Multifunctional load regulating standby power switching device and control method

Abstract

The application relates to a multifunctional load regulating standby power switching device and a control method. The control method monitors the operation of a high-voltage system and a load rate on line, controls the opening and closing of each switch when a fault occurs, adjusts and controls multiple-loop low-voltage loads, controls the load rate in the range that can be borne by the high-voltage system, switches the standby power, and then adjusts again according to the load rate to restore the operation of the low-voltage load, thereby avoiding the problem that the system is instantaneously impacted and voltage fluctuation is caused due to the input of the standby power, improving the system operation safety, and avoiding the problems of capacity waste and electric energy loss.

Description

Technical Field

[0001] This invention belongs to the field of power system technology, and particularly relates to a multifunctional load regulation backup power switching device and control method. Background Technology

[0002] Currently, existing power systems typically employ multiple power sources. For example, in a 10kV power system, a single busbar segmented, single busbar dual-incoming-line power supply method is used. These two power sources are either primary and backup, or mutually backup. When one power source is disconnected due to a fault, the system can automatically switch to the other power source via a backup power switching device. However, the applicant has found that when the backup power source is activated, the system load increases significantly, sometimes reaching twice the normal operating load, causing instantaneous impacts on the system, resulting in voltage fluctuations and jeopardizing the safe operation of the system. This is usually addressed by increasing the transformer capacity, leading to significant capacity waste and energy loss. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, this invention provides a multifunctional load regulation backup power switching device and control method.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] In a first aspect, the control method of the multi-functional load regulation backup power switching device of the present invention monitors the operation status and load rate of the high-voltage system online, and controls the opening and closing of each switch when a fault occurs, regulates and controls the low-voltage load of multiple circuits, controls the load rate within the range that the high-voltage system can bear, switches the backup power supply, and then performs secondary adjustment according to the load rate to restore the low-voltage load operation.

[0006] The control method described in this invention collects and records the load current of the two power sources. Before the backup power source is put into operation, it can realize the programmable logic sequence switching of multiple low-voltage loads, prioritize the disconnection of tertiary loads, reduce the load rate of the distribution transformer, and then put the backup power source into operation. After the backup power source is put into operation, it automatically adjusts and restores the power supply of some tertiary loads according to the load rate. This avoids the problem of instantaneous impact on the system caused by the backup power source being put into operation, which causes voltage fluctuations. This improves the safety of system operation and avoids the problems of capacity waste and power loss.

[0007] Furthermore, the control method includes:

[0008] S1. Online detection and judgment of whether the backup automatic transfer meets the charging conditions, and when the charging conditions are met, the system performs a working power supply failure and voltage loss judgment.

[0009] S2. When it is determined that the system has experienced a power supply failure and voltage loss, search for the fault type and fault area corresponding to the power supply failure and adaptively match the corresponding working mode.

[0010] S3. Determine whether the working mode corresponding to the adaptive matching in S2 meets the discharge conditions, and if the discharge conditions are not met, start the backup automatic transfer and disconnect the switch associated with the working mode;

[0011] S4. Determine whether the switch that tripped in S3 is in the open position, and after the switch trips to the open position, determine whether the fault area where the working power supply is de-voltaged is without voltage and without current, and execute the load shedding strategy when the fault area where the working power supply is de-voltaged is without voltage and without current.

[0012] S5. After the load shedding strategy is successfully executed, the standby automatic transfer switch is activated;

[0013] S6. Determine whether the corresponding standby automatic transfer switch of the working mode is in the closed position, and after confirming that the standby automatic transfer switch is in the closed position, execute the load connection strategy.

[0014] S7. After the load input strategy is successfully executed, restore low-voltage load operation to the fault area where the working power supply has lost voltage.

[0015] Furthermore, the execution of the load shedding strategy described in S4 includes:

[0016] S41. Determine the fault type and fault area of ​​the power supply failure, and adaptively match the corresponding working mode;

[0017] S42. At the instant of high-voltage side loss of voltage, record the number of low-voltage side loads of the downstream loads connected to the faulty power source.

[0018] S43. Optimize the load shedding control strategy;

[0019] S44. Detect the switching status of the faulty power source and the downstream loads connected to the faulty power source, and determine whether the load shedding strategy was successfully executed.

