Voltage treatment and reliable power supply guarantee system

Abstract

The invention relates to a voltage treatment and reliable power supply guarantee system, which comprises a hybrid supercapacitor energy storage unit; the direct current side of the converter unit is connected with the hybrid supercapacitor energy storage unit, the alternating current side of the converter unit is connected with a system main loop, and the converter unit is used for realizing charging and discharging operation of the hybrid supercapacitor energy storage unit; the power supply switching unit is arranged on the system main loop and is used for switching a power supply of a load between an alternating current power grid and the hybrid supercapacitor energy storage unit; and the measurement and control unit is used for collecting measurement data, monitoring and analyzing the state of the whole system according to the measurement data, and performing coordination control on the whole system based on an analysis result. According to the invention, high-quality and high-reliability power supply of important sensitive loads can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of power quality management, and in particular to a voltage management and reliable power supply guarantee system. Background Art

[0002] With the continuous development of my country's socio-economic and manufacturing sectors, power quality has become a significant concern for both power companies and users. Voltage sags are considered one of the most significant power quality issues impacting the normal and safe operation of various types of electrical equipment. In recent years, users have increasingly demanded higher standards for power supply quality and reliability. Industries like semiconductors, petrochemicals, precision machining, and advanced manufacturing are particularly demanding, as their critical production loads place stringent demands on power quality and reliability. Voltage sags / swells or short-term power outages can cause downtime or even damage to critical production equipment, resulting in significant economic losses for users.

[0003] Currently, voltage sag management generally uses systematic, customized solutions, with key technical approaches categorized as: dynamic voltage restorers (DVRs), uninterruptible power supplies (UPSs), and fast voltage regulators. However, these approaches all have drawbacks: DVRs use conventional supercapacitors as energy storage units, which are costly and bulky, typically have short storage times (1-3 seconds), and lack the ability to maintain voltage for extended periods or withstand short power outages; UPSs occupy a large footprint, experience significant operating losses, and incur high maintenance costs; and fast voltage regulators can only compensate for voltage sags within a narrow range (generally no more than 30% of the rated voltage), making them incapable of managing voltage in extreme conditions such as larger voltage drops and short power outages. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a voltage management and reliable power supply guarantee system, which can achieve high-quality and highly reliable power supply for important sensitive loads.

[0005] The technical solution adopted by the present invention to solve the technical problem is to provide a voltage control and reliable power supply guarantee system, including:

[0006] Hybrid supercapacitor energy storage unit;

[0007] A converter unit, the DC side of which is connected to the hybrid supercapacitor energy storage unit and the AC side of which is connected to the main circuit of the system, wherein the converter unit is used to realize the charging and discharging operation of the hybrid supercapacitor energy storage unit;

[0008] A power switching unit, provided on the main circuit of the system, for switching the power supply of the load between the AC power grid and the hybrid supercapacitor energy storage unit;

[0009] The measurement and control unit is used to collect measurement data, monitor and analyze the status of the entire system based on the measurement data, and coordinate and control the entire system based on the analysis results.

[0010] The conversion unit includes a converter and a transformer. The DC end of the converter is connected to the hybrid supercapacitor energy storage unit, the AC end is connected to one side of the transformer, and the other side of the transformer is connected to the main circuit of the system. When the converter is in grid-connected operation, the converter charges the hybrid supercapacitor energy storage unit according to the voltage and frequency of the AC power grid. When the converter is in off-grid operation, the converter discharges the hybrid supercapacitor energy storage unit and establishes a stable voltage and frequency to supply power to the load.

[0011] The power switching unit includes a solid-state circuit breaker, which is used to achieve rapid disconnection and accurate control of the disconnection moment, and can achieve seamless switching of the power supply for the load between the AC power grid and the hybrid supercapacitor energy storage unit.

[0012] The voltage management and reliable power supply guarantee system also includes a bypass unit, which is connected in parallel at both ends of the power switching unit and is used to temporarily bypass the system main circuit and temporarily power the load when the system is maintained; the power switching unit also includes an incoming switch and an outgoing switch, the incoming switch is arranged between the solid-state circuit breaker and the AC power grid, and the outgoing switch is arranged between the solid-state circuit breaker and the load.

