A method and system for reverse power protection of microgrid based on new energy

Abstract

The present invention proposes a reverse power protection method and system based on a new energy microgrid, including the following steps: S1, real-time judgment on whether the city power is disconnected, if yes, proceed to S2, if no, maintain the current working state; S2, start the generator set to supply power, and then judge whether the output power of the new energy micro-station is greater than or equal to the power consumption of the load, if no, maintain the current working state and charge the energy storage unit, if yes, proceed to S3; S3, the generator set stops supplying power, and the energy storage unit serves as a temporary power supply to supply power to the load; S4, judge whether the output power of the new energy micro-station is greater than or equal to the power consumption of the load, if no, proceed to S5, if yes, maintain the current working state; S5, judge whether the power of the energy storage unit is less than or equal to the threshold, if yes, return to S2, if no, maintain the current working state. The present invention enables the emergency power supply vehicle to automatically adapt based on the reverse power of the distributed new energy micro-grid, reducing the waste of manpower and resources.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy microgrids, and in particular to a reverse power protection method and system based on new energy microgrids. Background Art

[0002] With the continuous introduction of national energy conservation and environmental protection policies, new energy sources such as solar energy and wind energy are becoming more and more widely used as a renewable, clean and pollution-free energy source. However, small-scale grid-connected new energy sources cannot independently supply power when the city power is cut off.

[0003] At present, people have higher and higher requirements for power supply. While ensuring the quality of power supply, the stability of power supply has always been a concern for customers. Therefore, power supply reliability has become an important indicator for measuring the service quality of power supply companies. Emergency power supply vehicles, as mobile backup power stations, have been widely used in various industries and regions.

[0004] When the city power is cut off, photovoltaic power stations, hydropower stations and other new energy micro-power stations stop working, and residents are without power. At this time, emergency power supply vehicles are needed to supply electricity. After the emergency power supply vehicle is used as a power source, photovoltaic power stations, hydropower stations and other new energy micro-power stations start working again. At this time, if the power generation power of the new energy micro-power station is greater than the actual power used, the generator set on the emergency power supply vehicle will be treated as a motor, causing the generator set to shut down due to reverse power protection. After the shutdown and power outage, the new energy micro-power station stops working again, and the load is cut off again. At present, the solution to this problem is to shut down all new energy micro-power stations before using the emergency power supply vehicle, and then use the emergency power supply vehicle, and then put the new energy micro-power station into use after the city power is restored. This approach has caused a waste of manpower and resources. Summary of the invention

[0005] The present invention solves the problem that the reverse power protection shutdown of existing ordinary generator sets during temporary power supply causes long-term power outages in the region, and proposes a reverse power protection method and system based on a new energy microgrid, so that the emergency power supply vehicle can automatically adapt to the reverse power based on the distributed new energy microgrid, reducing the waste of manpower and resources.

[0006] In order to achieve the above objectives, the following technical solutions are proposed:

[0007] A reverse power protection method based on a new energy microgrid comprises the following steps:

[0008] S1, determine in real time whether the mains power is disconnected, if so proceed to S2, if not, maintain the current working state;

[0009] S2, start the generator set to supply power, and then determine whether the output power of the new energy micro-station is greater than or equal to the power consumption of the load. If not, keep the current working state and charge the energy storage unit. If so, proceed to S3;

[0010] S3, the generator set stops supplying power, and the energy storage unit serves as a temporary power source to supply power to the load;

[0011] S4, determine whether the output power of the new energy micro power station is greater than or equal to the power consumption of the load, if not, proceed to S5, if yes, maintain the current working state;

[0012] S5, determine whether the power of the energy storage unit is less than or equal to the threshold, if so, return to S2, if not, maintain the current working state.

[0013] The present invention can effectively prevent power interruption caused by reverse power protection shutdown of the generator set due to the new energy micro-power station on the load side during the entire power supply process; it is energy-saving and environmentally friendly, effectively utilizes resources and reduces manpower waste. The present invention can achieve good use effect in the power supply process.

[0014] A reverse power protection system based on a new energy microgrid is applicable to the above-mentioned reverse power protection method based on a new energy microgrid, comprising a generator set, a generator set output circuit breaker, a new energy micro power station, a mains power supply, a load and a reverse power protection device. The generator set is electrically connected to the reverse power protection device through the generator set output circuit breaker, the new energy micro power station, the mains power supply and the load are electrically connected to the reverse power protection device respectively, and the reverse power protection device, the new energy micro power station, the mains power supply and the load are connected for power supply.

