Regulation and control method of all-vanadium redox flow battery management system for standby power supply

Abstract

The invention discloses a regulation and control method of an all-vanadium redox flow battery management system for a standby power supply. The all-vanadium redox flow battery management system comprises a management system, a battery system and a battery auxiliary system which are electrically connected with one another, the battery system comprises at least one battery subsystem; the battery auxiliary system comprises a conversion system, and the conversion system is a direct current-alternating current change system and / or a direct current-direct current change system; the all-vanadium redox flow battery management system of the power supply preferentially uses the mains supply to supply power to the battery auxiliary system, and when the mains supply interrupts power supply, the management system controls the battery system to discharge with power Pbath and supply power to the battery auxiliary system through the conversion system. A hardware connection scheme and a reasonable management strategy are provided for applying the all-vanadium redox flow battery system to a standby power supply scene, the auxiliary power consumption of the battery system is effectively reduced, the system efficiency is greatly improved, and the development of the all-vanadium redox flow battery is promoted.

Description

Technical Field

[0001] The present application relates to a regulation method for a full vanadium redox flow battery management system for a backup power supply, belonging to the technical field of electrochemistry. Background Art

[0002] China has a vast territory and is rich in solar and wind energy resources. However, these natural energies have characteristics such as intermittency and volatility, and it will encounter great difficulties to directly connect to the power grid and must be smoothed first. At the same time, there are often mismatches between power supply and demand in terms of time and space, showing phenomena such as peak-valley bands and regional imbalance. An important way to solve the above problems is energy storage technology. In particular, electrochemical energy storage also has advantages such as high efficiency, fast response speed, and being unrestricted by geographical environment, and is suitable for the smoothing of wind and solar power generation on the supply side and also for the power management on the demand side. Compared with other electrochemical energy storage technologies, the full vanadium redox flow battery has characteristics such as intrinsic safety, extremely long cycle life, and decoupling of capacity and power, and is particularly suitable for large-scale energy storage power stations.

[0003] A backup power supply is a safety guarantee device, whose function is to ensure the normal operation of equipment through the power supply of the backup power supply in the case of a main power failure or power outage, and avoid adverse consequences such as data loss and equipment shutdown caused by power failures. Backup power supplies are widely used in important industries such as telecommunications, transportation, finance, medical care, and communication, and are also adopted by more and more power stations and small enterprises. Compared with traditional backup power supplies, the power and capacity of the full vanadium redox flow battery can be independent, and can be flexibly configured and expanded. Due to its generally large scale, it is particularly suitable for large backup power demand sites. The state of charge of the battery needs to be controlled within a certain range. How to achieve the balance of timely response, service life, and high energy efficiency is still a problem faced by the full vanadium redox flow battery in the backup power supply scenario. Summary of the Invention

[0004] According to one aspect of the present application, a regulation method for a full vanadium redox flow battery management system for a backup power supply is provided, which solves the aforementioned problems, that is, it is necessary to ensure that the battery system remains powered when the mains power supply is interrupted unexpectedly, and at the same time, it is necessary to take into account the impact of long-term operation in a high state of charge on the service life of the battery, and maximize the energy efficiency of the battery system.

[0005] The present application adopts the following technical solutions:

[0006] A regulation method for a full vanadium redox flow battery management system for a backup power supply, the full vanadium redox flow battery management system includes a management system, a battery system, and a battery auxiliary system that are electrically connected to each other;

[0007] The battery system includes at least 1 battery subsystem;

[0008] The battery auxiliary system includes a conversion system, which is a DC-AC conversion system and / or a DC-DC conversion system;

[0009] The all-vanadium redox flow battery management system of the power supply preferentially uses the mains power to supply power to the battery auxiliary system. When the mains power supply is interrupted, the management system controls the battery system to discharge at a power of Pbattery and supply power to the battery auxiliary system through the conversion system;

[0010] When Pbattery ≤ P1, the battery system does not start;

[0011] When P1 < Pbattery ≤ Pn, 1 battery subsystem is started;

[0012] When P1 + (x - 1)Pn < Pbattery ≤ xPn, x battery subsystems are started, where 1 < x;

[0013] Wherein, P1 is the power consumption of the battery auxiliary system, and Pn is the rated power of the battery subsystem.

[0014] In the present application, the number x of the started battery subsystems is theoretically not limited.