[0020] Furthermore, the optimized load shedding control strategy described in S43 includes: direct shedding of high-voltage side loads and direct shedding of low-voltage side loads.

[0021] Furthermore, the direct disconnection of the high-voltage side load includes: at the moment of high-voltage system failure, recording the load current when the low-voltage system fails, and selecting the low-voltage system switch disconnection method by setting the low-voltage load rate;

[0022] The direct disconnection of the low-voltage side load includes: cyclically scanning the downstream load and load importance, and disconnecting the three-level load switches with a load rate greater than a preset value during operation.

[0023] Furthermore, the implementation of the load assignment strategy described in S6 includes:

[0024] S61. Provide a backup automatic transfer switch;

[0025] S62. Optimize the load control strategy based on the aforementioned automatic transfer switch;

[0026] S63. Provide high-voltage side feeder switches in sequence, and after confirming that the high-voltage side feeder switches are in the closed position, provide low-voltage side incoming line switches and low-voltage side feeder switches in sequence; otherwise, provide low-voltage side tie switches and low-voltage side backup power switches.

[0027] S64. Detect the switching status of the faulty power source and the downstream loads connected to the faulty power source, and determine whether the load activation strategy was successfully executed.

[0028] Furthermore, the optimized load control strategy described in S62 includes:

[0029] At the moment of high voltage system failure, the high voltage system and low voltage system record the load current at the time of failure, and select the fast switching mode or the step-by-step switching mode of the high voltage system and low voltage system switches based on the set low voltage load rate.

[0030] The low-voltage system is put into operation according to load type, and the three levels of low-voltage loads to be put into or taken out are determined based on the load size and importance.

[0031] The high-voltage system delay and the low-voltage ATS delay settings are coordinated and completed.

[0032] Secondly, the present invention also provides a multifunctional load-regulating backup power switching device, comprising:

[0033] The acquisition module is used to monitor the operation and load rate of the high-voltage system online. Specifically, it acquires the switch and current signals on the high-voltage side and the low-voltage side. Based on the switch and current signals, it monitors the load rate of the bus and the load current and switch status of each low-voltage circuit.

[0034] In addition, the logic control module is used to control the opening and closing of each switch based on the online monitoring of the high-voltage system's operating status and load rate, and in the event of a fault.

[0035] Furthermore, the logic control module includes:

[0036] The model building unit is used for adaptive modeling of backup automatic switching based on the associated attributes of components in a dual-power system.

[0037] The first optimization unit is used to optimize the load control strategy and the load shedding strategy based on the established standby self-starting adaptive model.

[0038] The second optimization unit is used to adaptively optimize the standby self-starting working mode based on the load input control strategy and the load cut-off control strategy.

[0039] The discrimination unit is used to determine the fault type and fault area of ​​the power supply loss based on the automatic backup switching working mode.

[0040] And the matching and tracking unit is used to match and control the automatic switchover control strategy in real time based on the fault area and fault type.

[0041] For the various aspects of the second aspect mentioned above and the technical effects that each aspect may achieve, please refer to the above description of the technical effects that can be achieved for the first aspect or the various possible solutions in the first aspect, which will not be repeated here. Attached Figure Description

[0042] Figure 1 This is a flowchart illustrating the control method of the multifunctional load regulating backup power switching device of the present invention.

[0043] Figure 2 This is a schematic diagram of the process of executing the load shedding strategy in the control method of the multifunctional load regulating backup power switching device of the present invention;

[0044] Figure 3 This is a flowchart illustrating the execution of the load-in strategy in the control method of the multifunctional load-regulating backup power switching device of the present invention.

[0045] Figure 4 This is a flowchart illustrating the control method described in an embodiment of the present invention;

[0046] Figure 5 This is a flowchart illustrating the load shedding strategy in the control method described in this embodiment of the invention;

[0047] Figure 6 This is a flowchart illustrating the load application strategy in the control method described in this embodiment of the invention.

