A shunt tripping protection circuit and shunt tripping control method thereof

Abstract

The present invention provides a shunt tripping protection circuit and a shunt tripping control method thereof. By designing a shunt tripper into a hardware loop, the shunt tripper is connected in series with the normally closed contact of a first low-voltage relay and the normally open contact of a second low-voltage relay, and a normally open contact of a third low-voltage relay is added in parallel. In combination with an emergency stop switch, hardware control of the on-off of the first low-voltage relay coil is achieved, and the cooperation of an EMS system and an IO controller is achieved to control the on-off of the third low-voltage relay coil with software, thereby achieving hard and soft dual protection and realizing timely tripping of the shunt tripper under a storage system failure to avoid further danger.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage systems, and in particular to a shunt tripping protection circuit and a shunt tripping control method thereof. Background Art

[0002] As the central equipment of the energy storage system, the distribution cabinet is responsible for the power distribution of the energy storage system, and realizes operations such as starting, stopping and operating adjustment of electrical equipment, which helps to stabilize the operation of the energy storage system and meet the control requirements in various application scenarios.

[0003] The existing solution is to control the shunt release tripping by software: the IO controller controls the conduction of the relay, and then the shunt release trips. When a system fault is detected, the EMS system sends a command to the IO controller to output the corresponding control signal to trip the shunt release and open the main switch to protect the system.

[0004] However, there are several risks in soft control:

[0005] First, the timeliness issue. Due to the signal transmission and response time of the software system, there will be a certain delay between the tripping of the shunt release and the time when the fault occurs.

[0006] Second, when a power failure occurs in the system, the software system loses power and there is a risk that it will not be able to control the shunt release to trip in time;

[0007] In addition, if the control system itself fails, it may be impossible to issue a tripping command. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a shunt tripping protection circuit and a shunt tripping control method thereof, which can effectively ensure that the shunt tripping device can be controlled to trip in time when a system failure occurs to avoid further danger.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0010] A shunt tripping protection circuit comprises an emergency stop button, an IO controller, a shunt tripper, a first low voltage relay, a second low voltage relay, a third low voltage relay and an EMS system connected to the IO controller for communication and control;

[0011] The IO controller is powered by a first power supply, and the shunt release is powered by a second power supply;

[0012] The emergency stop button is connected to the first low-voltage relay and the IO controller, controls the power supply of the first low-voltage relay and feeds back an emergency stop signal to the IO controller;

[0013] The IO controller connects and controls the power supply of the second low-voltage relay and the third low-voltage relay;

[0014] The shunt release, a normally closed contact of the first low-voltage relay, and a normally open contact of the second low-voltage relay are sequentially connected in series between the positive and negative electrodes of the second power supply;

[0015] One end of a normally open contact of the third low-voltage relay is connected between the shunt release and the normally closed contact of the first low-voltage relay, and the other end is connected to the negative electrode of the second power supply.

[0016] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0017] A shunt tripping control method adopts the above-mentioned shunt tripping protection circuit, and the EMS system performs the following control steps:

[0018] S1, determine whether the energy storage system fails, if so, proceed to step S2;

[0019] S2. Detect the level state of the IO input pin connected to the second emergency stop normally closed contact of the emergency stop button in the IO controller. If the level state is the first level, it is determined that the emergency stop button is pressed, the coil of the first low-voltage relay is de-energized to restore the normally closed contact of the first low-voltage relay to the normally closed state and cooperate with the closed normally open contact in the second low-voltage relay to energize and trip the shunt release, and disconnect the system main incoming line switch. At this time, the IO output pin connected to the coil of the third low-voltage relay in the IO controller is controlled to output the first level, so that both ends of the coil of the third low-voltage relay are energized, the normally open contact of the third low-voltage relay is closed, and the shunt release is kept energized and tripped.

[0020] The beneficial effects of the present invention are: providing a shunt tripping protection circuit and a shunt tripping control method thereof, by designing a shunt tripper into a hardware loop, connecting the shunt tripper in series with the normally closed contact of a first low-voltage relay and the normally open contact of a second low-voltage relay, and adding a normally open contact of a third low-voltage relay in parallel, and combining with an emergency stop switch to realize hardware control of the on-off of the first low-voltage relay coil, and the cooperation of an EMS system and an IO controller to realize software control of the on-off of the third low-voltage relay coil, thereby realizing hard and soft dual protection to realize timely tripping of the shunt tripper under a failure of an energy storage system to avoid further danger. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A circuit schematic diagram of a shunt tripping protection circuit according to an embodiment of the present invention;

[0022] Figure 2The present invention is a flowchart of a shunt tripping control method according to an embodiment of the present invention.

