All-vanadium redox flow battery SOC balance monitoring and control system

Abstract

The invention belongs to the field of all-vanadium redox flow battery systems, and discloses an all-vanadium redox flow battery SOC balance monitoring and control system. Comprising a system architecture part, a control loop part and a grid architecture part. Equipment interlocking is adopted in control hardware, and short circuit is avoided; logic interlocking is adopted on control software, so that maloperation is avoided; dual-network-segment Ethernet monitoring is adopted for data communication, so that interference and data optimization processing are avoided; automatic balanced work and stop can be realized in the aspects of control strategies and control modes, three control modes, namely a charge-discharge mode, a charge-only mode and a discharge-only mode, can be realized according to an SOC set value, and the control modes are diversified and higher in adaptability; a human-computer interface and principle unification are clearer and more visual.

Description

Technical Field

[0001] The invention belongs to the field of all-vanadium liquid flow battery systems, and in particular relates to an all-vanadium liquid flow battery SOC balancing monitoring and control system. Background Art

[0002] As the world economy recovers with difficulty, traditional energy is increasingly scarce, and the earth's environment is deteriorating, a wave of new energy industry revolution that has a profound impact on human society is sweeping the world! The inherent randomness, volatility, intermittency, peak-shaving difficulties, and grid-connection difficulties of new energy determine that its large-scale development must be supported by advanced energy storage technology.

[0003] All-vanadium liquid flow batteries use vanadium electrolytes of different valence states to circulate through electrodes from bottom to top to perform electrochemical reactions, thereby achieving the mutual conversion of chemical energy and electrical energy. All-vanadium liquid flow batteries are the world's largest, most technologically advanced, and most industrialized high-efficiency rechargeable fuel cells. They have the advantages of high power, high energy, high efficiency, low cost, long life, and no pollution. They have good application prospects in photovoltaic power generation, wind power generation, distributed power stations, power grid peak regulation, communication base stations, UPS / EPS power supplies, transportation and municipal administration, military power storage, and other broad fields, and are about to bring unprecedented and far-reaching new energy industry revolutions to mankind.

[0004] With the rapid development of all-vanadium liquid flow batteries in the long-term energy storage industry, it is crucial to maintain a stable balance between the SOC values ​​of different battery modules in the battery cells of multi-series battery modules so that all SOC values ​​of the multi-series battery modules can be fully charged or discharged synchronously. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides an all-vanadium liquid flow battery SOC balancing monitoring and control system, which can be adapted to a battery unit composed of multiple battery modules. Equipment interlocking is adopted in the control hardware to avoid short circuit; logic interlocking is adopted in the control software to avoid malfunction; dual-segment Ethernet monitoring is adopted in data communication to avoid interference and data optimization processing; automatic balancing work and stop can be realized in the control strategy and control method, and three control modes can be realized according to the SOC setting value, namely, charge and discharge mode, charge-only mode, and discharge-only mode. The control modes are diverse and more adaptable; the human-machine interface and principle are unified to be clearer and more intuitive.

[0006] The above object of the present invention is achieved through the following technical solutions: A vanadium liquid flow battery SOC equalization monitoring and control system, including an equalizer control cabinet, which has three parts, namely, a system architecture part, a control loop part, and a network architecture part. The specific structure is as follows:

[0007] System architecture: including DC contactors and DC fuses. The DC contactors are divided into main DC contactors and branch DC contactors. The SOC equalizer outside the equalizer control cabinet is connected to the main DC contactor inside the equalizer control cabinet through a cable. The main DC contactor is connected to one end of the branch DC contactor by a cable. The other end of the branch DC contactor is connected to the DC fuse. The DC fuse is connected to the external all-vanadium liquid flow battery module.

[0008] Control circuit part: including circuit breaker and power supply. The low-voltage power distribution outside the equalizer control cabinet is connected to circuit breaker b, circuit breaker c and power supply in sequence through cables. A cable is provided on the front cable of circuit breaker b to connect one end of circuit breaker a, and the other end of circuit breaker a is grounded through the cable. The power supply is also connected to one end of the DC circuit breaker through the cable, and the other end of the DC circuit breaker is connected to the external contactor control circuit power supply. The power supply is also connected to one end of the fuse terminal connected in parallel with the DC circuit breaker through the cable, and the other end of the fuse terminal is connected to the electrical equipment outside the equalizer control cabinet.