[0048] Figure 7 This is a schematic block diagram of the structure of the multifunctional load regulating backup power switching device of the present invention;

[0049] Figure 8 This is a schematic diagram of a 10KV power system according to an embodiment of the present invention;

[0050] Figure 9 This is a schematic diagram of a multi-functional load regulation backup power switching device in a 10KV power system according to an embodiment of the present invention. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0052] The control method of a multi-functional load regulation backup power switching device described in this invention monitors the operation and load rate of the high-voltage system online, and controls the opening and closing of each switch in the event of a fault. This regulates and controls the low-voltage load across multiple circuits, keeping the load rate within the tolerance range of the high-voltage system. Then, the backup power supply is switched, and a secondary adjustment is performed based on the load rate to restore low-voltage load operation. Figure 1 As shown, the control method includes the following steps:

[0053] Step S1. Online detection and determination of whether the automatic transfer switch meets the charging conditions, and if the charging conditions are met, the system performs a power supply failure and voltage loss judgment; wherein,

[0054] The charging conditions are specifically as follows: both high-voltage busbars are energized, both high-voltage incoming line switches are closed, the high-voltage bus tie is open, and the automatic transfer switch without interlocking signal and the automatic transfer switch function is activated; or, both high-voltage busbars are energized, one high-voltage incoming line switch is closed, the other high-voltage incoming line switch is open, the high-voltage bus tie is open, and the automatic transfer switch without interlocking signal and the automatic transfer switch function is activated.

[0055] The aforementioned judgment of power supply failure and voltage loss of the system specifically includes: determining whether one of the two high-voltage busbars is undervoltage and the other is energized, whether there is no current in the incoming line of the undervoltage busbar, and whether the incoming switch of the undervoltage busbar has performed a no-current protection action; or, determining whether both high-voltage busbars are undervoltage, whether there is no current in the high-voltage main incoming line, and whether the main incoming switch has performed a no-current protection action.

[0056] Step S2. When it is determined that the system has experienced a power supply failure, search for the fault type and fault area corresponding to the power supply failure and adaptively match the corresponding working mode.

[0057] Specifically, based on S1, the system collects the voltage of the high-voltage busbars on both sides to determine which of the following is the cause of the power supply failure: high-voltage failure, high-voltage feeder switch on the failure side, low-voltage incoming line voltage on the failure side, no current in the low-voltage incoming line on the failure side, current in each low-voltage circuit on the failure side, or feeder switch in each low-voltage circuit on the failure side. Then, the system prompts the model to establish a unit adaptive matching corresponding working mode, which includes high-voltage standby automatic transfer mode and low-voltage load switching mode.

[0058] Step S3. Determine whether the working mode corresponding to the adaptive matching in S2 meets the discharge conditions, and if the discharge conditions are not met, start the automatic transfer switch and disconnect the switch associated with the working mode.

[0059] Step S4. Determine whether the switch that tripped in S3 is in the open position. After the switch trips to the open position, determine whether the pressure loss area is without pressure and without current. If the pressure loss area is without pressure and without current, execute the load shedding strategy. Wherein, if... Figure 2 As shown, the execution of the load shedding strategy includes:

[0060] S41. Determine the fault type and fault area of ​​the power supply loss, and adaptively match the corresponding working mode. The method of determining the fault type and fault area, as well as the adaptive matching method of the corresponding working mode, are the same as in step S2, and will not be repeated here.

[0061] S42. At the instant of high-voltage side loss of voltage, record the number of low-voltage side loads of the downstream loads connected to the faulty power source.

[0062] S43. Optimize the load shedding control strategy, which includes: direct shedding of high-voltage side loads and direct shedding of low-voltage side loads; the direct shedding of high-voltage side loads includes: recording the load current of the low-voltage system at the moment of high-voltage system failure, and selecting the low-voltage system switch to select the shedding mode based on the set low-voltage load rate; because the recording of the low-voltage load current during high-voltage system failure is used for the direct shedding strategy of low-voltage side loads, when the low-voltage side load is lower than the set load rate, the low-voltage load is skipped, because a low low-voltage load rate will not cause the low-voltage load to impact the high-voltage system after the high-voltage system's automatic transfer switch; when the low-voltage side load is higher than the set load rate, the direct shedding strategy of low-voltage side loads is executed.