[0023] Description of labels:

[0024] 10. EMS system; 20. IO controller; KA1. coil of the first low-voltage relay; KA1_1. normally closed contact of the first low-voltage relay; KA2. coil of the second low-voltage relay; KA2_1. normally open contact of the second low-voltage relay; KA3. coil of the third low-voltage relay; KA3_1. normally open contact of the third low-voltage relay; MX. shunt release; SB_1. first emergency stop normally closed contact; SB_2. second emergency stop normally closed contact. DETAILED DESCRIPTION

[0025] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0026] Please refer to Figure 1 , a shunt trip protection circuit, comprising an emergency stop button, an IO controller, a shunt trip, a first low voltage relay, a second low voltage relay and an EMS system connected to the IO controller for communication and control;

[0027] The IO controller is powered by a first power supply, and the shunt release is powered by a second power supply;

[0028] The emergency stop button includes a first emergency stop normally closed contact and a second emergency stop normally closed contact, the first emergency stop normally closed contact and the coil of the first low-voltage relay are connected in series between the positive and negative electrodes of the first power supply, and the second emergency stop normally closed contact is connected in series between the IO controller and the negative electrode of the first power supply;

[0029] The coil of the second low-voltage relay is connected in series between the IO controller and the positive electrode of the first power supply;

[0030] The shunt release, a normally closed contact of the first low-voltage relay, and a normally open contact of the second low-voltage relay are sequentially connected in series between the positive and negative electrodes of the second power supply.

[0031] From the above description, it can be seen that the beneficial effects of the present invention are: providing a shunt tripping protection circuit, by designing the shunt tripper into the hardware loop, connecting the shunt tripper in series with the normally closed contact of the first low-voltage relay and the normally open contact of the second low-voltage relay, and adding a normally open contact of the third low-voltage relay in parallel, and combining with the emergency stop switch to realize hardware control of the on and off of the first low-voltage relay coil, and the cooperation of the EMS system and the IO controller to realize software control of the on and off of the third low-voltage relay coil, thereby realizing hard and soft dual protection to realize timely tripping of the shunt tripper under energy storage system failure to avoid further danger.

[0032] Further, the emergency stop button includes a first emergency stop normally closed contact and a second emergency stop normally closed contact;

[0033] The first emergency stop normally closed contact and the coil of the first low-voltage relay are connected in series between the positive and negative electrodes of the first power supply, and the second emergency stop normally closed contact is connected in series between the IO controller and the negative electrode of the first power supply;

[0034] The coil of the second low-voltage relay and the coil of the third low-voltage relay are respectively connected in series between the IO controller and the positive electrode of the first power supply.

[0035] Further, the IO controller includes an IO input pin and an IO output pin;

[0036] The IO input pin and the IO output pin are respectively a digital quantity input port and a digital quantity output port, and the IO input pin is turned on at a low level;

[0037] The second emergency stop normally closed contact is connected in series between one of the IO input pins of the IO controller and the negative electrode of the first power supply;

[0038] The coil of the second low-voltage relay is connected in series between one of the IO output pins of the IO controller and the positive electrode of the first power supply;

[0039] The coil of the third low-voltage relay is connected in series between another IO output pin of the IO controller and the positive electrode of the first power supply.

[0040] From the above description, it can be seen that an IO controller with digital input and output and low-level conduction is designed to ensure that the EMS system can timely judge the system status according to the level changes of each IO input pin and IO output pin of the IO controller, and timely control the level changes of each IO input pin and IO output pin of the IO controller in time when the energy storage system fails to control the tripping of the shunt release in time, so as to achieve safety protection of the system.

[0041] Furthermore, the output voltage of the first power supply is lower than the output voltage of the second power supply.

[0042] From the above description, it can be seen that the first power supply is used to power the IO controller and other single-chip microcomputers, and the second power supply is used to provide voltage for the operation of the shunt release. In order to ensure that the shunt release can work normally and fall off to disconnect the system main incoming line switch when a system failure occurs, the power supply voltage for the shunt release needs to be greater than the power supply voltage for the single-chip microcomputer.