[0015] The new energy micro power station, the mains power supply and the load are electrically connected to the reverse power protection device respectively, and the reverse power protection device is used to collect the power generation of the new energy micro power station and the mains power supply and the power consumption of the load. The reverse power protection device, the new energy micro power station, the mains power supply and the load power supply are connected, and the generator set can supply power to the load through the reverse power protection device, and the new energy micro power station and the mains power supply can supply power to the load at the same time. When the reverse power protection device collects the mains power supply power of 0, the mains power is cut off at this time, and the new energy micro-station also stops supplying power due to the mains power outage. The reverse power protection device closes the unit output circuit breaker to start the generator set. At this time, the generator set serves as a backup power source, and the new energy micro-station gradually starts to work. When the reverse power protection device detects that the power generation power of the new energy micro-station is less than the power consumption of the load, the generator set continues to supply power and stores part of the power in the reverse power protection device. The new energy micro-station detects that the power supply will continue to supply power; when the reverse power protection device detects that the power generation power of the new energy micro-station is greater than the power consumption of the load, the reverse power protection device disconnects the unit output circuit breaker and shuts down the generator set. At this time, the reverse power protection device is detected as a temporary power source by the new energy micro-station and can continue to supply power; thereafter, if the power generation power of the new energy micro-station gradually decreases and is less than the power consumption of the load, the reverse power protection device serves as a temporary power source to supply power. When it is detected that the electric energy stored in the reverse power protection device itself is insufficient, the reverse power protection device starts the generator set, closes the output circuit breaker of the generator set, and the generator set serves as a temporary power source to supply power. The present invention can effectively prevent the occurrence of power interruption due to reverse power protection shutdown of the generator set caused by the new energy micro-station on the load side during the entire power supply process; it is energy-saving and environmentally friendly, and effectively utilizes resources to reduce manpower waste. The present invention can achieve good use effects in the power supply process.

[0016] Preferably, the reverse power protection device comprises:

[0017] A control unit, wherein the control unit is electrically connected to the detection unit and the bidirectional converter, and the control unit is electrically connected to the generator set and the unit output circuit breaker;

[0018] A detection unit, one end of the unit output circuit breaker and one end of the bidirectional converter are connected in parallel to the detection unit, and the detection unit is electrically connected to the new energy micro power station, the mains power supply and the load;

[0019] A bidirectional converter, wherein the other end of the bidirectional converter is electrically connected to an energy storage unit.

[0020] When the mains power is cut off, when the detection unit collects the mains power power as 0, the new energy micro-station also stops supplying power due to the mains power outage. The control unit closes the unit output circuit breaker to start the generator set. At this time, the generator set serves as a backup power source, and the new energy micro-station gradually starts to work;

[0021] The detection unit collects the power generation of the new energy micro-station and the mains power supply, as well as the power consumption of the load. When the reverse power protection device detects that the power generation of the new energy micro-station is less than the power consumption of the load, the generator set continues to supply power and charges the energy storage unit through the bidirectional converter, storing part of the power in the reverse power protection device. The new energy micro-station detects that the power supply will continue to supply power;

[0022] When the detection unit detects that the power generation of the new energy micro-station is greater than the power consumption of the load, the control unit disconnects the unit output circuit breaker and shuts down the generator set. At this time, the energy storage unit is detected by the new energy micro-station as a temporary power source so that it can continue to supply power;

[0023] After that, if the power generation power of the new energy micro power station gradually decreases and is less than the power consumption of the load, the energy storage unit will supply power to the load as a temporary power source. When the detection unit detects that the energy storage unit is insufficient, the control unit starts the generator set and closes the output circuit breaker of the generator set, and the generator set serves as a temporary power source.

[0024] Preferably, the generator set and the reverse power protection device are arranged on the emergency power supply vehicle.

[0025] Preferably, the energy storage unit includes a lithium battery, a lead-acid battery and a power capacitor.

