Series bypass protection device for management and control between battery clusters and control method

Abstract

The invention relates to a series bypass protection device for management and control between battery clusters and a control method, and the device comprises a solid-state switch which comprises two groups of sub-switches which are respectively connected in series with a positive electrode end and a negative electrode end of a battery cluster; the current sampling unit is connected in series with the battery cluster; the voltage sampling unit is connected with the compensation voltage source power converter in parallel; the semiconductor switch tube is connected with the compensation voltage source power converter in parallel; the solid-state switch is switched on and off according to the port current signal condition of the battery cluster, and the semiconductor switch tube is switched on and off according to the signal condition of the compensation voltage source power converter and the voltage signal condition of the output capacitor. Compared with the prior art, the method not only can compensate the bypass of the converter and protect the battery cluster and the converter device under the condition of partial short circuit of the system or device failure, but also can actively bypass and compensate the converter when the state difference of the parallel battery clusters is small, thereby avoiding control additional loss; and the safety and the economical efficiency of the compensation voltage type inter-cluster management and control energy storage system are improved.

Description

Technical Field

[0001] The present invention relates to the fields of power electronics technology and battery energy storage systems, and in particular to a series bypass protection device and a control method for battery cluster management and control. Background Art

[0002] The smallest basic unit of the electrochemical energy storage system is the battery cell. The system architecture is that several battery cells are connected in series to form a battery module, several battery modules are connected in series to form a battery cluster, and several battery clusters are connected in parallel to form an energy storage unit. The energy storage unit is connected to the power grid through an energy storage inverter and a step-up transformer.

[0003] Due to the inconsistency of battery cells in manufacturing, working environment, and aging, the open circuit voltage and equivalent series impedance of each battery cell are inconsistent. During the charge and discharge cycle of the energy storage system, the state of charge of different battery cells is different, and the port voltage of different battery cells is different. Since the battery module is composed of several battery cells connected in series, the port voltage of different battery modules is different. Since the battery cluster is composed of several battery modules connected in series, the port voltage of different battery clusters is different.

[0004] In the energy storage unit of the electrochemical energy storage system, several battery clusters with different port voltages are connected in parallel. The voltage difference between the battery clusters acts on the line impedance between the parallel battery clusters to generate current, which is defined as the circulating current between the parallel battery clusters. The circulating current consumes electrical energy through the line impedance, generates heat dissipation, causes losses, and reduces the overall charge and discharge cycle efficiency of the energy storage system.

[0005] In order to suppress the circulation between battery clusters and improve the system efficiency, it is necessary to manage the battery clusters in a refined manner. For example, the prior art patent CN114204647B provides a parallel battery cluster state management system solution, the structure of which is as follows: Figure 1 As shown, each battery cluster is connected in series with a voltage source and then in parallel with other battery clusters to form a common DC bus. The voltage source is the power converter for inter-cluster control. The voltage difference between battery clusters caused by the inconsistency of battery cells can be compensated by controlling the capacitor voltage in series with the power converter and the battery cluster, thereby suppressing the formation of circulating current between battery clusters. The power of the power converter for inter-cluster control is much smaller than the power of the battery cluster, and the proportion of the converter power is the ratio of the rated series compensation voltage to the rated voltage of the battery cluster.

[0006] Since the output capacitor of the power converter for inter-cluster control is connected in series with the battery cluster to realize the compensation voltage function, the series structure is prone to cause adverse effects between different modules when the module fails. The internal short circuit of the battery cluster will cause the DC bus voltage of the remaining battery clusters in parallel to act on the output capacitor of the power converter, and at the same time act on the high current and high voltage at the output end of the power converter; the DC bus short circuit of the parallel battery cluster will cause a reverse high voltage and short-circuit high current with the same voltage as the series battery cluster to act on the output capacitor of the power converter; the power converter failure will cause the battery cluster to be connected to the DC bus through the series capacitor, causing the DC circuit of the battery cluster to be disconnected.

[0007] Therefore, in order to realize all functions of the inter-cluster control power converter under the premise of safety and protect the parallel battery cluster system and the inter-cluster control power converter, the series bypass protection device at the converter is crucial. At present, there is no related technology for inter-cluster control bypass protection. Summary of the invention

[0008] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a series bypass protection device and control method for battery cluster management.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] A series bypass protection device for battery cluster management and control, wherein the battery cluster is connected in series with an output capacitor of a compensation voltage source power converter, and the compensation voltage source power converter is managed and controlled by a battery cluster central processor, and the series bypass protection device comprises:

[0011] A solid-state switch, including two groups of sub-switches, respectively connected in series to the positive electrode terminal and the negative electrode terminal of the battery cluster;

[0012] A current sampling unit, connected in series with the battery cluster, for acquiring a port current signal of the battery cluster;

[0013] A voltage sampling unit, connected in parallel with the compensation voltage source power converter, for acquiring a voltage signal of the output capacitor;

[0014] A semiconductor switch tube connected in parallel with the compensation voltage source power converter;

[0015] The solid-state switch is switched on and off according to the port current signal of the battery cluster, and the semiconductor switch tube is switched on and off according to the signal of the compensation voltage source power converter and the voltage signal of the output capacitor.

[0016] Preferably, a current sampling hardware protection circuit is further included, the current sampling unit is included in the current sampling hardware protection circuit, and the current sampling hardware protection circuit controls the on and off of the solid-state switch.