[0013] The bypass unit includes a bypass switch. When the system needs maintenance and overhaul, the bypass switch is closed, and the incoming switch and the outgoing switch are both opened; when the system completes maintenance and overhaul, the bypass switch is opened, and the incoming switch and the outgoing switch are both closed.

[0014] The hybrid supercapacitor energy storage unit is composed of a plurality of hybrid supercapacitor modules connected in series and in parallel, and each hybrid supercapacitor module is composed of a plurality of hybrid supercapacitor monomers connected in series and in parallel.

[0015] The measurement data includes: voltage and frequency information of the AC power grid, charge state information of the hybrid supercapacitor energy storage unit, operating state information of the converter unit, and operating state information of the power switching unit.

[0016] The measurement and control unit includes:

[0017] A power supply voltage determination unit, configured to determine whether the power supply voltage is normal based on the collected voltage and frequency information of the AC power grid;

[0018] A first execution unit is configured to control the solid-state circuit breaker of the power switching unit to be turned on when the power supply voltage is normal, and simultaneously control the converter in the conversion unit to float charge the hybrid supercapacitor energy storage unit;

[0019] The second execution unit is used to control the solid-state circuit breaker of the power switching unit to disconnect when the power supply voltage is abnormal, and at the same time control the converter in the converter unit to output a standard compensation voltage.

[0020] The measurement and control unit also includes:

[0021] a discharge cutoff judgment unit, configured to judge whether the hybrid supercapacitor energy storage unit has reached a discharge cutoff condition based on the collected state of charge information of the hybrid supercapacitor energy storage unit;

[0022] a third execution unit, configured to disconnect the incoming switch of the power switching unit and stop the converter from discharging the hybrid supercapacitor energy storage unit when the hybrid supercapacitor energy storage unit reaches a discharge cut-off condition;

[0023] a charging cutoff judgment unit, configured to judge whether the hybrid supercapacitor energy storage unit has reached a charging cutoff condition when the hybrid supercapacitor energy storage unit has not reached a discharging cutoff condition;

[0024] a fourth execution unit, configured to control the converter to be in a hot standby state when the hybrid supercapacitor energy storage unit reaches a charging cut-off condition;

[0025] The fifth execution unit is configured to control the converter to perform float charging on the hybrid supercapacitor energy storage unit when the hybrid supercapacitor energy storage unit does not meet the charging cut-off condition.

[0026] The measurement and control unit also includes:

[0027] A bypass switch state determination unit, configured to determine whether the bypass switch is in a closed state;

[0028] a sixth execution unit, configured to control the solid-state circuit breaker of the power switching unit to be disconnected, and simultaneously control the incoming switch and the outgoing switch of the power switching unit to be disconnected when the bypass switch is in a closed state;

[0029] The seventh execution unit is used to control the solid-state circuit breaker of the power switching unit to be turned on when the bypass switch is not in a closed state, and at the same time control the incoming switch and the outgoing switch of the power switching unit to be closed.

[0030] Beneficial effects

[0031] Due to the adoption of the above-mentioned technical solution, the present invention has the following advantages and positive effects compared with the prior art: the present invention adopts a hybrid ultracapacitor (HUC) energy storage to construct a new type of voltage control and reliable power supply guarantee system, which has the advantages of small footprint, fast response speed, wide control range, long support time, and long service life. It can achieve continuous control of minute-level voltage sags and short-term emergency power supply support, and can provide high-quality power supply guarantee for important sensitive loads, significantly improving users' sense of gain and the level of power supply quality control and guarantee. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural diagram of the voltage management and reliable power supply guarantee system according to the embodiment of the present invention. DETAILED DESCRIPTION

[0033] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0034] The first embodiment of the present invention relates to a voltage management and reliable power supply guarantee system, such as Figure 1 As shown, it includes a hybrid supercapacitor energy storage unit, a current conversion unit, a power switching unit and a measurement and control unit.

[0035] The hybrid ultracapacitor (HUC) energy storage unit consists of multiple hybrid ultracapacitor modules connected in series and parallel. Each hybrid ultracapacitor module is composed of multiple hybrid ultracapacitor monomers connected in series and parallel, and serves as the energy storage unit for the entire system. In specific applications, the energy storage time of the hybrid ultracapacitor energy storage unit is recommended to be configured according to 3 to 6 minutes. If the user requires a longer power supply guarantee time, the energy storage time of the hybrid ultracapacitor energy storage unit can be increased as needed, but the configuration time generally does not exceed 15 minutes.