[0043] Furthermore, the first power supply is a 24V power supply, and the second power supply is a 220V power supply.

[0044] It can be seen from the above description that the first power supply adopts 24V power supply and the second power supply adopts 220V voltage, which meets the normal working voltage requirements of the IO controller and the shunt release.

[0045] Furthermore, the IO input pin and the IO output pin of the IO controller are respectively a digital quantity input port and a digital quantity output port, and the IO input pin is turned on at a low level.

[0046] Please refer to Figure 2 A shunt tripping control method adopts the above-mentioned shunt tripping protection circuit, and the EMS system performs the control steps:

[0047] S1, determine whether the energy storage system fails, if so, proceed to step S2;

[0048] S2. Detect the level state of the IO input pin connected to the second emergency stop normally closed contact of the emergency stop button in the IO controller. If the level state is the first level, it is determined that the emergency stop button is pressed, the coil of the first low-voltage relay is de-energized to restore the normally closed contact of the first low-voltage relay to the normally closed state and cooperate with the closed normally open contact in the second low-voltage relay to energize and trip the shunt release, and disconnect the system main incoming line switch. At this time, the IO output pin connected to the coil of the third low-voltage relay in the IO controller is controlled to output the first level, so that both ends of the coil of the third low-voltage relay are energized, the normally open contact of the third low-voltage relay is closed, and the shunt release is kept energized and tripped.

[0049] From the above description, it can be seen that the beneficial effects of the present invention are: based on the same technical concept, using the above-mentioned shunt tripping protection circuit, a shunt tripping control method is provided, by designing the shunt tripper into the hardware loop, connecting the shunt tripper in series with the normally closed contact of the first low-voltage relay and the normally open contact of the second low-voltage relay, and adding a normally open contact of the third low-voltage relay in parallel, and combining with the emergency stop switch to realize hardware control of the on and off of the first low-voltage relay coil, and the cooperation of the EMS system and the IO controller to realize software control of the on and off of the third low-voltage relay coil, thereby realizing hard and soft dual protection to realize timely tripping of the shunt tripper under energy storage system failure to avoid further danger.

[0050] Furthermore, the step S2 also includes:

[0051] When it is detected that the level state of the IO input pin connected to the second emergency stop normally closed contact in the IO controller is the second level, it is determined that the emergency stop button is not pressed. At this time, the IO input pin connected to the second emergency stop normally closed contact in the IO controller is directly controlled to input the first level, and the IO output pin connected to the coil of the third low-voltage relay in the IO controller is controlled to output the first level, so that both ends of the coil of the third low-voltage relay are energized, the normally open contacts of the third low-voltage relay are closed, the shunt release is turned on under the power supply of the second power supply, the shunt release is energized and tripped, and the system main incoming line switch is disconnected.

[0052] From the above description, it can be seen that when it is detected that the emergency stop button is not pressed, that is, the hardware cannot achieve timely power off due to system failure, the shunt release can be directly controlled by software control to trip in time, thereby further realizing safety protection of the system.

[0053] Furthermore, the first level is a low level, and the second level is a high level.

[0054] From the above description, it can be seen that an IO controller with digital input and output and low-level conduction is designed to ensure that the EMS system can timely judge the system status according to the level changes of each IO input pin and IO output pin of the IO controller, and timely control the level changes of each IO input pin and IO output pin of the IO controller in time when the energy storage system fails to control the tripping of the shunt release in time, so as to achieve safety protection of the system.

[0055] Furthermore, the step S1 also includes:

[0056] When it is determined that the energy storage system is in a normal working state without any fault, the first power supply and the second power supply are supplying power normally, both ends of the coil of the first low-voltage relay are energized, and the normally closed contact of the first low-voltage relay changes from normally closed to open, and the process proceeds to step S3;

[0057] S3. Control the IO output pin in the IO controller connected to the coil of the second low-voltage relay to output the first electrical level after a first delay, so that both ends of the coil of the second low-voltage relay are energized, the normally open contacts of the second low-voltage relay are closed, the normally closed contacts of the first low-voltage relay remain in an open state, the shunt release does not work, and the normally open contacts of the third low-voltage relay also remain in a normally open state.

[0058] Furthermore, the first time is 50-1000 ms.