[0026] Preferably, the detection unit includes a switch W1, a switch W2, a switch W3, an operational amplifier Z1, an operational amplifier Z2, an operational amplifier Z3 and an operational amplifier Z4. The power signal sending end of the new energy micro power station is connected to the positive phase input end of the operational amplifier Z2 and the negative phase input end of the operational amplifier Z3 through the switch W1. The power signal sending end of the load is connected to the negative phase input end of the operational amplifier Z2 and the positive phase input end of the operational amplifier Z3 through the switch W2. The power signal sending end of the mains power supply is connected to the negative phase input end of the operational amplifier Z1. The positive phase input end of the operational amplifier Z1 is connected to a constant voltage V0. The output end of the operational amplifier Z1 is controlled and connected to the switches W1 and W2. When the operational amplifier Z1 outputs a high level, the switches W1 and W2 are closed. When the operational amplifier Z1 outputs a low level, the switches W1 and W2 are closed. The switch W2 is turned on, the output end of the operational amplifier Z1 is connected to the control unit, the bidirectional converter is connected to the reverse phase input end of the operational amplifier Z4 through the switch W3, the output end of the operational amplifier Z3 is control-connected to the switch W3, when the operational amplifier Z3 outputs a high level, the switch W3 is turned off, when the output of the operational amplifier Z3 is a low level, the switch W3 is turned on, the positive phase input end of the operational amplifier Z4 is connected to the constant voltage V1, the output end of the operational amplifier Z4 is connected to the control unit, the generator set has a built-in starting switch W0, the control unit is control-connected to the starting switch W0 and the unit output circuit breaker, when the control unit receives only one high level or two low level signals, the switch W0 and the unit output circuit breaker are controlled to be opened, when the control unit receives one low level and one high level, the control unit controls the switch W0 and the unit output circuit breaker to be closed.

[0027] Preferably, the constant voltage V0 has a value range of 0.01V to 1V.

[0028] Preferably, the constant voltage V1 has a value range of 0.2V3 to 0.3V3, where V3 is the normal operating voltage of the energy storage unit.

[0029] The beneficial effects of the present invention are: the present invention can effectively prevent the occurrence of power interruption caused by the reverse power protection shutdown of the generator set caused by the new energy micro-power station on the load side during the entire power supply process; and it is energy-saving and environmentally friendly, and effectively utilizes resources to reduce manpower waste. The present invention can achieve good use effects in the process of power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of the system structure of Example 2;

[0031] Figure 2 is a schematic structural diagram of a detection unit of Example 3;

[0032] Among them: 1. Generator set; 2. Control unit; 3. Unit output circuit breaker; 4. Bidirectional converter; 5. Energy storage unit; 6. Detection unit; 7. Mains power supply; 8. New energy micro power station; 9. Load. DETAILED DESCRIPTION

[0033] Embodiment 1:

[0034] This embodiment proposes a reverse power protection method based on a new energy microgrid, including the following steps:

[0035] S1, determine in real time whether the mains power is disconnected, if so proceed to S2, if not, maintain the current working state;

[0036] S2, start the generator set to supply power, and then determine whether the output power of the new energy micro-station is greater than or equal to the power consumption of the load. If not, keep the current working state and charge the energy storage unit. If so, proceed to S3;

[0037] S3, the generator set stops supplying power, and the energy storage unit serves as a temporary power source to supply power to the load;

[0038] S4, determine whether the output power of the new energy micro power station is greater than or equal to the power consumption of the load, if not, proceed to S5, if yes, maintain the current working state;

[0039] S5, determine whether the power of the energy storage unit is less than or equal to the threshold, if so, return to S2, if not, maintain the current working state.