[0036] The hybrid supercapacitor in this embodiment is a new type of energy storage device between a supercapacitor and a secondary battery. It combines the advantages of supercapacitors and batteries, has both high power density and energy density, and its energy-to-power ratio is more optimized, with high charge and discharge rates and efficiency, long cycle life (up to tens of thousands of times), and a wide operating temperature range (-40°C to +60°C). It is very suitable for voltage management and short-term power supply support, which are scenarios with high requirements for energy storage density and power performance. The hybrid supercapacitor energy storage unit used, based on the high energy density and high power density of the hybrid supercapacitor, can achieve continuous management and short-term power supply support for voltage sags and swells at the minute level without significantly increasing the volume and floor space of the energy storage unit, greatly improving the time and capacity of management and support, while having a long service life, and can effectively solve the problems and impacts of voltage sags, swells, short-term power supply interruptions, etc. on users' important sensitive loads.

[0037] The DC side of the converter unit is connected to the hybrid supercapacitor energy storage unit, and the AC side is connected to the main circuit of the system. The converter unit is used to realize the charging and discharging operation of the hybrid supercapacitor energy storage unit. The converter unit in this embodiment includes a transformer and a converter, wherein the transformer is mainly used to realize the conversion between the AC port voltage of the converter and the AC grid voltage; the converter is mainly used to realize the conversion between the DC power and AC power of the hybrid supercapacitor energy storage unit, and its DC port voltage range matches the output voltage range of the hybrid supercapacitor energy storage unit, and the AC port voltage matches the voltage of the transformer to which it is connected. Through grid-connected / off-grid operation control, the hybrid supercapacitor energy storage unit is charged according to the voltage and frequency of the grid in the case of grid-connected operation, and the hybrid supercapacitor energy storage unit is discharged in the case of off-grid operation, and a stable voltage and frequency are established to provide external power supply support. In specific applications, the converter can adopt a bidirectional DC / AC converter, whose rated power capacity is determined according to not less than 1.5 times the maximum power of the important sensitive load to be protected, and the rated power capacity of the transformer is determined according to not less than the rated power capacity of the converter.

[0038] The power switching unit in this embodiment is disposed on the system's main circuit and is used to switch the load's power supply between the AC power grid and the hybrid supercapacitor energy storage unit. The power switching unit includes a solid-state circuit breaker, which is designed to achieve rapid disconnection and precise control of disconnection timing, enabling seamless switching of the power supply for critical sensitive loads between the AC power grid and the hybrid supercapacitor energy storage unit. In specific applications, the solid-state circuit breaker can utilize a fully controlled IGBT to control its on and off states, with its disconnection capacity determined to be no less than 1.5 times the maximum power of the critical sensitive load being protected.

[0039] The measurement and control unit in this embodiment is used to collect measurement data, monitor and analyze the status of the entire system based on the measurement data, and coordinate and control the entire system based on the analysis results, thereby realizing the system's management of voltage sags, swells, short-term power interruptions, etc., to ensure high-quality power supply to important sensitive loads. Among them, the collected measurement data include: the voltage amplitude and frequency on the AC grid side, the charge state of the hybrid supercapacitor energy storage unit, the operating state of the converter unit, and the operating state of the power switching unit. Among them, the operating status information of the converter unit mainly includes: converter operating power, converter DC port voltage, converter AC port voltage and frequency, transformer primary side voltage, transformer secondary side voltage, transformer operating power, etc. The operating status information of the power switching unit mainly includes: the on / off state of the solid-state circuit breaker. In specific applications, the data acquisition frequency of the measurement and control unit is generally configured to be no less than 10kHz.