[0063] The direct disconnection of the low-voltage side load includes: cyclically scanning the downstream load and load importance, and disconnecting the three-level load switches with a load rate greater than a preset value during operation;

[0064] S44. Detect the switching status of the faulty power source and its downstream loads to determine whether the load shedding strategy was successfully executed. Specifically, the acquisition module samples the switching status of the faulty power source and its downstream loads and transmits it to the matching tracking unit module. The tracking unit module compares the switching status of the downstream load with the switching status after the working mode is completed to determine whether the load shedding strategy was successfully executed. That is, it determines whether all the switching positions of the downstream loads are in the neutral position. If so, the load shedding strategy is determined to be successfully executed; otherwise, it is determined to be unsuccessful.

[0065] Step S5. After the load shedding strategy is successfully executed, turn on the automatic transfer switch.

[0066] Step S6. Determine whether the corresponding automatic transfer switch for the operating mode is in the closed position, and after confirming that the automatic transfer switch is in the closed position, execute the load connection strategy. Wherein, for example... Figure 3 As shown, the execution of the load allocation strategy includes:

[0067] S61. Provide a backup automatic transfer switch;

[0068] S62. Optimize the load control strategy based on the backup automatic transfer switch; wherein the optimized load control strategy includes:

[0069] 1. At the moment of voltage loss in the high-voltage system, the high-voltage system and the low-voltage system record the load current at the time of voltage loss, and select the fast switching mode or the step-by-step switching mode of the high-voltage system and the low-voltage system switch based on the set low-voltage load rate.

[0070] 2. Low-voltage system activation is based on load type, with the activation and deactivation of three levels of low-voltage loads determined according to load size and importance;

[0071] 3. The high-voltage system delay and the low-voltage ATS delay settings are coordinated. Because the high-voltage system overcurrent protection cannot activate the automatic transfer switch (high-voltage incoming line overcurrent protection, high-voltage feeder overcurrent protection, or high-voltage bus tie overcurrent protection), and under the optimized load control strategy, the low-voltage ATS activates the low-voltage backup power supply to restore the low-voltage load on the undervoltage side.

[0072] S63. Provide high-voltage side feeder switches in sequence, and after confirming that the high-voltage side feeder switches are in the closed position, provide low-voltage side incoming line switches and low-voltage side feeder switches in sequence; otherwise, provide low-voltage side tie switches and low-voltage side backup power switches.

[0073] S64. Detect the switching status of the faulty power supply point and the downstream loads connected to the faulty power supply, and determine whether the load activation strategy has been successfully executed; the specific process is the same as S44 above, and will not be repeated here.

[0074] Step S7. After the load transfer strategy is successfully executed, restore low-voltage load operation to the fault area where the working power supply has lost voltage. In this way, the problem of load impact on the high-voltage side lines and busbars caused by the combined effects of low-voltage load closing and inrush current of the high-voltage side feeder transformer during the existing high-voltage standby automatic transfer process can be successfully solved.

[0075] Furthermore, the low-voltage circuit control is performed via an ATS (Automatic Transfer Switch).

[0076] The control method of the multifunctional load regulating backup power switching device of the present invention will be further described below through embodiments.

[0077] like Figure 4 As shown, the control method of the multi-functional load regulating backup power switching device described in this embodiment specifically includes:

[0078] S101: Online detection to see if the automatic transfer switch meets the charging conditions; if the charging conditions are met, proceed to S102; if the charging conditions are not met, end.

[0079] S102: Determine if the system has experienced a power supply failure; if the system has experienced a power supply failure, proceed to S103; if the system has not experienced a power supply failure, end the process.

[0080] S103: Search for the fault type and fault area corresponding to the power supply failure, and adaptively match the corresponding working mode;

[0081] S104: Determine whether the working mode meets the discharge conditions; if the discharge conditions are not met, proceed to S105; if the discharge conditions are met, end.

[0082] S105: Start automatic transfer switch and disconnect the switch associated with the working mode;

[0083] S106: Within the preset delay time, confirm whether the switch associated with the trip working mode is in the open position; if yes, proceed to S107; if no, end.

[0084] S107: Determine whether the pressure loss area is without pressure and without flow; if yes, proceed to S108; if no, end.