[0059] From the above description, it can be seen that since the closing time of a general low-voltage relay is between 20 and 40 ms, when the normally closed contact of the first low-voltage relay changes from closed to open and then closes the normally open contact of the second low-voltage relay, a certain amount of time needs to be reserved to ensure that the state change of the normally closed contact of the first low-voltage relay is completed, that is, the first time can be set between 50 and 1000 ms, which is greater than 20 to 40 ms, to ensure reliable operation of the circuit.

[0060] The present invention provides a shunt tripping protection circuit and a shunt tripping control method thereof, which are mainly used in scenarios where a power failure occurs in each energy storage system and the system needs to be powered off in time to avoid further danger. The following is a specific description in conjunction with a specific embodiment:

[0061] Please refer to Figure 1 , Embodiment 1 of the present invention is:

[0062] A shunt trip protection circuit, such as Figure 1 As shown, it includes an emergency stop button, an IO controller 20, a shunt release, an EMS system 10, a first low voltage relay, a second low voltage relay and a third low voltage relay. The EMS system 10 and the IO controller 20 are connected for communication and control.

[0063] Among them, the IO controller 20 is powered by a first power supply, and the shunt release is powered by a second power supply. In this embodiment, the output voltage of the first power supply is less than the output voltage of the second power supply, that is, the first power supply is used to power the IO controller 20 and other single-chip microcomputers, and the second power supply is used to provide voltage for the operation of the shunt release. In order to ensure that the shunt release can work normally when a system failure occurs and fall off to disconnect the system main incoming line switch, the power supply voltage for the shunt release needs to be greater than the power supply voltage for the single-chip microcomputer; and in this embodiment, the first power supply adopts a 24V power supply and the second power supply adopts a 220V voltage, which meets the normal working voltage requirements of the IO controller 20 and the shunt release.

[0064] At the same time Figure 1 As shown, the emergency stop button includes a first emergency stop normally closed contact SB_1 and a second emergency stop normally closed contact SB_2, one end of the first emergency stop normally closed contact SB_1 is connected in series with the coil KA1 of the first low-voltage relay and then connected to 24V+, and the other end is connected to 24V-, and one end of the second emergency stop normally closed contact SB_2 is connected to an IO input pin DI1 of the IO controller 20, and the other end is connected to 24V-. In this embodiment, the emergency stop button is used to control the power supply of the first low-voltage relay in hardware and feed back the emergency stop signal to the IO controller 20, and then the IO controller 20 sends the fed-back emergency stop signal to the EMS system 10.

[0065] At the same time, the coil KA2 of the second low-voltage relay is connected in series between an IO output pin DO1 of the IO controller and 24V+; the shunt release MX, a normally closed contact KA1_1 of the first low-voltage relay, and a normally open contact KA2_1 of the second low-voltage relay are connected in series between 220V L and 220V N in sequence; the coil KA3 of the third low-voltage relay is connected in series between another IO output pin DO2 of the IO controller 20 and 24V+, and one end of a normally open contact KA3_1 of the third low-voltage relay is connected between the shunt release MX and the normally closed contact KA1_1 of the first low-voltage relay, and the other end is connected to 24V-. In this embodiment, the IO control 20 can control the power supply of the second low-voltage relay and the third low-voltage relay with the signal given by the EMS system 10.

[0066] That is, in this embodiment, by designing the shunt release into the hardware circuit, the shunt release MX is connected in series with the normally closed contact KA1_1 of the first low-voltage relay and the normally open contact KA2_1 of the second low-voltage relay, and a normally open contact KA3_1 of the third low-voltage relay is added in parallel, and the emergency stop switch is combined to realize hardware control of the on and off of the first low-voltage relay coil KA1, and the EMS system 10 and the IO controller 20 cooperate to realize software control of the on and off of the third low-voltage relay coil KA3, thereby realizing hard and soft dual protection to realize timely tripping of the shunt release in the event of a failure in the energy storage system to avoid further danger.

[0067] Please refer to Figure 1 , Embodiment 2 of the present invention is:

[0068] A shunt tripping protection circuit, based on the above embodiment 1, in this embodiment, as Figure 1 As shown, the IO input pin and the IO output pin of the IO controller 20 are respectively a digital quantity input port and a digital quantity output port, and the IO input pin is turned on at a low level.