[0040] It is worth mentioning that in order to achieve uninterrupted power supply maintenance and overhaul, the voltage control and reliable power supply guarantee system of this embodiment also includes a bypass unit. The bypass unit is connected in parallel at both ends of the power switching unit and is used to temporarily bypass the system main circuit and temporarily power the load when the system is under maintenance. To cooperate with the bypass unit, the power switching unit in this embodiment also includes an incoming switch and an outgoing switch. The incoming switch is arranged between the solid-state circuit breaker and the AC power grid, and the outgoing switch is arranged between the solid-state circuit breaker and the load. The bypass switch adopts a circuit breaker and has an automatic opening and closing function. When the system needs to be overhauled and maintained, the bypass switch is closed to switch to bypass operation. At the same time, the incoming switch and the outgoing switch are both disconnected, the system is isolated from the power supply line, and the important sensitive loads are powered by the AC power grid, so that the important sensitive loads can be overhauled without power outage. After the system maintenance is completed, the bypass switch can be disconnected, and the power supply is quickly switched to the AC power grid main circuit through the power switching unit, without affecting the normal operation of the important sensitive loads. In specific applications, the breaking capacity of the bypass switch is determined to be no less than 1.5 times the maximum power of the important sensitive load to be protected, and the breaking capacity of the incoming switch and the outgoing switch is also determined to be no less than 1.5 times the maximum power of the important sensitive load to be protected.

[0041] It can be seen that when the system needs to be inspected and maintained, it can be switched to bypass operation with one click. When the system detects that the bypass switch is closed, the solid-state circuit breaker is automatically shut down, the incoming switch and the outgoing switch are automatically disconnected, and important sensitive loads are powered by the AC power grid through the bypass circuit, which enables the system to be inspected and maintained without interrupting power to the load equipment. After the maintenance is completed, it can be restarted with one click, and the switch is seamless without affecting the load operation.

[0042] The measurement and control unit in this embodiment includes: a power supply voltage judgment unit, which is used to judge whether the power supply voltage is normal based on the collected voltage and frequency information of the AC power grid; a first execution unit, which is used to control the solid-state circuit breaker of the power switching unit to be turned on when the power supply voltage is normal, and at the same time control the converter in the converter unit to float charge the hybrid supercapacitor energy storage unit; a second execution unit, which is used to control the solid-state circuit breaker of the power switching unit to be turned off when the power supply voltage is abnormal, and at the same time control the converter in the converter unit to output a standard compensation voltage.

[0043] The measurement and control unit also includes: a discharge cut-off judgment unit, which is used to judge whether the hybrid supercapacitor energy storage unit has reached a discharge cut-off condition based on the collected charge state information of the hybrid supercapacitor energy storage unit; a third execution unit, which is used to disconnect the incoming switch of the power switching unit and stop the converter from discharging the hybrid supercapacitor energy storage unit when the hybrid supercapacitor energy storage unit reaches the discharge cut-off condition; a charge cut-off judgment unit, which is used to judge whether the hybrid supercapacitor energy storage unit has reached a charge cut-off condition when the hybrid supercapacitor energy storage unit has not reached the discharge cut-off condition; a fourth execution unit, which is used to control the converter to be in a hot standby state when the hybrid supercapacitor energy storage unit reaches the charge cut-off condition; and a fifth execution unit, which is used to control the converter to float charge the hybrid supercapacitor energy storage unit when the hybrid supercapacitor energy storage unit has not reached the charge cut-off condition.

[0044] The measurement and control unit also includes: a bypass status switch status judgment unit, used to judge whether the bypass switch is in a closed state; a sixth execution unit, used to control the solid-state circuit breaker of the power switching unit to be disconnected when the bypass switch is in a closed state, and at the same time control the incoming switch and the outgoing switch of the power switching unit to be disconnected; a seventh execution unit, used to control the solid-state circuit breaker of the power switching unit to be turned on when the bypass switch is not in a closed state, and at the same time control the incoming switch and the outgoing switch of the power switching unit to be closed.

[0045] The measurement and control unit based on the above structure can determine the working status of the entire system based on the measurement data, and issue relevant control instructions based on the system working status. The specific steps of the relevant control strategy are as follows:

[0046] Step 1: System initialization settings.

[0047] Step 2: Collect and update data information, including: voltage amplitude and frequency on the AC grid side, charge state of the hybrid supercapacitor energy storage unit, converter operating power, converter DC port voltage, converter AC port voltage and frequency, transformer primary side voltage, transformer secondary side voltage, transformer operating power, solid-state circuit breaker on / off status, incoming line switch on / off status, outgoing line switch on / off status, bypass switch on / off status, and other data information.