[0009] Grid architecture part: includes Ethernet communication module, CPU controller, digital input module, touch screen, switch. The CPU controller is connected to the SOC equalizer and battery unit outside the equalizer control cabinet through the switch. The touch screen is connected to the external switch outside the equalizer control cabinet through the switch. The Ethernet communication module is connected to the external switch outside the equalizer control cabinet. The CPU controller is provided with a serial communication module, and the serial communication module is connected to the SOC control module outside the equalizer control cabinet.

[0010] Furthermore, the equalizer control cabinet is provided with a ventilation filter and an emergency stop button on the front door, a fan filter on the rear door, a lighting lamp on the top of the side, and a heater on the inner side.

[0011] Furthermore, the number of the main DC contactors is one or two, the number of the branch DC contactors is 2-12, and the number of the DC fuses is the same as that of the branch DC contactors.

[0012] Furthermore, the circuit breakers b and c are connected by cables to circuit breakers d, e and f in parallel, circuit breaker d is further connected to a socket, circuit breaker e is further connected to a lighting lamp through a door-controlled switch and to a cooling fan through a temperature-controlled switch a, and circuit breaker f is further connected to a heater through a temperature-controlled switch b.

[0013] Furthermore, the heat dissipation fans are provided in plurality, the heaters are provided in plurality, and the corresponding temperature control switches b are provided in a plurality equal to the number of the heaters.

[0014] Furthermore, the fuse terminals are provided with a plurality of fuse terminals connected in parallel, which are respectively connected to different electrical equipment outside the equalizer control cabinet.

[0015] Furthermore, a lightning surge protector is provided on the cable grounding wire of the circuit breaker a.

[0016] Furthermore, the DC circuit breaker is provided with a plurality of parallel connections, which are respectively connected to different contactor control circuit power supplies outside the equalizer control cabinet.

[0017] Furthermore, the battery unit is provided in plurality, and the switch is connected to the plurality of battery units respectively.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: the SOC balancing monitoring and control system of the all-vanadium liquid flow battery of the present invention can adapt to battery cells composed of multiple battery modules, and can adapt to battery cells of up to two six-string battery modules, that is, it can simultaneously determine the SOC values ​​of up to twelve groups of batteries and then determine which group of battery modules needs to be balanced. The control hardware adopts device interlocking to avoid short circuits; the control software adopts logic interlocking to avoid malfunctions; the data communication adopts dual-segment Ethernet monitoring to avoid interference and data optimization processing; the control strategy and control method can realize automatic balancing and stopping, and three control modes can be realized according to the SOC setting value, namely, charging and discharging mode, charging-only mode, and discharging-only mode, and the control mode is more diverse and more adaptable; the human-machine interface and principle are unified and clearer and more intuitive. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0020] Figure 1 It is a schematic diagram of the partial structure of the system architecture of the all-vanadium liquid flow battery SOC equalization monitoring and control system of the present invention;

[0021] Figure 2 It is a schematic diagram of the control loop of the SOC equalization monitoring and control system of the all-vanadium liquid flow battery of the present invention;

[0022] Figure 3 This is a schematic diagram of the network architecture of the SOC balancing monitoring and control system of the all-vanadium liquid flow battery of the present invention;

[0023] Figure 4 It is a schematic diagram of the cabinet layout structure of the equalizer control cabinet of the all-vanadium liquid flow battery SOC equalization monitoring and control system of the present invention.

[0024] In the figure, 1. Main DC contactor; 2. Sub-DC contactor; 3. DC fuse; 4. All-vanadium liquid flow battery module; 5. SOC equalizer; 6. Energy storage converter; 7. Circuit breaker a; 8. Circuit breaker b; 9. Circuit breaker c; 10. Circuit breaker d; 11. Circuit breaker e; 12. Circuit breaker f; 13. Power supply; 14. DC circuit breaker; 15. Socket; 16. Door switch; 17. Temperature control switch a; 18. Cooling fan; 19. Lighting; 20. Temperature control switch b; 21. Heater; 22. Low voltage power distribution; 23. Insurance terminal; 24. Lightning surge protector; 25. Ethernet communication module; 26. CPU controller; 27. Serial communication module; 28. Touch screen; 29. ​​Switch; 30. Battery unit; 31. External switch; 32. Digital input module; 33. Emergency stop button; 34. Fan filter; 35. Lighting; 36. Ventilation filter; 37. SOC control module. DETAILED DESCRIPTION

[0025] The present invention is described in detail below by specific examples, but the protection scope of the present invention is not limited. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.