[0015] Optionally, the battery subsystem includes a positive and negative circulation pump for controlling the variable-frequency operation of the battery subsystem;

[0016] When the battery system operates at variable frequency, the management system detects the charge and discharge current Ibattery value of the battery subsystem or the discharge power Pbattery value of the battery subsystem and regulates the frequency fpump value of the positive and negative circulation pump;

[0017] When the management system detects the charge and discharge current Ibattery value of the battery subsystem and regulates the frequency fpump value of the positive and negative circulation pump:

[0018] When Ibattery ≥ 0, fpump = F3;

[0019] When I1 < Ibattery < 0, fpump = F2;

[0020] When Ibattery < I1, fpump = F1;

[0021] 0 < I1 < I n ,I n is the rated current of the battery subsystem;

[0022] When the management system detects the discharge power Pbattery value of the battery subsystem and then regulates the frequency fpump value of the positive and negative circulation pump:

[0023] When P1 < Pbattery ≤ 0.5Pn, fpump = F2;

[0024] When 0.5Pn < Pbattery ≤ Pn, fpump = F1;

[0025] Wherein, F3 < F2 < F1, 0 ≤ F3 ≤ 20Hz, 0 < F1 ≤ 50Hz.

[0026] Optionally, the battery auxiliary system further includes a heat exchange system, a circulation system, a lighting system, a control system, and a standby circuit connected in parallel to the bus;

[0027] One end of the conversion system is electrically connected to the positive and negative electrodes of the battery subsystem, and a power supply inlet line is led out from the other end of the conversion system. The power supply inlet line is electrically connected to the bus through a circuit breaker, and the bus is electrically connected to the heat exchange system, the circulation system, the lighting system, the control system, and the standby circuit respectively through circuit breakers.

[0028] Optionally, the management system includes a central processing unit for data processing and a data acquisition and storage device.

[0029] Optionally, the functions of the central processing unit include controlling the discharge power of the battery system, variable frequency speed regulation, and valve drive; the data acquisition and storage device is used to detect the charge and discharge current, voltage, pressure flow, temperature level, pump current, and rotation speed of the battery subsystem.

[0030] In this application, the management system real-time collects the operating parameters of the battery system and has a data storage function. It can record important parameters such as pipeline flow, pipeline pressure, electrolyte temperature, positive and negative electrode storage tank levels, circulation pump current, circulation pump rotation speed, battery system voltage, current, state of charge, and alarm information. The storage time interval can be freely set by the user and supports the data export function, which is convenient for later data induction and summary. It can also provide an alarm and fault protection function for the operation of the battery system. When the operating parameters of the battery system are abnormal or exceed the limit, the battery management gives an audible and visual alarm to remind the user. When the battery system fails, the battery management system actively stops the battery system and cuts off the main charge and discharge circuit, effectively protecting the battery and ensuring that when a certain device of the battery system fails, the device power supply is cut off immediately to ensure the safety of the battery system. In addition, the all-vanadium redox flow battery management system provided in this application has good compatibility, supports a variety of industrial general communication interfaces, and can exchange data with third-party devices

[0031] Optionally, the rated power Pn of the battery subsystem takes a value of: 0 < Pn ≤ 500kW.

[0032] Optionally, the capacity of the battery subsystem is less than or equal to 2.5MWh.

[0033] Optionally, the power consumption P1 of the battery auxiliary system is: 0 < P1 ≤ 30 kW.

[0034] The beneficial effects that can be produced by this application include:

[0035] The method for regulating and controlling the all-vanadium redox flow battery management system for standby power supply provided by this application realizes the standby power supply function of the all-vanadium redox flow battery system, and the circulating pump operates with variable frequency speed regulation according to the actual working conditions, reducing the auxiliary power consumption of the battery system and improving the energy efficiency of the battery system. When the power of the important load is not large, some battery subsystems can be started, which can not only reduce the power consumption of the battery system, but also achieve reasonable scheduling, extend the service life of the battery subsystems, greatly improve the system efficiency, provide a hardware connection scheme and a reasonable management strategy for the application of the all-vanadium redox flow battery system in the standby power supply scenario, and promote the development of the all-vanadium redox flow battery. Description of the Drawings

[0036] Figure 1 It is a schematic diagram of the functions of the battery management system in the embodiment of this application.

[0037] Figure 2 It is a wiring diagram of the power consumption of the battery auxiliary system in the embodiment of this application.

[0038] Figure 3 It is a flow chart of the call of the battery subsystems in the embodiment of this application.

[0039] Figure 4 It is a flow chart of the variable frequency operation of the battery system in the embodiment of this application. Detailed Embodiments

[0040] The following describes this application in detail with reference to the embodiments, but this application is not limited to these embodiments.

[0041] Unless otherwise specified, the raw materials in the embodiments of this application are all purchased through commercial channels.