[0069] That is, an IO controller 20 with digital input and output and low-level conduction is designed to ensure that the EMS system 10 can timely judge the system status according to the level changes of each IO input pin and IO output pin of the IO controller 20, and timely control the level changes of each IO input pin and IO output pin of the IO controller 20 in time when the energy storage system fails to control the tripping of the shunt release in time, thereby realizing safety protection of the system.

[0070] It is also worth noting that in the energy storage system using a shunt trip protection circuit in this embodiment, the hard control circuit is only explained by accessing the emergency stop. The hard control circuit can access more safety strategies, such as fire start, lightning strike, flooding and other signals can all be added to trigger hard control according to actual conditions to ensure equipment safety. At the same time, the 24V power supply of the IO controller 20 and the 220V power supply of the shunt tripper must be taken from the UPS back end of the energy storage system. After the main incoming line switch of the system is disconnected, the other control modules of the system are still in normal working state.

[0071] Please refer to Figure 2 , Embodiment 3 of the present invention is:

[0072] A shunt tripping control method, using a shunt tripping protection circuit in the above-mentioned embodiment 1 or embodiment 2, such as Figure 2 As shown, the EMS system 10 performs the control steps:

[0073] S1. Determine whether the energy storage system fails. If so, proceed to step S2.

[0074] S2. The EMS system 10 detects the level state of the IO input pin DI1 connected to the second emergency stop normally closed contact SB_2 of the emergency stop button in the IO controller 20. If the level state is the first level, it is determined that the emergency stop button is pressed. At this time, the first emergency stop normally closed contact SB_1 and the second emergency stop normally closed contact SB_2 of the emergency stop button are both changed from normally closed to open, and the coil KA1 of the first low-voltage relay is de-energized to make the normally closed contact KA1_1 of the first low-voltage relay restore to the normally closed state, and together with the normally open contact KA2_1 of the second low-voltage relay which is in a closed state at this time, the shunt release MX is turned on under the power supply of the second power supply 220V, the shunt release is energized and tripped, and the system main incoming line switch is disconnected.

[0075] At this time, the IO output pin DO2 connected to the coil KA3 of the third low-voltage relay in the control IO control 20 outputs the first level, so that the coil KA3 of the third low-voltage relay is energized, and the normally open contact KA3_1 of the third low-voltage relay is closed, maintaining the energized tripping state of the shunt release MX.

[0076] That is, in this embodiment, based on the same technical concept, a shunt tripping control method is provided for a shunt tripping protection circuit of the above-mentioned embodiment one or embodiment two, by designing the shunt tripper into the hardware loop, connecting the shunt tripper MX in series with the normally closed contact KA1_1 of the first low-voltage relay and the normally open contact KA2_1 of the second low-voltage relay, and adding a normally open contact KA3_1 of the third low-voltage relay in parallel, and combining with the emergency stop switch to realize hardware control of the on and off of the first low-voltage relay coil KA1, and the cooperation of the EMS system 10 and the IO controller 20 to realize software control of the on and off of the third low-voltage relay coil KA3, thereby realizing hard and soft dual protection to realize timely tripping of the shunt tripper under energy storage system failure to avoid further danger.

[0077] Embodiment 4 of the present invention is:

[0078] A shunt tripping control method, based on the above-mentioned embodiment 3, in this embodiment, step S2 further includes:

[0079] When the EMS system 10 detects that the level state of the IO input pin DI1 connected to the second emergency stop normally closed contact SB_2 in the IO controller 20 is the second level, it is determined that the emergency stop button fault has not been pressed. At this time, the EMS system 10 directly controls the IO input pin DI1 connected to the second emergency stop normally closed contact SB_2 in the IO controller 20 to input the first level, and controls the IO output pin DO2 connected to the coil KA3 of the third low-voltage relay in the IO controller 20 to output the first level, so that both ends of the coil KA3 of the third low-voltage relay are energized, the normally open contact KA3_1 of the third low-voltage relay is closed, and the shunt release MX is turned on under the power supply of the second power supply 220V, and the shunt release starts to trip, disconnecting the system main incoming line switch.

[0080] That is, when it is detected that the emergency stop button is not pressed, that is, the hardware cannot achieve timely power off due to system failure, the shunt release can be directly controlled to trip in time through software control, thereby further realizing safety protection of the system.