[0026] Example 1

[0027] An all-vanadium liquid flow battery SOC balancing monitoring and control system includes a balancer control cabinet. The balancer control cabinet has three parts, namely, a system architecture part, a control loop part, and a network architecture part. The specific structure is as follows:

[0028] System architecture: including DC contactors and DC fuses. The DC contactors are divided into a main DC contactor 1 and a branch DC contactor 2. The SOC equalizer 5 outside the equalizer control cabinet is connected to the main DC contactor 1 inside the equalizer control cabinet through a cable. The main DC contactor 1 is connected to one end of the branch DC contactor 2 by a cable. The other end of the branch DC contactor 2 is connected to a DC fuse 3. The DC fuse 3 is connected to an external all-vanadium liquid flow battery module 4.

[0029] Control circuit part: including circuit breaker, power supply 13, low voltage power distribution 22 outside the equalizer control cabinet is connected to circuit breaker b8, circuit breaker c9, power supply 13 in sequence through cables, and a cable is provided on the front cable of circuit breaker b8 to connect one end of circuit breaker a7, and the other end of circuit breaker a7 is grounded through the cable; power supply 13 is also connected to one end of DC circuit breaker 14 through a cable, and the other end of DC circuit breaker 14 is connected to the external contactor control circuit power supply through a cable, and power supply 13 is also connected to one end of fuse terminal 23 connected in parallel with DC circuit breaker 14 through a cable, and the other end of fuse terminal 23 is connected to the electrical equipment outside the equalizer control cabinet;

[0030] Grid architecture part: includes Ethernet communication module 25, CPU controller 26, digital input module 32, touch screen 28, switch 29. The CPU controller 26 is connected to the SOC equalizer 5 and battery unit 30 outside the equalizer control cabinet through the switch 29. The touch screen 28 is connected to the external switch 31 outside the equalizer control cabinet through the switch 29. The Ethernet communication module 25 is connected to the external switch 31 outside the equalizer control cabinet. The CPU controller 26 is provided with a serial communication module 27, and the serial communication module 27 is connected to the SOC control module 37 outside the equalizer control cabinet.

[0031] The front door of the equalizer control cabinet is provided with a ventilation filter 36 and an emergency stop button 33, the rear door is provided with a fan filter 34, the top of the side is provided with a lighting lamp 35, and the inner side is also provided with a heater; the total DC contactor 1 is provided with two, and the sub-DC contactors 2 are provided with 12, each total DC contactor 1 is connected to 6 sub-DC contactors 2, and the number of DC fuses 3 is the same as that of the sub-DC contactors 2; the circuit breakers B8 and C9 are also connected by cables to parallel circuit breakers D10, E11, and F12, and the circuit breaker D10 is also connected to a socket 15, and the circuit breaker E11 is also connected to a lighting lamp 19 through a door-controlled switch 16 and to a temperature control switch A17. There is a cooling fan 18, and the circuit breaker f12 is connected to a heater 21 through a temperature control switch b20; the cooling fans 18 are provided with two, the heaters 21 are provided with two, and the corresponding temperature control switches b20 are provided with a plurality of the same number as the heaters 21; the fuse terminals 23 are provided with 12 in parallel, which are not shown in the figure and are respectively connected to different electrical equipment outside the equalizer control cabinet; the circuit breaker a7 cable grounding wire is provided with a lightning surge protector 24; the DC circuit breaker 14 is provided with two in parallel, which are respectively connected to different contactor control circuit power supplies outside the equalizer control cabinet; the battery units 30 are provided with four, and the switch 29 is connected to the four battery units 30 respectively.