[0042] Embodiment 1

[0043] The all-vanadium redox flow battery management system for standby power supply includes a management system, a battery system, and a battery auxiliary system that are electrically connected to each other. The management system, as Figure 1 shown, includes a central processing unit, transmitters such as voltage, current, temperature, flow rate, and pressure, charge protection, discharge protection, and single-cell voltage anomaly protection, etc., and has a human-machine interface display and supports functions such as Ethernet communication. The battery system is a set of 1 MW / 6 MWh all-vanadium redox flow battery system, which is composed of 4 sets of 250 kW / 1.5 MWh battery subsystems. As Figure 2As shown in the figure, the battery subsystem powers auxiliary devices through a DC / AC inverter. The auxiliary devices include a heat exchange system, a circulation system, a lighting system, a control system, and a standby circuit that are connected in parallel to the busbar. One end of the DC / AC inverter is electrically connected to the positive and negative poles of the battery subsystem. A power supply incoming line is led out from the other end of the change system, and the power supply incoming line is electrically connected to the busbar through a circuit breaker. The busbar is electrically connected to the auxiliary devices through a circuit breaker. The power consumption of a single set of battery auxiliary system is about 25kW. Among them, the DC / AC device adopts two-way power supply, preferentially using the commercial power. When the commercial power is interrupted, it automatically and seamlessly switches to battery power supply. The positive and negative circulation pumps of each 250kW battery subsystem adopt variable frequency speed control.

[0044] When the commercial power supply is interrupted, the 4 battery subsystems operate in the standby power supply state. At this time, if the load power is less than the rated power of 250kW, only one set of battery subsystem is started, and the other three sets of battery subsystems operate at a low frequency. At this time, if the load power is less than 1 / 2 of the rated power, the electrolyte circulation pump operates at 25Hz. If the load power is greater than 1 / 2 of the rated power and less than the rated power of the battery system, the electrolyte circulation pump operates at 35Hz. The above method realizes the standby power supply function of the all-vanadium redox flow battery system, effectively reduces the auxiliary power consumption of the battery system, and greatly improves the system efficiency.

[0045] As described above, these are only several embodiments of the present application, and do not impose any form of limitation on the present application. Although the present application is disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, makes some changes or modifications using the technical content disclosed above, which are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. A control method for a vanadium redox flow battery management system for backup power supply, characterized in that, The all-vanadium redox flow battery management system includes a management system, a battery system, and a battery auxiliary system that are electrically connected to each other; The battery system includes at least one battery subsystem; The battery auxiliary system includes a conversion system, and the conversion system is a DC-AC conversion system and / or a DC-DC conversion system; The all-vanadium redox flow battery management system of the power supply preferentially uses the commercial power to supply power to the battery auxiliary system. When the commercial power supply is interrupted, the management system controls the battery system to discharge at a power of Pbattery and supply power to the battery auxiliary system through the conversion system; When Pbattery ≤ P1, the battery system does not start; When P1 < Pbattery ≤ Pn, one battery subsystem is started; When P1 + (x - 1)Pn < Pbattery ≤ xPn, x battery subsystems are started, where 1 < x; Among them, P1 is the power consumption of the battery auxiliary system, and Pn is the rated power of the battery subsystem.

2. The method according to claim 1, characterized in that, The battery subsystem includes a positive and negative circulation pump for controlling the variable-frequency operation of the battery subsystem; When the battery system operates at variable frequency, the management system detects the charge and discharge current Ibattery value of the battery subsystem or the discharge power Pbattery value of the battery subsystem and regulates the frequency fpump value of the positive and negative circulation pump; When the management system detects the charge and discharge current Ibattery value of the battery subsystem and regulates the frequency fpump value of the positive and negative circulation pump: When Ibattery ≥ 0, fpump = F3; When I1 < Ibattery < 0, fpump = F2; When Ibattery < I1, fpump = F1; 0 < I1 < I n , I n is the rated current of the battery subsystem; When the management system detects the discharge power Pbattery value of the battery subsystem and then regulates the frequency fpump value of the positive and negative circulation pump: When P1 < Pbattery ≤ 0.5Pn, fpump = F2; When 0.5Pn < Pbattery ≤ Pn, fpump = F1; Among them, F3 < F2 < F1, 0 ≤ F3 ≤ 20Hz, 0 < F1 ≤ 50Hz.

3. The method according to claim 1, characterized in that, The battery auxiliary system also includes a heat exchange system, a circulation system, a lighting system, a control system, and a standby circuit connected in parallel to the bus; One end of the conversion system is electrically connected to the positive and negative poles of the battery subsystem. A power supply inlet line is led out from the other end of the conversion system, and the power supply inlet line is electrically connected to the bus through a circuit breaker. The bus is electrically connected to the heat exchange system, the circulation system, the lighting system, the control system, and the standby circuit through circuit breakers respectively.

4. The method according to claim 1, characterized in that, The management system includes a central processing unit for data processing and a data acquisition and storage device.

5. The method according to claim 1, characterized in that, The value of the rated power Pn of the battery subsystem is: 0 < Pn ≤ 500kW.

6. The method according to claim 1, characterized in that, The capacity of the battery subsystem is less than or equal to 2.5MWh.

7. The method according to claim 1, characterized in that, The value of the power consumption P1 of the battery auxiliary system is: 0 < P1 ≤ 30kW.

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