A vanadium redox flow battery soc equalization monitoring and control system

Abstract

The application belongs to the field of all-vanadium redox flow battery system, and discloses a kind of all-vanadium redox flow battery SOC equalization monitoring and control system.It includes system architecture part, control loop part, grid architecture part.The application adopts device interlock on control hardware, avoids short circuit;Adopt logic interlock on control software, avoid malfunction;Adopt double network segment ethernet monitoring on data communication, avoid interference and data optimization processing;Control strategy and control mode can realize automatic equalization work and stop, and according to SOC set value, three control modes can be realized, namely charge and discharge mode, only charge mode and only discharge mode, and the control mode is more versatile;Man-machine interface and principle are more clear and intuitive.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of all-vanadium redox flow battery systems, and particularly relates to an SOC balancing monitoring and control system for all-vanadium redox flow batteries. BACKGROUND

[0002] The inherent randomness, volatility, intermittency, peak-shaving difficulty and grid-connection difficulty of new energy determine that the large-scale development of new energy must be supported by advanced energy storage technology.

[0003] An all-vanadium redox flow battery realizes the mutual conversion of chemical energy and electrical energy through the circulation of vanadium electrolyte of different valence states from bottom to top through electrodes for electrochemical reaction. The all-vanadium redox flow battery has the advantages of large power, large energy, high efficiency, low cost, long service life and no pollution, and has good application prospects in the fields of photovoltaic power generation, wind power generation, distributed power stations, grid peak shaving, communication base stations, UPS / EPS power sources, traffic and municipal administration, and military power storage, and will bring an unprecedented, significant and far-reaching new energy industry revolution to mankind.

[0004] With the rapid development of all-vanadium redox flow batteries in the long-time energy storage industry, it is crucial to maintain stable balance between the SOC values of different battery modules in the battery unit of multiple series-connected battery modules, so that all the SOC values of the multiple series-connected battery modules can be simultaneously charged or emptied. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the application provides an SOC balancing monitoring and control system for all-vanadium redox flow batteries, which can adapt to a battery unit composed of multiple series-connected battery modules, adopts device interlocking on the control hardware to avoid short circuit, adopts logic interlocking on the control software to avoid misoperation, adopts double-network segment Ethernet monitoring on data communication to avoid interference and data optimization processing, and can realize automatic balancing and stopping, three control modes of chargeable and dischargeable mode, only chargeable mode and only dischargeable mode according to the SOC set value, and clear and intuitive man-machine interface and principle.

[0006] The above object of the application is achieved by the following technical scheme: an SOC balancing monitoring and control system for all-vanadium redox flow batteries, comprising an equalizer control cabinet, which has three parts, namely a system architecture part, a control loop part and a network architecture part, and has the following specific structure:

[0007] The system architecture part includes a DC contactor and a DC fuse, the DC contactor is divided into a total DC contactor and a branch DC contactor, the SOC equalizer outside the equalizer control cabinet is connected to the total DC contactor inside the equalizer control cabinet through a cable, the total DC contactor is connected to the branch DC contactor through a cable, the branch DC contactor is connected to the DC fuse, and the DC fuse is connected to the external all-vanadium redox battery module.

[0008] The control loop part includes a circuit breaker and a power supply, the low-voltage power distribution outside the equalizer control cabinet is connected to the circuit breaker b, the circuit breaker c and the power supply in sequence through cables, the circuit breaker a is connected to the circuit breaker b through a cable, the circuit breaker a is connected to the ground through a cable, the power supply is connected to the DC circuit breaker through a cable, the DC circuit breaker is connected to the external contactor control loop power supply through a cable, the power supply is connected to the fuse terminal in parallel with the DC circuit breaker through a cable, and the fuse terminal is connected to the electrical equipment outside the equalizer control cabinet.

[0009] The grid architecture part includes an Ethernet communication module, a CPU controller, a digital quantity input module, a touch screen and a switch, the CPU controller is connected to the SOC equalizer and the 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, and a serial communication module is arranged on the CPU controller and connected to the SOC control module outside the equalizer control cabinet.

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

[0011] Further, the total DC contactor is provided with one or two, the branch DC contactor is provided with 2-12, and the number of DC fuses is the same as that of the branch DC contactors.