[0032] System architecture Figure 1As shown, the balancing system can adapt to the battery units of two 6-string battery modules; the DC circuit system architecture adopts a DC contactor with a DC fuse to connect to the battery module; the DC contactor main contacts adopt non-polarity requirements, which are more widely applicable and can ignore the current and wiring direction issues to achieve charging or discharging requirements, and the DC contactor can be disconnected under load. In an emergency, it can be stopped and disconnected without damaging the equipment. The working and insulation voltage level of the DC contactor is the highest to meet DC1500V. The #1 group of DC contactors 1KM and the #2 group of DC contactors 2KM are hardware interlocked, and the DC contactors in each group are interlocked with each other to ensure that there will be no short circuit and malfunction during the balancing operation; the DC fuse adopts a knife-type fast fuse, which can quickly respond to the disconnection in the event of overcurrent or short circuit accidents, and is easy to replace for maintenance and repair. The DC fuse is equipped with auxiliary contacts and the auxiliary contact status is collected to the control system. When the DC fuse core is damaged, its auxiliary contact action control system simultaneously detects its fault state and makes corresponding instructions according to the fault state.

[0033] Control loop such as Figure 2 As shown, the micro-breaker of the control circuit power supply adopts a wide voltage range model device to meet the highest 400VAC, and the control circuit is equipped with surge protection to prevent fluctuations and influences caused by overvoltage and overcurrent of the power supply voltage; the DC24V power supply is equipped with output insurance isolation function, and is equipped with maintenance, lighting, ventilation, insulation and other equipment to ensure the operating environment requirements of the control system to the greatest extent.

[0034] Network architecture such as Figure 3 As shown, the controller of the network architecture of the balancer system is equipped with dual network segments to ensure data redundancy transmission to the host computer; redundant communication is used to communicate with the balancer to ensure more stable monitoring of the balancer body, one of which is the ModBus-RTU communication protocol, the interface is RS485, and the other is the ModBus-TCP communication protocol, the interface is RJ45; all ModBus-TCP communication cables use Category 6 shielded network cables to increase anti-interference capabilities. The balancing system is equipped with a human-machine interface touch screen to realize human-machine interface operation control, data and status monitoring, etc.; the balancing system and the battery unit are equipped with hardware dry contact safety interlocks. When the battery system fails or stops in an emergency, the hardware interlock of the balancing system will be disconnected, thereby triggering the shutdown of the balancing system to avoid false operation; the balancing system and the balancer are equipped with hardware safety interlocks. When the balancing system is shut down or fails, the safety interlock of the balancer will be disconnected. When the balancer loses the hardware dry contact interlock, it will be forced to stop.

[0035] Cabinet layout Figure 4 As shown, the cabinet layout and structural standards are as follows: Material: cold-rolled steel plate, cabinet thickness 2.0, door thickness 2.0, mounting plate is aluminum-zinc plate, t=2, fixed with M8 standard screws, grade 8.8; protection grade IP65, cabinet color RAL9003 small orange grain 60~120um;

[0036] Door lock MS748-3, with 4mm lock tongue; M6*20 grounding nails are welded on the box body and door; the zero row and ground row wiring bolts in the box are both M5, and the wire binding bracket needs to be welded on the inside of the door; the hinge is installed on the inside and fixed with 2 screws, model is Shengjiu CL201-3, and the hinge hole in the box needs to be padded with waterproof gaskets and glued; the base is 150㎜ high and made of 4MM steel plate, and the base forklift baffle uses 304 stainless steel M6 hexagon socket countersunk bolts; each box door is equipped with a Shengjiu door stopper TX92 -2 (can support the door at the maximum opening angle), installed at the bottom, the door opening angle is 110 degrees; sealed with PU foam strips; unmarked size tolerances are in accordance with GB / T1804-2000C grade requirements; the guide rails in the cabinet must be flush with the wire trough according to the width of the cabinet; the distribution box ensures grounding continuity; the exposed bolts are made of 304 stainless steel; equipped with fluorescent lamps and limiters; door-on-door structure, tempered glass windows are installed on the small door, and wire bundle brackets are installed on the door; wire cover specifications: opening Menstruation 40 pcs; External doors are equipped with machined steel.

[0037] The working mode and process of the balancing system are as follows:

[0038] 6.1 Prerequisites for using the balancing system:

[0039] ① The communication between the balancing control cabinet and the two battery units is normal

[0040] ② The operating status and SOC data of the corresponding battery read by communication are normal

[0041] ③ The communication between the balance control cabinet and the equalizer is normal (the read balancer status and data display are normal)

[0042] ④ The balanced control cabinet has no communication faults and all contactor fuses have no faults.