[0085] S108: Execute the load shedding strategy;

[0086] S109: Determine if the load shedding strategy was successfully executed; if yes, proceed to S110; otherwise, end.

[0087] S110: Activate the automatic transfer switch;

[0088] S111: Within the preset delay time, confirm whether the corresponding standby automatic transfer switch of the working mode is in the closed position; if yes, then execute S112; if no, then end.

[0089] S112: Execute the load input strategy;

[0090] S113: Determine whether the load allocation strategy was successfully executed; if yes, proceed to S114; if no, end.

[0091] S114: Determine whether the voltage in the undervoltage area has been restored; if yes, proceed to S115; if no, end.

[0092] S115: Determine whether the automatic transfer switch was successful.

[0093] In this embodiment, as Figure 5 As shown, the process of the load shedding strategy is as follows:

[0094] S201: Determine the type and area of ​​the power supply undervoltage fault and adaptively match the corresponding working mode;

[0095] S202: Record the load at the moment of power failure at the fault power source and the downstream load connected to the fault power source;

[0096] S203: Optimize load shedding control strategy;

[0097] S204: Detect the faulty power supply point and the switching status of the downstream loads connected to the faulty power supply.

[0098] In this embodiment, as Figure 6 As shown, the process of implementing the load strategy includes:

[0099] S301: Successfully activated standby automatic transfer switch;

[0100] S302: Optimize the load control strategy;

[0101] S303: Sequentially connect the high-voltage side feeder switches to no-load operation;

[0102] S304: Confirm whether the high-voltage side feeder switch is closed; if yes, proceed to S305; if no, proceed to S308.

[0103] S305: Determine whether the low-voltage side incoming line switch should be switched on sequentially; if yes, proceed to S306; if no, proceed to S308.

[0104] S306: Sequentially switch on the low-voltage side feeder;

[0105] S307: Detect the faulty power source and the status of the downstream load switches connected to the faulty power source;

[0106] S308: Determine if it is a low-voltage side tie switch; if yes, proceed to S309;

[0107] S309: Turn on the low-voltage side standby power switch; then execute S307.

[0108] like Figure 7 As shown, the present invention also provides a multifunctional load-regulating backup power switching device, comprising:

[0109] The acquisition module 100 is used to monitor the operation and load rate of the high-voltage system online. Specifically, it acquires the switch and current signals on the high-voltage side and the low-voltage side. Based on the switch and current signals, it monitors the load rate of the bus and the load current and switch status of each low-voltage circuit.

[0110] And the logic control module 200 is used to control the opening and closing of each switch according to the online monitoring of the high voltage system's operating status and load rate, and in the event of a fault.

[0111] Furthermore, the logic control module 200 includes:

[0112] The model building unit 201 is used for adaptive modeling of backup automatic transfer based on the associated attributes of components in a dual power supply system. For example, given the existing conventional bus backup automatic transfer and high-voltage system wiring diagrams, the model building unit 201 determines the backup automatic transfer mode of the high-voltage system according to the high-voltage system operation mode, and establishes an associated control model for the low-voltage load switches connected to the two high-voltage bus sections.

[0113] The first optimization unit 202 is used to optimize the load control strategy and the load shedding strategy based on the established standby self-start adaptive modeling.

[0114] The second optimization unit 203 is used to adaptively optimize the standby automatic transfer working mode based on the load control strategy and the load shedding control strategy. Specifically, when the load shedding control strategy is activated, the low-voltage load loses voltage due to the loss of voltage of the high-voltage system incoming line. According to the standby automatic transfer mode of the high-voltage system and the load ratio of the high-voltage system feeder load current and the corresponding low-voltage circuit load current at the moment of the high-voltage system incoming line loss, the corresponding high-voltage system switch and the three-level load switch of the low-voltage system on the loss side are disconnected. When the load control strategy is activated, the low-voltage circuit switches are activated in sequence according to the principle of high voltage first and then low voltage, and the load current and importance of each low-voltage circuit are determined.

[0115] The discrimination unit 204 is used to determine the fault type and fault area of ​​the power supply loss based on the automatic backup switching working mode.

[0116] And the matching and tracking unit 205 is used to match and control the automatic switching control strategy in real time based on the fault area and fault type.