[0040] This embodiment also proposes a reverse power protection system based on a new energy microgrid, which is applicable to the above-mentioned reverse power protection method based on a new energy microgrid, including a generator set 1, a generator set output circuit breaker 3, a new energy micro power station 8, a mains power supply 7, a load 9 and a reverse power protection device. The generator set 1 is electrically connected to the reverse power protection device through the generator set output circuit breaker 3, and the new energy micro power station 8, the mains power supply 7 and the load 9 are electrically connected to the reverse power protection device respectively. The reverse power protection device, the new energy micro power station 8, the mains power supply 7 and the load 9 are connected for power supply. The generator set 1 and the reverse power protection device are arranged on the emergency power supply vehicle. The new energy micro power station 8, the mains power supply 7 and the load 9 are electrically connected to the reverse power protection device respectively. At this time, the reverse power protection device is used to collect the power generation of the new energy micro power station 8 and the mains power supply 7 and the power consumption of the load 9. The reverse power protection device, the new energy micro power station 8, the mains power supply 7 and the load 9 are connected for power supply. The generator set 1 can supply power to the load 9 through the reverse power protection device, and the new energy micro power station 8 and the mains power supply 7 can supply power to the load 9 at the same time. When the reverse power protection device collects the power of the mains power supply 7 as 0, the mains power is cut off at this time, and the new energy micro power station 8 also stops supplying power due to the mains power outage. The reverse power protection device closes the unit output circuit breaker 3 to start the generator set 1. At this time, the generator set 1 serves as a backup power supply, and the new energy micro power station 8 gradually starts to work. When the reverse power protection device detects that the power generation power of the new energy micro power station 8 is less than the power consumption of the load 9, the generator set 1 continues to supply power and stores part of the power in the reverse power protection device. The new energy micro power station 8 detects that the power supply will continue to supply power; when the reverse power protection device detects that the power generation power of the new energy micro power station 8 is greater than the power consumption of the load 9, the reverse power protection device disconnects the unit output circuit breaker 3 and turns off the generator set 1. At this time, the reverse power protection device is detected by the new energy micro power station 8 as a temporary power supply and can continue to supply power; thereafter, if the power generation power of the new energy micro power station 8 gradually decreases and is less than the power consumption of the load 9, the reverse power protection device serves as a temporary power supply to supply power. When it is detected that the electric energy stored in the reverse power protection device itself is insufficient, the reverse power protection device starts the generator set 1, closes the output circuit breaker 3 of the generator set, and the generator set 1 serves as a temporary power supply to supply power. The present invention can effectively prevent the occurrence of power interruption due to reverse power protection shutdown of the generator set caused by the new energy micro-station on the load side during the entire power supply process; it is energy-saving and environmentally friendly, and effectively utilizes resources to reduce manpower waste. The present invention can achieve good use effects in the power supply process.

[0041] Embodiment 2:

[0042] This embodiment designs a reverse power protection device based on the embodiment 1, and the reverse power protection device includes:

[0043] A control unit 2, the control unit 2 is electrically connected to a detection unit 6 and a bidirectional converter 4, and the control unit 2 is electrically connected to the generator set 1 and the unit output circuit breaker 3;

[0044] The detection unit 6, one end of the unit output circuit breaker 3 and one end of the bidirectional converter 4 are connected in parallel to the detection unit 6, and the detection unit 6 new energy micro power station 8, the mains power supply 7 and the load 9 are electrically connected;

[0045] The other end of the bidirectional converter 4 is electrically connected to an energy storage unit 5. The energy storage unit includes a lithium battery, a lead-acid battery and a power capacitor.

[0046] When the mains power supply 7 is powered off, when the detection unit 6 collects that the power of the mains power supply 7 is 0, the new energy micro power station 8 also stops supplying power due to the mains power outage, and the control unit 2 closes the unit output circuit breaker 3 to start the generator set 1. At this time, the generator set 1 serves as a backup power source, and the new energy micro power station 8 gradually starts to work;

[0047] The detection unit 6 collects the power generation of the new energy micro-station 8 and the mains power supply 7 and the power consumption of the load 9. When the reverse power protection device detects that the power generation of the new energy micro-station 8 is less than the power consumption of the load 9, the generator set 1 continues to supply power and charges the energy storage unit 5 through the bidirectional converter 4, and stores part of the power in the reverse power protection device. The new energy micro-station 8 detects that the power supply will continue to supply power;

[0048] When the detection unit 6 detects that the power generation of the new energy micro-station 8 is greater than the power consumption of the load 9, the control unit 2 disconnects the unit output circuit breaker 3 and shuts down the generator set 1. At this time, the energy storage unit 5 is detected by the new energy micro-station 8 as a temporary power source so that it can continue to supply power;

[0049] Thereafter, if the power generation power of the new energy micro power station 8 gradually decreases and is less than the power consumption of the load 9, the energy storage unit 5 supplies power to the load 9 as a temporary power source. When the detection unit 6 detects that the energy storage unit 5 is insufficient, the control unit 2 starts the generator set 1 and closes the output circuit breaker 3 of the generator set, and the generator set 1 supplies power as a temporary power source.