[0043] ⑤ The equalizer body has no faults and is in normal shutdown or running state

[0044] ⑥ At least one battery unit is in normal operation

[0045] 6.2 Main strategies of the balanced system:

[0046] Take the difference between the maximum and minimum SOC values ​​of the two sets of battery cells respectively, and perform balanced adjustment on the battery module with the largest difference;

[0047] ① When the balancing system is in charge and discharge mode: the battery module with the largest difference between the SOC and the average value in the selected battery cell is balanced

[0048] ② When the balancing system is in discharge-only mode: balance the battery module with the maximum SOC in the selected battery cell

[0049] ③ When the balancing system is in charge-only mode: balance the battery module with the minimum SOC in the selected battery cell

[0050] 6.3 Manual control of the balancing system:

[0051] ① Manual start process: Confirm that the battery unit is in operation state—》The contactor of the corresponding SOC of the control cabinet is turned to manual—》Click the main contactor of the corresponding contactor group of the corresponding battery unit to close—》Click the corresponding SOC slave contactor to close—》The red lights of both closing are on—》The convergence closing state of the corresponding group arrives—》[Convergence closing completed]—》The balancer clicks the AC mode setting (Note: The constant voltage mode of the control cabinet is only used for experiments and should not be selected)—》The AC power mode state arrives—》The balancer manual power setting (for example, charging: -25KW)—》The AC power setting feedback arrives and the display is the same as the set value—》The balancer control clicks to start (Note: When the control cabinet stops abnormally, you need to click the fault reset button first)—》The balancer operation state arrives—》At this time, the balancer startup sound can be heard and the DC side voltage, current and power have values ​​and are displayed normally—》[Balancing system starts successfully]

[0052] ② Manual stop process: The manual power setting of the control cabinet is set to 0KW—》The real-time power feedback display is also 0KW—》Click the balancer stop button—》The balancer stop state arrives—》[Balancer stop successful]—》Click the main contactor of the corresponding contactor group of the corresponding battery unit to open—》Click the corresponding SOC slave contactor to open—》The green lights of both openings are on—》The convergence closing state of the corresponding group disappears—》[Opening completed]—》[Balancer system stopped successfully]

[0053] 6.4 Automatic control of balancing system:

[0054] ① Automatic start and stop process: Make sure all contactors in the control cabinet are in the open state—》Make sure the balancer is in the normal shutdown state—》Make sure the balancer is in AC power mode—》Set the start value of the balance system (default 2%)—》Set the stop value of the balance system (default 1%)—》Set the inspection time of the balance system (default 36min)—》Set the interval time of the balance system (default 3min)—》Automatic state charging / discharging power setting (for example: -25KW / 25KW)—》Click the system automatic command—》The system automatic state arrives—》Click the inspection timing start—》The timing start state arrives—》At this time, the balance system will start according to the inspection timing time. The system automatically selects the SOC battery modules that meet the conditions in the two battery units for closing -> contactor closing is completed -> start the balancer -> the balancer running state reaches [automatic start completed] -> when the timing time is up -> stop the balancer -> disconnect the balancer interlock OK signal again -> delay the opening contactor [automatic stop completed] -> go through the interval time -> interval time is up -> continue to judge the SOC that meets the conditions for the next round of balancing start judgment [balancing system infinite loop] -> the balancing system will not be in the stop or standby state until the battery unit stops or fails or the balancing system is switched to manual state or the stop conditions of the balancer system are met.

[0055] (After the balancing system switches to automatic mode, if all systems are fault-free, unattended self-control will be implemented)

[0056] ② Exit the automatic process: During the automatic operation process—》Click the inspection timer stop—》The timer stop state comes—》Click the system manual command—》The system manual state comes—》At this time, if the system is in operation, the balancer will be stopped and the contactor will be opened. (After the balance system switches to manual state, it will be completely controlled by humans).