[0012] Further, the circuit breakers d, e and f are connected in parallel between the circuit breakers b and c, the circuit breaker d is connected to a socket, the circuit breaker e is connected to a lighting lamp through a door control switch and connected to a heat dissipation fan through a temperature control switch a, and the circuit breaker f is connected to a heater through a temperature control switch b.

[0013] Further, the heat dissipation fan is provided with a plurality of heat dissipation fans, the heater is provided with a plurality of heaters, and the temperature control switch b is provided with a plurality of temperature control switches b corresponding to the number of heaters.

[0014] Further, the fuse terminal is provided with a plurality of fuse terminals connected to different electrical equipment outside the equalizer control cabinet.

[0015] Further, the lightning surge protector is arranged on the cable grounding line of the circuit breaker a.

[0016] Further, the DC circuit breaker is provided with a plurality of parallel circuits, which are respectively connected with different contactor control loop power sources outside the equalizer control cabinet.

[0017] Further, the battery unit is provided with a plurality of battery units, and the switch is connected with the plurality of battery units.

[0018] Compared with the prior art, the SOC equalization monitoring and control system of the all-vanadium redox flow battery can adapt to a battery unit composed of multiple battery modules, and can adapt to a battery unit of two six-battery-module maximum, that is, can simultaneously judge twelve groups of battery SOC values and then judge which group of battery module needs to be balanced. On the control hardware, device interlocking is adopted to avoid short circuit; on the control software, logical interlocking is adopted to avoid misoperation; on the data communication, double-network-segment Ethernet monitoring is adopted to avoid interference and data optimization processing; on the control strategy and control mode, automatic balancing work and stop can be realized, and three control modes, namely, chargeable and dischargeable mode, only chargeable mode and only dischargeable mode, can be realized according to the SOC set value, and the control mode is various and more adaptable; the man-machine interface is unified with the principle and is clearer and more intuitive. BRIEF DESCRIPTION OF DRAWINGS

[0019] The application will be further described below in combination with the drawings and specific embodiments

[0020] Figure 1 is a structural schematic diagram of the system architecture part of the SOC equalization monitoring and control system of the all-vanadium redox flow battery;

[0021] Figure 2 is a structural schematic diagram of the control loop part of the SOC equalization monitoring and control system of the all-vanadium redox flow battery;

[0022] Figure 3 is a structural schematic diagram of the network architecture part of the SOC equalization monitoring and control system of the all-vanadium redox flow battery;

[0023] Figure 4 is a structural schematic diagram of the cabinet body layout of the equalizer control cabinet of the SOC equalization monitoring and control system of the all-vanadium redox flow battery.

[0024] 1. total DC contactor; 2. partial DC contactor; 3. DC fuse; 4. all-vanadium redox 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. gate switch; 17. temperature control switch a; 18. heat dissipation fan; 19. lighting lamp; 20. temperature control switch b; 21. heater; 22. low-voltage power distribution; 23. fuse terminal; 24. lightning surge protector; 25. Ethernet communication module; 26. CPU controller; 27. serial communication module; 28. touch screen; 29. switch; 30. battery cell; 31. external switch; 32. digital input module; 33. emergency stop button; 34. fan filter; 35. lighting lamp; 36. ventilation filter; 37. SOC control module. DETAILED DESCRIPTION

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

[0026] An all-vanadium redox flow battery SOC equalization monitoring and control system includes an equalizer control cabinet, which has three parts, namely a system architecture part, a control loop part, and a network architecture part, and the specific structure is as follows:

[0027] The system architecture part includes a DC contactor and a DC fuse. The DC contactor is divided into a total DC contactor 1 and a partial DC contactor 2. The SOC equalizer 5 outside the equalizer control cabinet is connected to the total DC contactor 1 inside the equalizer control cabinet through a cable. The total DC contactor 1 is connected to one end of the partial DC contactor 2 through a cable. The other end of the partial DC contactor 2 is connected to the DC fuse 3. The DC fuse 3 is connected to the external all-vanadium redox flow battery module 4.

[0028] The control loop 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 a cable. A cable connected to one end of the circuit breaker a 7 is additionally provided on the front end of the circuit breaker b 8. The other end of the circuit breaker a 7 is connected to the ground through a cable. The power supply 13 is also connected to one end of the DC circuit breaker 14 through a cable. The other end of the DC circuit breaker 14 is connected to the external contactor control loop power supply through a cable. 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 a cable. The other end of the fuse terminal 23 is connected to the electrical equipment outside the equalizer control cabinet.