[0050] Embodiment 3:

[0051] This embodiment designs a detection unit based on embodiment 2. Figure 2The detection unit 6 includes a switch W1, a switch W2, a switch W3, an operational amplifier Z1, an operational amplifier Z2, an operational amplifier Z3 and an operational amplifier Z4. The power signal sending end of the new energy micro power station 8 is connected to the positive phase input end of the operational amplifier Z2 and the negative phase input end of the operational amplifier Z3 through the switch W1. The power signal sending end of the load 9 is connected to the negative phase input end of the operational amplifier Z2 and the positive phase input end of the operational amplifier Z3 through the switch W2. The power signal sending end of the mains power supply 7 is connected to the negative phase input end of the operational amplifier Z1. The positive phase input end of the operational amplifier Z1 is connected to a constant voltage V0. The output end of the operational amplifier Z1 is controlled and connected with the switch W1 and the switch W2. When the output of the operational amplifier Z1 is high level, the switch W1 and the switch W2 are closed. When the output of the operational amplifier Z1 is low level, the switch W1 and the switch W2 are closed. The output of the operational amplifier Z1 is connected to the control unit 2. The bidirectional converter 4 is connected to the reverse phase input of the operational amplifier Z4 through the switch W3. The output of the operational amplifier Z3 is controlled and connected with the switch W3. When the operational amplifier Z3 outputs a high level, the switch W3 is closed. When the operational amplifier Z3 outputs a low level, the switch W3 is opened. The positive phase input of the operational amplifier Z4 is connected with the constant voltage V1. The output of the operational amplifier Z4 is connected to the control unit 2. The generator set 1 has a built-in start switch W0. The control unit 2 is controlled and connected with the start switch W0 and the unit output circuit breaker 3. When the control unit 2 receives only one high level or two low level signals, the switch W0 and the unit output circuit breaker 3 are controlled to be opened. When the control unit 2 receives one low level and one high level, the control unit 2 controls the switch W0 and the unit output circuit breaker 3 to be closed. The value range of the constant voltage V0 is 0.01V to 1V. The value range of the constant voltage V1 is between 0.2V3 and 0.3V3. V3 is the normal working voltage of the energy storage unit 5.

[0052] When the mains power supply 7 is disconnected, the control unit 2 controls the start switch W0 and the unit output circuit breaker 3 to close. At this time, it can be determined that the voltage at the power signal sending end of the mains power supply 7 is 0, which is less than the constant voltage V0. At this time, the output end of the operational amplifier Z1 outputs a high level, and switches W1 and W2 are closed, and the next step of judgment is performed; when the output power of the new energy micro-station 8 is greater than or equal to the actual output power of the load 9, that is, the voltage at the power signal sending end of the new energy micro-station 8 is higher than the voltage at the power signal sending end of the load 9, the output end of the operational amplifier Z2 outputs a high level to the control unit 2, and the output end of the operational amplifier Z3 outputs a low level, switch W3 is opened, and the control unit 2 only receives 1 high level, controls the switch W0 and the unit output circuit breaker 3 to open, and at this time the control unit 2 controls the bidirectional converter 4 to invert, so that the energy storage unit 5 discharges as a backup voltage, when the output power of the new energy micro-station 8 is less than the load 9 9 actual output power, that is, the voltage at the power signal sending end of the new energy micro power station 8 is lower than the voltage at the power signal sending end of the load 9, the output end of the operational amplifier Z2 outputs a low level to the control unit 2, the output end of the operational amplifier Z3 outputs a high level, and the switch W3 is closed. At this time, the inverting input end of the operational amplifier Z4 can receive the output voltage of the energy storage unit 5, and judge the output voltage of the energy storage unit 5 and the constant voltage V1. If the output voltage of the energy storage unit 5 is greater than the constant voltage V1, the operational amplifier Z4 outputs a low level to the control unit 2. At this time, the control unit 2 receives two low levels, and the control unit 2 controls the switch W0 and the unit output circuit breaker 3 to open. If the output voltage of the energy storage unit 5 is less than the constant voltage V1, the operational amplifier Z4 outputs a high level to the control unit 2. At this time, the control unit 2 receives 1 low level and 1 high level, and the control unit 2 controls the switch W0 and the unit output circuit breaker 3 to close.