[0057] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A vanadium liquid flow battery SOC balancing monitoring and control system, characterized in that: Including the equalizer control cabinet, there are three parts in the equalizer control cabinet, namely the system architecture part, the control loop part, and the network architecture part. The specific structure is as follows: System architecture: including a DC contactor and a DC fuse, wherein the DC contactor is further divided into a main DC contactor (1) and a branch DC contactor (2), wherein the SOC equalizer (5) outside the equalizer control cabinet is connected to the main DC contactor (1) inside the equalizer control cabinet via a cable, the main DC contactor (1) is connected to one end of the branch DC contactor (2) by a cable, and the other end of the branch DC contactor (2) is connected to a DC fuse (3), and the DC fuse (3) is connected to an external all-vanadium liquid flow battery module (4); The control circuit part includes a circuit breaker and a power supply (13). The low-voltage power distribution (22) outside the equalizer control cabinet is connected to the circuit breaker b (8), the circuit breaker c (9), and the power supply (13) in sequence through cables. A cable is provided on the front end cable of the circuit breaker b (8) to connect one end of the circuit breaker a (7). The other end of the circuit breaker a (7) is grounded through the cable. The power supply (13) is also connected to one end of the DC circuit breaker (14) through the cable. The other end of the DC circuit breaker (14) is connected to the external contactor control circuit power supply. The power supply (13) is also connected to one end of the fuse terminal (23) connected in parallel with the DC circuit breaker (14) through the cable. The other end of the fuse terminal (23) is connected to the electrical equipment outside the equalizer control cabinet. The grid architecture part includes an Ethernet communication module (25), a CPU controller (26), a digital input module (32), a touch screen (28), and a switch (29). The CPU controller (26) is connected to the SOC equalizer (5) and the battery unit (30) outside the equalizer control cabinet through the switch (29). The touch screen (28) is connected to the external switch (31) outside the equalizer control cabinet through the switch (29). The Ethernet communication module (25) is connected to the external switch (31) outside the equalizer control cabinet. The CPU controller (26) is provided with a serial communication module (27), and the serial communication module (27) is connected to the SOC control module (37) outside the equalizer control cabinet.

2. The all-vanadium liquid flow battery SOC equalization monitoring and control system according to claim 1, characterized in that: The equalizer control cabinet has a ventilation filter (36) and an emergency stop button (33) on the front cabinet door, a fan filter (34) on the rear cabinet door, a lighting lamp (35) on the top of the side, and a heater on the inner side.

3. The all-vanadium liquid flow battery SOC equalization monitoring and control system according to claim 1, characterized in that: The number of the main DC contactor (1) is one or two, the number of the branch DC contactors (2) is 2-12, and the number of the DC fuses (3) is the same as that of the branch DC contactors (2).

4. The all-vanadium liquid flow battery SOC equalization monitoring and control system according to claim 1, characterized in that: A parallel circuit breaker d (10), a circuit breaker e (11), and a circuit breaker f (12) are also connected by cables between the circuit breaker b (8) and the circuit breaker c (9); the circuit breaker d (10) is further connected to a socket (15); the circuit breaker e (11) is further connected to a lighting lamp (19) via a door-controlled switch (16) and to a cooling fan (18) via a temperature-controlled switch a (17); and the circuit breaker f (12) is further connected to a heater (21) via a temperature-controlled switch b (20).

5. The all-vanadium liquid flow battery SOC equalization monitoring and control system according to claim 1, characterized in that: The heat dissipation fans (18) are provided in plurality, the heaters (21) are provided in plurality, and the corresponding temperature control switches b (20) are provided in a plurality equal in number to the heaters (21).

6. The all-vanadium liquid flow battery SOC equalization monitoring and control system according to claim 1, characterized in that: The fuse terminals (23) are provided with a plurality of fuse terminals (23) connected in parallel, and are respectively connected to different electrical equipment outside the equalizer control cabinet.

7. The all-vanadium liquid flow battery SOC equalization monitoring and control system according to claim 1, characterized in that: A lightning surge protector (24) is provided on the cable grounding line of the circuit breaker a (7).

8. The all-vanadium liquid flow battery SOC equalization monitoring and control system according to claim 1, characterized in that: The DC circuit breakers (14) are provided with a plurality of parallel-connected ones, which are respectively connected to different contactor control circuit power supplies outside the equalizer control cabinet.

9. The all-vanadium liquid flow battery SOC equalization monitoring and control system according to claim 1, characterized in that: The battery units (30) are provided in plurality, and the switch (29) is respectively connected to the plurality of battery units (30).

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