[0029] The grid architecture part includes an Ethernet communication module 25, a CPU controller 26, a digital quantity input module 32, a touch screen 28, and a switch 29. The CPU controller 26 is connected with the SOC equalizer 5 and the battery unit 30 outside the equalizer control cabinet through the switch 29. The touch screen 28 is connected with the external switch 31 outside the equalizer control cabinet through the switch 29. The Ethernet communication module 25 is connected with the external switch 31 outside the equalizer control cabinet. A serial communication module 27 is arranged on the CPU controller 26, and the serial communication module 27 is connected with the SOC control module 37 outside the equalizer control cabinet.

[0030] The front cabinet door of the equalizer control cabinet is provided with a ventilation filter screen 36 and an emergency stop button 33. The rear cabinet door is provided with a fan filter screen 34. The top of the side surface is provided with an illuminating lamp 35. The inner side surface is further provided with a heater. The total DC contactor 1 is provided as two. The split DC contactor 2 is provided as 12. Each total DC contactor 1 is connected with six split DC contactors 2. The number of the DC fuse 3 is the same as that of the split DC contactor 2. The circuit breaker d10, the circuit breaker e11, and the circuit breaker f12 are connected in parallel between the circuit breaker b8 and the circuit breaker c9. The circuit breaker d10 is further connected with the socket 15. The circuit breaker e11 is further connected with the illuminating lamp 19 through the door control switch 16 and connected with the cooling fan 18 through the temperature control switch a17. The circuit breaker f12 is further connected with the heater 21 through the temperature control switch b20. The cooling fan 18 is provided as two. The heater 21 is provided as two. The number of the temperature control switch b20 is the same as that of the heater 21. The fuse terminal 23 is provided as 12 which are not shown in the figure and are connected with different electrical equipment outside the equalizer control cabinet. The lightning surge protector 24 is arranged on the cable grounding line of the circuit breaker a7. The DC circuit breaker 14 is provided as two which are connected with different contactor control loop power sources outside the equalizer control cabinet. The battery unit 30 is provided as four. The switch 29 is connected with the four battery units 30.

[0031] The system architecture is as follows Figure 1As shown, the equalization system can adapt two 6-string battery modules; the DC loop system architecture adopts DC contactor combined with DC fuse to connect to the battery module; the DC contactor main contact adopts non-polarity requirement application, which is more widely used and can ignore the current and wiring direction problems to realize charging or discharging requirements, and the DC contactor can be broken under load in emergency to stop the main contact without damaging the equipment, and the working and insulation voltage level of the DC contactor is the highest to meet DC1500V, #1 DC contactor 1KM and #2 DC contactor 2KM interlock and each DC contactor in each group interlocks to ensure that the equalization work will not have short circuit and misoperation; the DC fuse adopts knife type fast melting, which can quickly respond to breaking in case of overcurrent or short circuit and is convenient to replace for maintenance, and the DC fuse is provided with auxiliary contact and the auxiliary contact state is collected to the control system, and when the DC fuse fuse core is damaged, the auxiliary contact of the DC fuse moves, and the control system detects the fault state at the same time, and makes corresponding instructions according to the fault state.

[0032] The control loop is as shown in Figure 2 The micro-break of the control loop power supply adopts a wide voltage range type device with a maximum of 400VAC, and the control loop is provided with surge protection to prevent fluctuations and influences caused by overvoltage and overcurrent of the power supply voltage; the DC 24V power supply is provided with output insurance isolation function, and is provided with maintenance, lighting, ventilation, heat preservation and other equipment to maximize the demand for the operating environment of the control system.

[0033] The network architecture is as shown in Figure 3 The equalizer system network architecture controller is provided with double network segments to ensure data redundancy transmission to the upper computer; the communication with the equalizer adopts redundant communication to ensure more stable monitoring with the equalizer body, one of which is ModBus-RTU communication protocol, the interface is RS485, and the other is ModBus-TCP communication protocol, the interface is RJ45; all ModBus-TCP communication cables adopt super six category shielded network cables to increase the anti-interference ability. The equalization system is provided with a human-computer interface touch screen to realize human-computer interface operation control, data and state monitoring, etc.; the equalization system and the battery unit are provided with hardware dry contact safety interlocking, which will be disconnected when the battery system fails or emergency stops, thereby triggering the equalization system to stop to avoid misoperation; the equalization system and the equalizer are provided with hardware safety interlocking, which will be disconnected when the equalization system is in stop or failure, and the equalizer will be forced to stop when it loses the hardware dry contact interlocking.

