker at one end of the standby line; otherwise, continue to determine the phase difference.

[0077] Disconnect the circuit breaker of the new energy system.

[0078] S5. If the phase difference detected continues to meet the criteria, close the circuit breaker at one end of the standby line.

[0079] It should be noted that the various judgment values ​​involved in this embodiment are based on existing circuit settings, and can be modified according to different circuit systems in actual use.

[0080] Example 2

[0081] Example 2 discloses a device corresponding to the substation synchronization and automatic switching method of the above embodiments. It is a virtual device structure of the above embodiments. Please refer to [link / reference]. Figure 5 As shown, it includes:

[0082] The detection module 210 is used to block the reclosing of the circuit breaker at one end of the main power supply line when the reclosing of the main power supply line fails to be detected on the grid side.

[0083] Processing module 220 is used to activate the automatic transfer switch and detect the no-voltage failure signal of the backup line. The no-voltage failure signal includes: the voltage amplitude of the backup line, the synchronization amplitude of the backup line and bus II, and the synchronization phase difference. Specifically, when the voltage amplitude of the backup line meets a preset criterion, the synchronization amplitude difference between the backup line and bus II is judged; otherwise, the circuit breaker at one end of the backup line is blocked and the process ends. When the synchronization voltage amplitude difference and frequency difference between the backup line and bus II meet a preset criterion range, the synchronization phase difference is judged; otherwise, the circuit breaker of the new energy system is opened, and after a delay, the no-voltage judgment of bus II is performed. When the synchronization phase difference criterion is not met, the phase difference between bus II and the voltage of the backup line is judged; otherwise, the circuit breaker at one end of the backup line is directly closed. Based on the result of the phase difference judgment between bus II and the voltage of the backup line, the output frequency of the new energy is adjusted. The phase difference between the backup line and bus II is continuously detected. If the continuously detected phase difference meets the criterion, the circuit breaker at one end of the backup line is closed.

[0084] Preferably, in the event of a fault in the main power supply line, the relay protection device will disconnect the circuit breaker at one end of the main power supply line.

[0085] The procedure for activating the circuit breaker at one end of the main power supply line to detect synchronization and reclosing includes: detecting whether there is voltage on the line; if there is voltage, closing the circuit breaker when the voltage on both sides is synchronized; otherwise, blocking reclosing to form an islanded system between the new energy source and the load.

[0086] Preferably, the automatic transfer switch is activated to detect the relevant electrical quantity signals between the standby line and the corresponding bus II. These relevant electrical quantity signals include: the voltage amplitude U1 of the standby line, the synchronous amplitude, frequency difference, and phase difference between the standby line and bus II, including:

[0087] Check whether the voltage criterion of the backup line meets U1>0.7pu. If it does, judge the synchronous amplitude difference and frequency difference between the backup line and bus II; otherwise, end the process.

[0088] Check whether the synchronization amplitude difference between the backup line and bus II meets the requirements of -0.3pu<ΔU<0.3pu and whether the frequency difference meets the requirements of -0.5Hz<Δf<0.5Hz. If they meet the requirements, check the synchronization phase difference; otherwise, disconnect the circuit breaker of the new energy system.

[0089] Check whether the phase difference between the backup line and bus II meets the requirement of -10° < ΔPh < 20°. If it meets the requirement, close the circuit breaker at one end of the backup line; otherwise, adjust the output frequency of the new energy source.

[0090] Preferably, the phase difference between the backup line and bus II is further detected, including:

[0091] Check if the phase difference between the standby line and bus II meets the requirement of -10° < ΔPh < 20°. If it does, close the circuit breaker at one end of the standby line; otherwise, continue to determine the phase difference.

[0092] Example 3

[0093] Figure 6 This is a schematic diagram of the structure of an electronic device provided in Embodiment 3 of the present invention, as shown below. Figure 6 As shown, the electronic device includes a processor 310, a memory 320, an input device 330, and an output device 340; the number of processors 310 in the computer device can be one or more. Figure 6 Taking a processor 310 as an example; the processor 310, memory 320, input device 330, and output device 340 in the electronic device can be connected via a bus or other means. Figure 6 Taking the example of a connection between China and Israel via a bus.

[0094] The memory 320, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the substation automatic switching method for synchronizing and backing up in this embodiment of the invention. The processor 310 executes various functional applications and data processing of the electronic device by running the software programs, instructions, and modules stored in the memory 320, thereby implementing the substation automatic switching method for synchronizing and backing up in Embodiment 1 described above.