[0081] That is, there are two situations in which the shunt release works: one is that the normally closed contact KA1_1 of the first low-voltage relay and the normally open contact KA2_1 of the second low-voltage relay are in a closed state; the other is that the normally open contact KA3_1 of the third low-voltage relay is in a closed state. Both of these can make the shunt release MX powered by 220V and the shunt release trips.

[0082] In addition, in this embodiment, the first level is a low level, and the second level is a high level.

[0083] That is, the IO controller 20 is designed with digital input and output and low-level conduction, so as to ensure that the EMS system 10 can timely judge the system status according to the level changes of each IO input pin and IO output pin of the IO controller 20, and timely control the level changes of each IO input pin and IO output pin of the IO controller 20 in time when the energy storage system fails to control the tripping of the shunt release in time, so as to realize the safety protection of the system.

[0084] At the same time, this embodiment also provides a control strategy for the EMS system 10 under normal operation of the energy storage system, that is, step S1 also includes:

[0085] When it is determined that the energy storage system is in normal working state without any fault, that is, the first power supply 24V and the second power supply 220V are supplying power normally, both ends of the coil KA1 of the first low-voltage relay are energized, and the normally closed contact KA1_1 of the first low-voltage relay changes from normally closed to open, and then the process goes to step S3:

[0086] S3. The EMS system 10 controls the IO output pin DO1 connected to the coil KA2 of the second low-voltage relay in the IO controller 20 to output the first level after a first delay, so that both ends of the coil KA2 of the second low-voltage relay are energized, the normally open contact KA2_1 of the second low-voltage relay is closed, the normally closed contact KA1_1 of the first low-voltage relay remains in the open state, the shunt release does not work, and the normally open contact KA3_1 of the third low-voltage relay also remains in the normally open state.

[0087] Meanwhile, in this embodiment, the first time is 50-1000 ms.

[0088] That is, a delay mechanism is added to the hardware control loop, that is, the shunt release control loop is connected in series with the normally open contact KA2_1 of the second low-voltage relay, and the system remains in a disconnected state within the first time of power-on to prevent the shunt release MX from being energized and immediately tripping at the moment of power-on, causing the system to be unable to operate. In addition, since the closing time of a general low-voltage relay is between 20 and 40 ms, when the normally closed contact KA1_1 of the first low-voltage relay changes from closed to open and then closes the normally open contact KA2_1 of the second low-voltage relay, a certain amount of time needs to be reserved to ensure that the state change of the normally closed contact KA1_1 of the first low-voltage relay is completed, that is, the first time can be set between 50 and 1000 ms, which is greater than 20 to 40 ms, to ensure reliable operation of the circuit.

[0089] In summary, the shunt tripping protection circuit and shunt tripping control method provided by the present invention have the following beneficial effects:

[0090] 1. Add hardware control on the basis of software control to ensure the normal operation of the system and increase the timeliness of protection;

[0091] 2. Add a delay mechanism to the hardware control circuit, that is, connect the normally open contact KA2_1 of the second low-voltage relay in series with the shunt release control circuit, and keep the system disconnected within the first time after power-on to prevent the shunt release MX from tripping immediately after power-on, causing the system to fail to operate;

[0092] 3. Combine hard control with soft control to improve the compatibility of protection circuits in case of faults.