[0048] Step 3: Determine whether the bypass switch is in a closed state by the bypass switch state judgment unit. If the bypass switch is not in a closed state, proceed to step 4; if the bypass switch is in a closed state, proceed to step 9.

[0049] Step 4: The power supply voltage judgment unit determines whether the amplitude and frequency of the AC grid side voltage are within the set range of the amplitude and frequency of the important sensitive load power supply voltage, that is, determines whether the power supply voltage is normal. If the power supply voltage is normal, proceed to the next step; if the power supply voltage is abnormal, proceed to step 8.

[0050] Step 5: Determine whether the converter is in the discharge working state. If so, proceed to the next step. If not, determine that the system is in the conventional AC grid power supply operation mode, control the solid-state circuit breaker to be in the on state, and control the incoming and outgoing line switches to be in the closed state, and proceed to step 7.

[0051] Step 6: The discharge cutoff judgment unit determines whether the hybrid supercapacitor energy storage unit has reached the discharge cutoff condition. If the discharge cutoff condition is reached, the process proceeds to step 10. If the discharge cutoff condition is not reached, the converter output voltage phase is first controlled to match the AC grid voltage phase, and then the solid-state circuit breaker is controlled to conduct and stop the converter output. The important sensitive loads are switched to be powered by the AC grid, and the process proceeds to the next step.

[0052] Step 7: The charge cutoff determination unit determines whether the hybrid supercapacitor energy storage unit has reached the charge cutoff condition. If not, the converter is controlled to float charge the hybrid supercapacitor energy storage unit, and the process returns to step 2. If so, the converter is controlled to be in hot standby mode, and the entire system enters standby mode, and the process returns to step 2.

[0053] Step 8: Control the converter to output a standard compensation voltage, and at the same time control the solid-state circuit breaker to cut off the main power supply circuit of the AC power grid to ensure the stability of the power supply voltage of important sensitive loads, and return to step 2.

[0054] Step 9: Determine that the system is in the maintenance state, control the solid-state circuit breaker to turn off, and simultaneously control the incoming switch and the outgoing switch to be disconnected. At this time, the important sensitive loads are powered by the AC grid via the bypass, and return to step 2.

[0055] Step 10: Execute a protective shutdown operation, control the incoming line switch to be disconnected, and stop the converter from discharging the hybrid supercapacitor energy storage unit. Wait for the manual operation system to be put back into operation, and then return to step 1.

[0056] It is not difficult to find that this embodiment continuously monitors the voltage of the AC power grid. Once it is found that the power supply voltage is disturbed and cannot meet the power supply requirements of the user's important sensitive loads, the system can respond quickly, and output a standard compensation voltage to the important sensitive loads through the converter of the conversion unit, and at the same time quickly cut off the abnormal power supply on the AC power grid side based on the power switching unit; when it is monitored that the voltage on the AC power grid side returns to normal and meets the power supply requirements of the user's important sensitive loads, the system will automatically adjust the output phase of the converter to match the system voltage phase, turn on the thyristor and stop the converter output, and the important sensitive loads will be powered by the AC power grid again. After the hybrid supercapacitor energy storage unit is fully charged, the system enters the standby state, thereby achieving stable power supply voltage on the important sensitive load side and "zero perception" of voltage disturbances on the AC power grid side, and realizing multi-operating condition and wide range compensation for temporary voltage rises and dips.

Claims

1. A voltage management and reliable power supply guarantee system, characterized in that: include: Hybrid supercapacitor energy storage unit; The converter unit has a DC side connected to the hybrid supercapacitor energy storage unit and an AC side connected to the main circuit of the system. The current conversion unit is used to realize the charging and discharging operation of the hybrid supercapacitor energy storage unit; A power switching unit, provided on the main circuit of the system, for switching the power supply of the load between the AC power grid and the hybrid supercapacitor energy storage unit; The measurement and control unit is used to collect measurement data, monitor and analyze the status of the entire system based on the measurement data, and coordinate and control the entire system based on the analysis results.

2. The voltage management and reliable power supply guarantee system according to claim 1 is characterized in that: The conversion unit includes a converter and a transformer. The DC end of the converter is connected to the hybrid supercapacitor energy storage unit, the AC end is connected to one side of the transformer, and the other side of the transformer is connected to the main circuit of the system. When the converter is in grid-connected operation, the converter charges the hybrid supercapacitor energy storage unit according to the voltage and frequency of the AC power grid. When the converter is in off-grid operation, the converter discharges the hybrid supercapacitor energy storage unit and establishes a stable voltage and frequency to supply power to the load.