[0095] The memory 320 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function; the data storage area may store data created based on terminal usage. Furthermore, the memory 320 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 320 may further include memory remotely located relative to the processor 310, which can be connected to the electronic device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0096] Input device 330 can be used to receive input user identity information, circuit system data, etc. Output device 340 may include display devices such as a display screen.

[0097] Example 4

[0098] Embodiment 4 of the present invention also provides a storage medium containing computer-executable instructions, which can be used by a computer to execute a substation synchronization and automatic switching method, the method comprising:

[0099] When a failure to reclose on the main power supply line is detected, the reclosing of the circuit breaker at one end of the main power supply line is blocked.

[0100] Start the automatic transfer switch and detect the voltage failure signal of the backup line. The voltage failure signal includes: the voltage amplitude of the backup line, the synchronous amplitude of the backup line and bus II, and the synchronous phase difference.

[0101] When the voltage amplitude of the backup line meets the preset judgment amplitude, the synchronous amplitude difference and frequency difference between the backup line and bus II are judged; otherwise, the circuit breaker at one end of the backup line is blocked and the process ends.

[0102] When the synchronous amplitude of the backup line and bus II meets the preset amplitude range, the synchronous phase difference is judged; otherwise, the circuit breaker of the new energy system is disconnected and the bus II is de-voltage judged after a delay. When the de-voltage criterion is met, the circuit breaker at one end of the backup line is closed; otherwise, the circuit breaker at one end of the backup line is locked and the process ends.

[0103] When the synchronous phase difference criterion is not met, the phase difference between bus II and voltage and the phase difference between standby line voltage are judged; otherwise, the circuit breaker at one end of the standby line is closed directly.

[0104] Based on the judgment results of the voltage phase of bus II and the voltage phase of the backup line, adjust the output frequency of the new energy source;

[0105] Continue to monitor the phase difference between the backup line and bus II;

[0106] If the phase difference detected continues to meet the criteria, close the circuit breaker at one end of the backup line.

[0107] Of course, the computer-executable instructions provided in the embodiments of the present invention are not limited to the method operations described above, but can also execute related operations in the substation synchronization and automatic switching method provided in any embodiment of the present invention.

[0108] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause an electronic device (which may be a mobile phone, personal computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0109] It is worth noting that in the above embodiments of the substation automatic switching method device, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy differentiation and are not used to limit the scope of protection of the present invention.

[0110] For those skilled in the art, various other corresponding changes and modifications can be made based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of this invention.

Claims

1. A method for automatic switching of synchronizing backup power in a substation, characterized in that, Includes the following steps: When a failure to reclose on the main power supply line is detected, the reclosing of the circuit breaker at one end of the main power supply line is blocked. The automatic transfer switch is activated, and the relevant electrical quantity signals of the backup line and the corresponding bus II are detected. The relevant electrical quantity signals include: the voltage amplitude of the backup line, the voltage amplitude of the corresponding bus II, and the voltage amplitude difference, voltage frequency difference, and voltage phase difference between the backup line and bus II. Specifically, when the voltage amplitude of the backup line meets the preset amplitude criterion, the voltage synchronization amplitude difference and frequency difference between the backup line and bus II are judged; otherwise, the circuit breaker at one end of the backup line is blocked and the process ends. When the synchronization amplitude difference and frequency difference between the backup line and bus II meet the preset criteria, the synchronization phase difference is judged; otherwise, the new energy system circuit breaker is disconnected and the bus II is de-voltage judged after a delay. When the de-voltage criterion is met, the circuit breaker at one end of the backup line is closed; otherwise, the circuit breaker at one end of the backup line is locked and the process ends. If the synchronization phase difference criterion is not met, the phase difference between bus II and voltage and the phase difference between the backup line voltage are judged; otherwise, the circuit breaker at one end of the backup line is closed directly. Based on the judgment results of the voltage phase of bus II and the voltage phase of the backup line, adjust the output frequency of the new energy source; Continue to monitor the phase difference between the backup line and bus II; When the phase difference criterion is met, the circuit breaker at one end of the standby line is closed.