[0093] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A shunt tripping protection circuit, characterized in that: It includes an emergency stop button, an IO controller, a shunt release, a first low-voltage relay, a second low-voltage relay, a third low-voltage relay, and an EMS system that communicates and controls with the IO controller; The IO controller is powered by a first power supply, and the shunt release is powered by a second power supply; The emergency stop button is connected to the first low-voltage relay and the IO controller, controls the power supply of the first low-voltage relay and feeds back an emergency stop signal to the IO controller; The IO controller connects and controls the power supply of the second low-voltage relay and the third low-voltage relay; The shunt release, a normally closed contact of the first low-voltage relay, and a normally open contact of the second low-voltage relay are sequentially connected in series between the positive and negative electrodes of the second power supply; One end of a normally open contact of the third low-voltage relay is connected between the shunt release and the normally closed contact of the first low-voltage relay, and the other end is connected to the negative electrode of the second power supply; The emergency stop button includes a first emergency stop normally closed contact and a second emergency stop normally closed contact; The first emergency stop normally closed contact and the coil of the first low-voltage relay are connected in series between the positive and negative electrodes of the first power supply, and the second emergency stop normally closed contact is connected in series between the IO controller and the negative electrode of the first power supply; The coil of the second low-voltage relay and the coil of the third low-voltage relay are respectively connected in series between the IO controller and the positive electrode of the first power supply; The IO controller includes an IO input pin and an IO output pin; The IO input pin and the IO output pin are respectively a digital quantity input port and a digital quantity output port, and the IO input pin is turned on at a low level; The second emergency stop normally closed contact is connected in series between one of the IO input pins of the IO controller and the negative electrode of the first power supply; The coil of the second low-voltage relay is connected in series between one of the IO output pins of the IO controller and the positive electrode of the first power supply; The coil of the third low-voltage relay is connected in series between another IO output pin of the IO controller and the positive electrode of the first power supply; After determining that the energy storage system has failed, the EMS system detects the level state of the IO input pin connected to the second emergency stop normally closed contact of the emergency stop button in the IO controller. If the level state is the first level, it is determined that the emergency stop button is pressed, the coil of the first low-voltage relay is de-energized so that the normally closed contact of the first low-voltage relay is restored to normally closed and cooperates with the closed normally open contact in the second low-voltage relay to energize and trip the shunt release, disconnecting the system main incoming line switch. At this time, the IO output pin connected to the coil of the third low-voltage relay in the IO controller is controlled to output the first level, so that both ends of the coil of the third low-voltage relay are energized, the normally open contact of the third low-voltage relay is closed, and the shunt release is kept energized and tripped.

2. A shunt tripping protection circuit according to claim 1, characterized in that: An output voltage of the first power supply is lower than an output voltage of the second power supply.

3. A shunt tripping protection circuit according to claim 2, characterized in that: The first power supply is a 24V power supply, and the second power supply is a 220V power supply.

4. A shunt tripping control method, using a shunt tripping protection circuit as claimed in any one of claims 1 to 3, characterized in that: EMS system performs control steps: S1, determine whether the energy storage system fails, if so, proceed to step S2; S2. Detect the level state of the IO input pin connected to the second emergency stop normally closed contact of the emergency stop button in the IO controller. If the level state is the first level, it is determined that the emergency stop button is pressed, the coil of the first low-voltage relay is de-energized to restore the normally closed contact of the first low-voltage relay to the normally closed state and cooperate with the closed normally open contact in the second low-voltage relay to energize and trip the shunt release, and disconnect the system main incoming line switch. At this time, the IO output pin connected to the coil of the third low-voltage relay in the IO controller is controlled to output the first level, so that both ends of the coil of the third low-voltage relay are energized, the normally open contact of the third low-voltage relay is closed, and the shunt release is kept energized and tripped.

5. A shunt tripping control method according to claim 4, characterized in that: The step S2 also includes: When it is detected that the level state of the IO input pin connected to the second emergency stop normally closed contact in the IO controller is the second level, it is determined that the emergency stop button is not pressed. At this time, the IO input pin connected to the second emergency stop normally closed contact in the IO controller is directly controlled to input the first level, and the IO output pin connected to the coil of the third low-voltage relay in the IO controller is controlled to output the first level, so that both ends of the coil of the third low-voltage relay are energized, the normally open contacts of the third low-voltage relay are closed, the shunt release is turned on under the power supply of the second power supply, the shunt release is energized and tripped, and the system main incoming line switch is disconnected.

6. A shunt tripping control method according to claim 5, characterized in that: The first level is a low level, and the second level is a high level.

7. A shunt tripping control method according to claim 6, characterized in that: The step S1 also includes: When it is determined that the energy storage system is in a normal working state without any fault, the first power supply and the second power supply are supplying power normally, both ends of the coil of the first low-voltage relay are energized, and the normally closed contact of the first low-voltage relay changes from normally closed to open, and the process proceeds to step S3; S3. Control the IO output pin in the IO controller connected to the coil of the second low-voltage relay to output the first electrical level after a first delay, so that both ends of the coil of the second low-voltage relay are energized, the normally open contacts of the second low-voltage relay are closed, the normally closed contacts of the first low-voltage relay remain in an open state, the shunt release does not work, and the normally open contacts of the third low-voltage relay also remain in a normally open state.

8. A shunt tripping control method according to claim 7, characterized in that: The first time is 50~1000ms.

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