[0117] like Figure 8 and 9 As shown, this embodiment uses a 10KV power system as a reference. The multi-functional load regulating backup power switching device of this embodiment includes:

[0118] Acquisition module: Acquires switch and current signals from multiple circuits (more than 10 circuits) of the 10kV system (601, 602, 600, 603, 604) and the 0.4kV low-voltage system (715, 714, 725, 724), thereby monitoring the load rate of 601 (section I busbar) and 604 (section II busbar), as well as the load current and switch status of each low-voltage circuit.

[0119] And the logic control module: controls the opening and closing of each switch according to the operating conditions and load rate.

[0120] During normal operation: two 10kV incoming lines, 601 is the main power supply for the 10kV I bus (switch closed), 604 is the main power supply for the 10kV VII bus (switch closed), and 600 is the bus tie section switch (switch open). Each bus section operates independently with its own load (bus I is energized, bus II is energized, 601 is closed, 604 is closed, 600 tie section is open, and the device completes charging after a delay).

[0121] When abnormal situation 1 (normal standby automatic transfer device) occurs: Bus I loses voltage and has no current, the device trips 601 switch after a delay, closes 600 switch, and 604 power supply simultaneously drives Bus I and Bus II to operate. The 1T transformer of switch 602 resumes operation, and the 0.4kV section 1 bus load is put into operation at the same time, and the system load increases instantaneously.

[0122] When abnormal situation 2 (normal standby automatic transfer device) occurs: Bus II loses voltage and has no current, the device trips 604 switch after a delay, closes 600 switch, and Bus I and Bus II are simultaneously powered by power supply 601. The 2T transformer of switch 603 resumes operation, and the 0.4kV section II bus load is put into operation at the same time, and the system load increases instantaneously.

[0123] When abnormal situation 3 (load regulation) occurs: Bus I loses voltage and there is no current. The device records the operating current and load rate of Bus I and Bus II before the voltage loss. The device trips switches 601 and 602 after a delay. The device calculates the load size of the low-voltage switches before the voltage loss and disconnects the tertiary loads. The number of circuits disconnected is calculated and determined by the preset load rate. After disconnecting switches 601 and 602, switches 600 and 602 are closed sequentially to restore power supply to the primary and secondary loads of the low-voltage system. After restoration, a second load regulation can be performed, and some tertiary loads can be restored as needed (the priority and load rate of the restored circuits can be set). The purpose of disconnecting switch 602 is to prevent multiple transformers from starting directly after switch 600 is closed in systems with multiple feedback cabinets. The system inrush current is avoided by closing the switches in stages.

[0124] When abnormal situation 4 (load regulation) occurs: Bus II loses voltage and there is no current. The device records the operating current and load rate of Bus I and Bus II before the voltage loss. The device trips switches 603 and 604 after a delay. The device calculates the load size of the low-voltage switches before the voltage loss and disconnects the tertiary loads. The number of circuits disconnected is calculated and determined by the preset load rate. After disconnecting switches 603 and 604, switches 600 and 603 are closed sequentially to restore power supply to the primary and secondary loads of the low-voltage system. After restoration, a second load regulation can be performed, and some tertiary loads can be restored as needed (the priority and load rate of the restored circuits can be set). The purpose of disconnecting switch 603 is to prevent multiple transformers from starting directly after switch 600 is closed in systems with multiple feedback cabinets. The system inrush current is avoided by closing the switches in stages.

[0125] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A control method for a multifunctional load regulating backup power switching device, characterized in that, This control method monitors the operation and load rate of the high-voltage system online, and controls the opening and closing of each switch in case of a fault. It adjusts and controls the low-voltage load of multiple circuits to keep the load rate within the range that the high-voltage system can withstand. Then, it switches to the backup power supply and makes secondary adjustments based on the load rate to restore the low-voltage load operation. The control method includes the following steps: S1. Online detection and judgment of whether the backup automatic transfer meets the charging conditions, and when the charging conditions are met, the system performs a working power supply failure and voltage loss judgment. S2. When it is determined that the system has experienced a power supply failure and voltage loss, search for the fault type and fault area corresponding to the power supply failure and adaptively match the corresponding working mode. S3. Determine whether the working mode corresponding to the adaptive matching in S2 meets the discharge conditions, and if the discharge conditions are not met, start the automatic transfer switch and disconnect the switch associated with the working mode; S4. Determine whether the switch that tripped in S3 is in the open position, and after the switch trips to the open position, determine whether the fault area where the working power supply is de-voltaged is without voltage and without current, and execute the load shedding strategy when the fault area where the working power supply is de-voltaged is without voltage and without current. S5. After the load shedding strategy is successfully executed, the standby automatic transfer switch is activated; S6. Determine whether the corresponding standby automatic transfer switch of the working mode is in the closed position, and after confirming that the standby automatic transfer switch is in the closed position, execute the load connection strategy. S7. After the load input strategy is successfully executed, restore low-voltage load operation to the fault area where the working power supply has lost voltage.