3. The voltage management and reliable power supply guarantee system according to claim 1, characterized in that: The power switching unit includes a solid-state circuit breaker, which is used to achieve rapid disconnection and accurate control of the disconnection moment, and can achieve seamless switching of the power supply for the load between the AC power grid and the hybrid supercapacitor energy storage unit.

4. The voltage management and reliable power supply guarantee system according to claim 3 is characterized in that: It also includes a bypass unit, which is connected in parallel at both ends of the power switching unit and is used to temporarily bypass the system main circuit and temporarily power the load when the system is maintained; the power switching unit also includes an incoming switch and an outgoing switch, the incoming switch is arranged between the solid-state circuit breaker and the AC power grid, and the outgoing switch is arranged between the solid-state circuit breaker and the load.

5. The voltage management and reliable power supply guarantee system according to claim 4 is characterized in that: The bypass unit includes a bypass switch. When the system needs maintenance and overhaul, the bypass switch is closed, and the incoming line switch and the outgoing line switch are both opened. When the system is maintained and overhauled, the bypass switch is disconnected, and both the incoming line switch and the outgoing line switch are closed.

6. The voltage management and reliable power supply guarantee system according to claim 1, characterized in that: The hybrid supercapacitor energy storage unit is composed of a plurality of hybrid supercapacitor modules connected in series and in parallel, and each hybrid supercapacitor module is composed of a plurality of hybrid supercapacitor monomers connected in series and in parallel.

7. The voltage management and reliable power supply guarantee system according to claim 1, characterized in that: The measurement data includes: voltage and frequency information of the AC power grid, charge state information of the hybrid supercapacitor energy storage unit, operating state information of the converter unit, and operating state information of the power switching unit.

8. The voltage management and reliable power supply guarantee system according to claim 1, characterized in that: The measurement and control unit includes: A power supply voltage determination unit, configured to determine whether the power supply voltage is normal based on the collected voltage and frequency information of the AC power grid; A first execution unit is configured to control the solid-state circuit breaker of the power switching unit to be turned on when the power supply voltage is normal, and simultaneously control the converter in the conversion unit to float charge the hybrid supercapacitor energy storage unit; The second execution unit is used to control the solid-state circuit breaker of the power switching unit to disconnect when the power supply voltage is abnormal, and at the same time control the converter in the converter unit to output a standard compensation voltage.

9. The voltage management and reliable power supply guarantee system according to claim 1, characterized in that: The measurement and control unit also includes: a discharge cutoff judgment unit, configured to judge whether the hybrid supercapacitor energy storage unit has reached a discharge cutoff condition based on the collected state of charge information of the hybrid supercapacitor energy storage unit; a third execution unit, configured to disconnect the incoming switch of the power switching unit and stop the converter from discharging the hybrid supercapacitor energy storage unit when the hybrid supercapacitor energy storage unit reaches a discharge cut-off condition; a charging cutoff judgment unit, configured to judge whether the hybrid supercapacitor energy storage unit has reached a charging cutoff condition when the hybrid supercapacitor energy storage unit has not reached a discharging cutoff condition; a fourth execution unit, configured to control the converter to be in a hot standby state when the hybrid supercapacitor energy storage unit reaches a charging cut-off condition; The fifth execution unit is configured to control the converter to perform float charging on the hybrid supercapacitor energy storage unit when the hybrid supercapacitor energy storage unit does not meet the charging cut-off condition.

10. The voltage management and reliable power supply guarantee system according to claim 5, characterized in that: The measurement and control unit also includes: A bypass switch state determination unit, configured to determine whether the bypass switch is in a closed state; a sixth execution unit, configured to control the solid-state circuit breaker of the power switching unit to be disconnected, and simultaneously control the incoming switch and the outgoing switch of the power switching unit to be disconnected when the bypass switch is in a closed state; The seventh execution unit is used to control the solid-state circuit breaker of the power switching unit to be turned on when the bypass switch is not in a closed state, and at the same time control the incoming switch and the outgoing switch of the power switching unit to be closed.

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