[0034] The cabinet layout is as shown in Figure 4 The cabinet layout and structure standard are as follows: material: cold rolled steel plate, box plate thickness 2.0, door plate thickness 2.0, mounting plate is aluminum zinc coated plate, t=2, fixed with M8 standard screw, grade 8.8; protection level IP65, box color RAL9003 small orange pattern 60~120um;

[0035] Door lock MS748-3, with 4mm lock tongue; box and door welding M6*20 grounding nail; box zero row, ground row wiring bolt are M5, the inside of the door needs to be welded wire support; hinge is installed inside, fixed with two screws, model is Shengjiu CL201-3, the hinge hole in the box needs to be padded with a waterproof washer and treated with glue; the base is 150mm high, made of 4MM steel plate, the forklift stop plate of the base uses 304 stainless steel M6 internal hexagonal countersunk head bolt; each box door is provided with one Shengjiu door stopper TX92-2 (which can support the door at the maximum opening angle), installed at the lower part, the opening angle of the box door is 110 degrees; use PU foaming rubber strip for sealing; the unmarked dimensional tolerance is according to GB / T1804-2000 C level requirements; the guide rail in the cabinet needs to be flush with the wire slot according to the width of the cabinet body; the distribution box ensures the continuity of grounding; the exposed bolts are made of 304 stainless steel; equipped with daylight lamp and limiter; door structure, tempered glass window is installed on the small door, and wire support is provided on the door; wire sleeve specifications: opening hole 45, through hole 35, 40; the outer door is provided with machine steel.

[0036] The working mode and process of the balancing system are as follows:

[0037] 6.1 Precondition for using the balancing system:

[0038] ① The balancing control cabinet and the two sets of battery units communicate normally

[0039] ② The running state and SOC data of the corresponding battery read by communication are displayed normally

[0040] ③ The balancing control cabinet and the balancer communicate normally (the balancer state and data read are displayed normally)

[0041] ④ The balancing control cabinet has no communication failure, and all contactors and fuses have no failure

[0042] ⑤ The balancer body has no failure and is in normal shutdown or running state

[0043] ⑥ At least one set of battery unit is in normal running state

[0044] 6.2 Main strategy of the balancing system:

[0045] Take the difference between the maximum and minimum SOC values of the two sets of battery units, and adjust the battery modules in the set with the largest difference;

[0046] ① When the balancing system is in charging and discharging mode: the battery modules with the largest difference from the average SOC in the selected battery unit are balanced

[0047] ② When the balancing system is in discharging only mode: the maximum SOC battery modules in the selected battery unit are balanced

[0048] ③ When the balancing system is in charging mode only: the minimum SOC battery module in the selected battery unit is balanced

[0049] 6.3 Manual control of the balancing system:

[0050] ① Manual start process: confirm that the battery unit is in operation → the contactor corresponding to the SOC in the control cabinet is set to manual → click the main contactor of the corresponding contactor group of the corresponding battery unit to close → click the corresponding SOC from the contactor to close → both red lights are on → the busbar closing state of the corresponding group arrives →

busbar closing is complete

the balancing system starts successfully

[0051] ② Manual stop process: the control cabinet manual power setting is set to 0KW → the power real-time feedback display is also 0KW → click the balancing device stop button → the balancing device stop state arrives →

the balancing device stops successfully

the opening is complete

the balancing system stops successfully

[0052] 6.4 Automatic control of the balancing system:

[0053] ①Automatic start-stop process: ensure that all contactors in the control cabinet are in the open state → ensure that the balancer is in the normal stop state → ensure that the balancer is in the AC power mode → set the starting value of the balancing system (default 2%) → set the stopping value of the balancing system (default 1%) → set the balancing system inspection time (default 36 min) → set the balancing system intermittent time (default 3 min) → set the automatic state charge / discharge power (for example: -25KW / 25KW) → click the system automatic command → the system automatic state arrives → click the inspection timer start → the timer start state arrives → at this time the balancing system automatically selects the SOC battery module that meets the conditions in the two sets of battery units according to the inspection timer time to close the contactor → the contactor is closed → the balancer is started → the balancer runs to the

automatic start complete

automatic stop complete

balancing system infinite loop

[0054] If all systems are fault-free after the balancing system is switched to the automatic state, it will perform unattended self-control.