2. The method according to claim 1, characterized in that, The load shedding strategy described in S4 includes: S41. Determine the fault type and fault area of ​​the power supply failure, and adaptively match the corresponding working mode; S42. At the instant of high-voltage side loss of voltage, record the number of low-voltage side loads of the downstream loads connected to the faulty power source. S43. Optimize the load shedding control strategy; S44. Detect the switching status of the faulty power source and the downstream loads connected to the faulty power source, and determine whether the load shedding strategy was successfully executed.

3. The method according to claim 2, characterized in that, The optimized load shedding control strategy described in S43 includes: direct shedding of high-voltage side loads and direct shedding of low-voltage side loads.

4. The method according to claim 3, characterized in that, The direct disconnection of the high-voltage side load includes: at the moment of high-voltage system failure, recording the load current when the low-voltage system fails, and selecting the low-voltage system switch to select the disconnection method by setting the low-voltage load rate; The direct disconnection of the low-voltage side load includes: cyclically scanning the downstream load and load importance, and disconnecting the three-level load switches with a load rate greater than a preset value during operation.

5. The method according to any one of claims 1-4, characterized in that, The execution of the load allocation strategy described in S6 includes: S61. Provide a backup automatic transfer switch; S62. Optimize the load control strategy based on the aforementioned automatic transfer switch; S63. Provide the high-voltage side feeder switch in sequence, and confirm that the high-voltage side feeder switch is in the closed position. Then, provide the low-voltage side incoming line switch and the low-voltage side feeder switch in sequence; otherwise, provide the low-voltage side tie switch and the low-voltage side backup power switch. S64. Detect the switching status of the faulty power source and the downstream loads connected to the faulty power source, and determine whether the load activation strategy was successfully executed.

6. The method according to claim 5, characterized in that, The optimized load control strategy described in S62 includes: At the moment of high voltage system failure, the high voltage system and low voltage system record the load current at the time of failure, and select the fast switching mode or the step-by-step switching mode of the high voltage system and low voltage system switches based on the set low voltage load rate. The low-voltage system is put into operation according to load type, and the three levels of low-voltage loads to be put into or taken out are determined based on the load size and importance. The high-voltage system delay and the low-voltage ATS delay settings are coordinated and completed.

7. A multifunctional load regulating backup power switching device based on the control method described in any one of claims 1-6, characterized in that, include: Acquisition module (100): used for online monitoring of the operation status and load rate of the high voltage system, specifically acquiring the switch and current signals of the high voltage side and the low voltage side, and based on the switch and current signals, monitoring the load rate of the bus and the load current and switch status of each low voltage circuit; And, logic control module (200): used to control the opening and closing of each switch according to the online monitoring of the high voltage system's operating status and load rate, and in the event of a fault.

8. The apparatus according to claim 7, characterized in that, The logic control module (200) includes: a model building unit (201): used for adaptive modeling of backup automatic switching based on the associated attributes of components in a dual-power system; First optimization unit (202): used to optimize the load control strategy and load shedding strategy based on the established standby self-start adaptive modeling; The second optimization unit (203) is used to adaptively optimize the standby self-start working mode based on the optimized load control strategy and the load cut-off control strategy. The discrimination unit (204) is used to determine the fault type and fault area of ​​the power supply undervoltage based on the optimized backup automatic transfer working mode. And, the matching and tracking unit (205): is used to match and control the automatic switching control strategy in real time based on the fault area and fault type.

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