2. The substation synchronization and automatic switching method as described in claim 1, characterized in that, Failure of reclosing on the power grid side includes: If the main power supply line fails, the relay protection device will disconnect the circuit breaker at one end of the main power supply line. The procedure for activating the circuit breaker at one end of the main power supply line to detect synchronization and reclosing includes: detecting whether there is voltage on the main power supply line; if there is voltage, closing the circuit breaker when the voltage on both sides is synchronized; otherwise, blocking reclosing, thus forming an islanded system between the new energy source and the load.

3. The substation synchronization and automatic switching method as described in claim 1, characterized in that, Activate the automatic transfer switch and detect the relevant electrical signals of the standby line and the corresponding bus II. These signals include: the voltage amplitude U1 of the standby line, the synchronization amplitude of the standby line and bus II, and the phase difference. Check whether the voltage amplitude of the backup line meets the voltage criterion U1 > 0.7pu. If it does, determine the voltage amplitude difference and phase difference between the backup line and bus II. Otherwise, end the process. Check whether the synchronization amplitude difference between the backup line and bus II meets the requirements of -0.3pu<ΔU<0.3pu and whether the frequency difference meets the requirements of -0.5Hz<Δf<0.5Hz. If they meet the requirements, check the synchronization phase difference; otherwise, disconnect the circuit breaker of the new energy system. Check whether the phase difference between the backup line and bus II meets the requirement of -10° < ΔPh < 20°. If it does, close the circuit breaker at one end of the backup line directly; otherwise, adjust the output frequency of the new energy source.

4. The substation synchronization and automatic switching method as described in claim 3, characterized in that, Frequency adjustment includes: Determine whether the voltage phase of bus II lags behind the voltage phase of the standby line. If so, adjust the output frequency of the new energy system to be greater than 50Hz; otherwise, adjust the output frequency to be less than 50Hz.

5. The substation synchronization and automatic switching method as described in claim 1, characterized in that, Continue monitoring the phase difference between the backup line and bus II, including: Check if the phase difference between the standby line and bus II meets the requirement of -10° < ΔPh < 20°. If it does, close the circuit breaker at one end of the standby line; otherwise, continue to determine the phase difference.

6. The substation synchronization and automatic switching method as described in claim 1 or 5, characterized in that, The delay continues until the circuit breaker of the new energy system is successfully disconnected, at which point the no-voltage judgment of bus II is performed.

7. The substation synchronization and automatic switching method as described in claim 6, characterized in that, The no-voltage determination for bus II satisfies: bus voltage U BII <0.2pu.

8. A substation synchronization and automatic transfer switch, characterized in that, It includes: The detection module is used to block the reclosing of the circuit breaker at one end of the main power supply line when the reclosing fails on the power grid side of the main power supply line. The processing module is used to activate the automatic transfer switch (ATS) and detect the no-voltage failure signal of the backup line. The no-voltage failure signal includes: the voltage amplitude of the backup line, the synchronization amplitude of the backup line and bus II, and the synchronization phase difference. It also activates the ATS to detect relevant electrical quantity signals between the backup line and the corresponding bus II. These relevant electrical quantity signals include: the voltage amplitude of the backup line, the voltage amplitude of the corresponding bus II, and the voltage amplitude difference, voltage frequency difference, and voltage phase difference between the backup line and bus II. Specifically, when the voltage amplitude of the backup line meets a preset amplitude criterion, the synchronization amplitude difference and frequency difference between the backup line and bus II are judged; otherwise, the circuit breaker at one end of the backup line is blocked and the process ends. When the synchronization amplitude difference and frequency difference of line II meet the preset criteria, the synchronization phase difference is judged; otherwise, the circuit breaker of the new energy system is disconnected and the no-voltage judgment of bus II is performed after a delay. If the no-voltage judgment is met, the circuit breaker at one end of the backup line is closed; otherwise, the circuit breaker at one end of the backup line is locked and the process ends. When the synchronization phase difference judgment is not met, the phase difference between bus II and voltage and the phase difference between the backup line and voltage are judged; otherwise, the circuit breaker at one end of the backup line is closed directly. According to the result of the phase difference judgment between bus II and voltage and the phase difference between the backup line and voltage, the output frequency of the new energy is adjusted. The phase difference between the backup line and bus II is detected again. When the phase difference judgment is met, the circuit breaker at one end of the backup line is closed.

9. An electronic device comprising a processor, a storage medium, and a computer program, wherein the computer program is stored in the storage medium, characterized in that, When the computer program is executed by the processor, it implements the substation automatic switching method for synchronous backup as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the substation automatic switching method for synchronous backup as described in any one of claims 1 to 7.

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