[0055] ②Exit automatic process: during automatic operation → click the inspection timer stop → the timer stop state arrives → click the system manual command → the system manual state arrives → at this time if the system is in the running state it will stop the balancer and then open the contactor. (The balancing system switches to the manual state and will be completely controlled by human initiative).

[0056] The above-described embodiments are only preferred embodiments of the present application, and not all the embodiments of the present application that can be implemented. Any obvious modifications made by those of ordinary skill in the art without departing from the principles and spirit of the present application should be considered within the scope of protection of the claims of the present application.

Claims

1. A system for SOC balancing monitoring and control of an all-vanadium redox flow battery, characterized by, The equalizer control cabinet comprises three parts, namely a system architecture part, a control loop part and a network architecture part. The system architecture part comprises a DC contactor and a DC fuse. The DC contactor comprises a total DC contactor (1) and a branch DC contactor (2). The SOC equalizer (5) outside the equalizer control cabinet is connected to the total DC contactor (1) inside the equalizer control cabinet through a cable. The total DC contactor (1) is connected to one end of the branch DC contactor (2) through a cable. The other end of the branch DC contactor (2) is connected to the DC fuse (3). The DC fuse (3) is connected to the external all-vanadium redox flow battery module (4). The control loop part comprises 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. The circuit breaker a (7) is connected to one end of the circuit breaker b (8) through a cable. The other end of the circuit breaker a (7) is connected to the ground through a cable. The power supply (13) is connected to one end of the DC circuit breaker (14) through a cable. The other end of the DC circuit breaker (14) is connected to the external contactor control loop power supply through a cable. The power supply (13) is connected to one end of the fuse terminal (23) connected in parallel with the DC circuit breaker (14) through a cable. The other end of the fuse terminal (23) is connected to the electrical equipment outside the equalizer control cabinet. The network architecture part comprises an Ethernet communication module (25), a CPU controller (26), a digital quantity 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). The serial communication module (27) is connected to the SOC control module (37) outside the equalizer control cabinet.

2. The system for SOC balancing monitoring and control of all vanadium redox flow battery as claimed in claim 1 wherein, The front cabinet door of the equalizer control cabinet is provided with a ventilation filter screen (36) and an emergency stop button (33). The rear cabinet door is provided with a fan filter screen (34). The top of the side surface is provided with a lighting lamp (35). The inner side surface is further provided with a heater.

3. The system for SOC balancing monitoring and control of all vanadium redox flow battery as claimed in claim 1 wherein, The total DC contactor (1) is provided with one or two. The branch DC contactor (2) is provided with 2-12. The number of the DC fuse (3) is the same as that of the branch DC contactor (2).

4. The system for SOC balancing monitoring and control of all vanadium redox flow battery as claimed in claim 1 wherein, The circuit breaker d (10) is further connected to the circuit breaker e (11) and the circuit breaker f (12) in parallel through a cable 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 the lighting lamp (19) through a door control switch (16) and connected to the cooling fan (18) through a temperature control switch a (17). The circuit breaker f (12) is further connected to the heater (21) through a temperature control switch b (20).

5. The system for SOC balancing monitoring and control of all vanadium redox flow battery as claimed in claim 4 wherein, The heat dissipation fan (18) is provided with multiple, the heater (21) is provided with multiple, the temperature control switch b (20) is provided with multiple same as the heater (21) quantity.

6. The system for SOC balancing monitoring and control of a vanadium redox flow battery of claim 1, wherein, The insurance terminal (23) is provided with multiple in parallel, and is connected with different electrical equipment outside the equalizer control cabinet respectively.

7. The system for SOC balancing monitoring and control of all vanadium redox flow battery as claimed in claim 1 wherein, The circuit breaker a (7) cable ground wire is provided with lightning surge protector (24).

8. The system for SOC balancing monitoring and control of all vanadium redox flow battery as claimed in claim 1 wherein, The direct current circuit breaker (14) is provided with multiple in parallel, and is connected with different contactor control loop power supply outside the equalizer control cabinet respectively.

9. The system for SOC balancing monitoring and control of all vanadium redox flow battery as claimed in claim 1 wherein, The battery unit (30) is provided with multiple, and the switch (29) is connected with multiple battery units (30) respectively.

Images