Claims

1. A reverse power protection method based on new energy microgrid, characterized in that: The following steps are involved: S1, determine in real time whether the mains is disconnected. If so, the new energy micro power station stops working and proceeds to S2. If not, maintain the current working state; S2, start the generator set to supply power, the new energy micro power station starts working again, and then judge whether the output power of the new energy micro power station is greater than or equal to the power consumption of the load. If not, keep the current working state and charge the energy storage unit. If so, proceed to S3; S3, the generator set stops supplying power, and the energy storage unit serves as a temporary power source to supply power to the load; S4, determine whether the output power of the new energy micro power station is greater than or equal to the power consumption of the load, if not, proceed to S5, if yes, maintain the current working state; S5, determine whether the power of the energy storage unit is less than or equal to the threshold, if so, return to S2, if not, maintain the current working state.

2. A reverse power protection system based on a new energy microgrid, applicable to a reverse power protection method based on a new energy microgrid as described in claim 1, characterized in that: The invention comprises a generator set (1), a generator set output circuit breaker (3), a new energy micro power station (8), a mains power supply (7), a load (9) and a reverse power protection device, wherein the generator set (1) is electrically connected to the reverse power protection device via the generator set output circuit breaker (3), the new energy micro power station (8), the mains power supply (7) and the load (9) are electrically connected to the reverse power protection device respectively, and the reverse power protection device, the new energy micro power station (8), the mains power supply (7) and the load (9) are connected for power supply.

3. According to claim 2, a reverse power protection system based on a new energy microgrid is characterized in that: The reverse power protection device comprises: A control unit (2), the control unit (2) being electrically connected to a detection unit (6) and a bidirectional converter (4), and the control unit (2) being electrically connected to a generator set (1) and a generator set output circuit breaker (3); A detection unit (6), one end of the unit output circuit breaker (3) and one end of the bidirectional converter (4) are connected in parallel to the detection unit (6), and the detection unit (6), the new energy micro power station (8), the mains power supply (7) and the load (9) are electrically connected; A bidirectional converter (4), wherein the other end of the bidirectional converter (4) is electrically connected to an energy storage unit (5).

4. A reverse power protection system based on a new energy microgrid according to claim 2 or 3, characterized in that: The generator set (1) and the reverse power protection device are arranged on the emergency power supply vehicle.

5. According to claim 3, a reverse power protection system based on a new energy microgrid is characterized in that: The energy storage unit includes a lithium battery, a lead-acid battery and a power capacitor.

6. The reverse power protection system based on new energy microgrid according to claim 3 is characterized in that: The detection unit (6) comprises a switch W1, a switch W2, a switch W3, an operational amplifier Z1, an operational amplifier Z2, an operational amplifier Z3 and an operational amplifier Z4. The power signal sending end of the new energy micro power station (8) is connected to the positive phase input end of the operational amplifier Z2 and the negative phase input end of the operational amplifier Z3 through the switch W1. The power signal sending end of the load (9) is connected to the negative phase input end of the operational amplifier Z2 and the positive phase input end of the operational amplifier Z3 through the switch W2. The power signal sending end of the mains power supply (7) is connected to the negative phase input end of the operational amplifier Z1. The positive phase input end of the operational amplifier Z1 is connected to a constant voltage V0. The output end of the operational amplifier Z1 is controlled and connected to the switch W1 and the switch W2. When the output of the operational amplifier Z1 is high level, the switch W1 and the switch W2 are closed. When the output of the operational amplifier Z1 is low level, the switch W1 and the switch W2 are opened. The output end of the bidirectional converter (4) is connected to the reverse phase input end of the operational amplifier Z4 through the switch W3. The output end of the operational amplifier Z3 is control-connected to the switch W3. When the operational amplifier Z3 outputs a high level, the switch W3 is closed. When the operational amplifier Z3 outputs a low level, the switch W3 is opened. The positive phase input end of the operational amplifier Z4 is connected to a constant voltage V1. The output end of the operational amplifier Z4 is connected to the control unit (2). The generator set (1) has a built-in start switch W0. The control unit (2) is control-connected to the start switch W0 and the set output circuit breaker (3). When the control unit (2) receives only one high level signal or two low level signals, the switch W0 and the set output circuit breaker (3) are controlled to be opened. When the control unit (2) receives one low level and one high level signal, the control unit (2) controls the switch W0 and the set output circuit breaker (3) to be closed.

7. The reverse power protection system based on new energy microgrid according to claim 6 is characterized in that: The constant voltage V0 has a value range of 0.01V to 1V.

8. The reverse power protection system based on new energy microgrid according to claim 6 is characterized in that: The constant voltage V1 has a value range of 0.2V3 to 0.3V3, and V3 is the normal operating voltage of the energy storage unit (5).

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