[0017] Preferably, it further comprises a voltage sampling hardware protection circuit, wherein the voltage sampling unit is included in the voltage sampling hardware protection circuit, and the voltage sampling hardware protection circuit controls the on and off of the semiconductor switch tube.

[0018] Preferably, the solid-state switch, current sampling unit, voltage sampling unit and semiconductor switch tube are respectively connected to the battery cluster central processor, and the battery cluster central processor obtains the signals of the compensation voltage source power converter, current sampling unit and voltage sampling unit, and can control the on and off of the solid-state switch and semiconductor switch tube after data processing.

[0019] Preferably, the semiconductor switch tube is a single silicon-based transistor, or a group of silicon-based transistors connected in series or in parallel.

[0020] Preferably, it further comprises a positive contactor and a negative contactor, which are respectively connected in series to the positive electrode terminal and the negative electrode terminal of the battery cluster.

[0021] A control method for inter-cluster battery management is applied to the above-mentioned series bypass protection device, including: an active bypass control process, a converter fault bypass protection control process, and a battery cluster short-circuit protection control process.

[0022] Preferably, the active bypass control process includes:

[0023] A minimum compensation voltage instruction is issued to the series-compensated voltage source power converter, and the voltage sampling unit obtains the compensation voltage signal of the output capacitor. When the compensation voltage reaches the minimum compensation voltage, the semiconductor switch tube is controlled to close to bypass the series-compensated voltage source power converter.

[0024] Preferably, the converter fault bypass protection control process includes:

[0025] When the battery cluster central processor obtains a fault signal of the series-compensated voltage source power converter, or when the voltage sampling unit obtains an abnormal voltage signal of the output capacitor, the semiconductor switch tube is controlled to close to bypass the series-compensated voltage source power converter.

[0026] Preferably, the battery cluster short circuit protection control process includes:

[0027] When the current sampling unit acquires an abnormal current signal of the battery cluster port, the solid-state switch is controlled to be disconnected to protect the series-compensated voltage source power converter.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. The series bypass protection device can not only bypass the converter in the case of partial short circuit or device failure in the system to protect the battery cluster and converter device, but also actively bypass the compensation converter when the state difference of the parallel battery cluster is small, avoiding additional control losses and improving the safety and economy of the compensation voltage type cluster control energy storage system;

[0030] 2. The present invention has fast over-current and over-voltage bypass capabilities and large current cut-off capabilities, which meet the safety requirements and economic development needs of the energy storage system, and safely and economically realize all the functions of the voltage-compensated inter-cluster control power converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a connection diagram of a battery cluster and a compensation voltage source converter in the prior art;

[0032] Figure 2 A schematic diagram of the structure of a series bypass protection device provided in an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of an active bypass control process provided by an embodiment of the present invention;

[0034] Figure 4 A schematic diagram of a converter fault bypass protection control process provided by an embodiment of the present invention;

[0035] Figure 5 A schematic diagram of a battery cluster short-circuit protection control process provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0037] In order to solve the existing technical problems, the present application proposes a series bypass protection device for inter-cluster control, which is used for bypassing and protecting the series compensation voltage source power converter 206 of the battery cluster. The battery cluster is connected in series with the output capacitor of the compensation voltage source power converter 206, and the compensation voltage source power converter 206 is managed and controlled by the battery cluster central processor 209 to form a group of battery clusters with control capabilities. The battery clusters with control capabilities are connected in parallel to form a group of energy storage units and have a common DC bus.

[0038] The series bypass protection device includes: a solid-state switch 201, including two groups of sub-switches, which are respectively connected in series to the positive electrode end and the negative electrode end of the battery cluster; a current sampling unit 202, which is connected in series with the battery cluster and is used to obtain the port charging and discharging current signal of the battery cluster; a voltage sampling unit 207, which is connected in parallel with the compensation voltage source power converter 206, and is used to obtain the voltage signal of the output capacitor; a semiconductor switch tube 208, which is connected in parallel with the compensation voltage source power converter 206.

[0039] The solid-state switch 201 is switched on and off according to the terminal current signal of the battery cluster, and the semiconductor switch tube 208 is switched on and off according to the signal of the compensation voltage source power converter 206 and the voltage signal of the output capacitor.

[0040] Optionally, the solid-state switch 201, the current sampling unit 202, the voltage sampling unit 207 and the semiconductor switch tube 208 are respectively connected to the battery cluster central processor 209. The battery cluster central processor 209 obtains and processes the data of the current sampling unit 202 and the voltage sampling unit 207. The battery cluster central processor 209 issues instructions to control the compensation voltage source power converter 206, and obtains and processes the state signal of the compensation voltage source power converter 206.

[0041] Optionally, the series bypass protection device further includes a current sampling hardware protection circuit, and the current sampling unit 202 is included in the current sampling hardware protection circuit. The solid-state switch 201 can be turned on or off by the battery cluster central processor 209 or the current sampling hardware protection circuit.

[0042] Optionally, the series bypass protection device may further include a voltage sampling hardware protection circuit, in which the voltage sampling unit 207 is included. The on or off of the semiconductor switch tube 208 may be controlled by the battery cluster central processor 209 or the voltage sampling hardware protection circuit.

[0043] The series bypass protection device may also include, but is not limited to, a fast fuse 203, a positive contactor 204, and a negative contactor 205. The positive contactor 204 and the negative contactor 205 are respectively connected in series to the positive electrode end and the negative electrode end of the battery cluster. The positive contactor 204 and the negative contactor 205 may be turned on or off by the battery cluster central processor 209 or the current sampling hardware protection circuit.

[0044] Optionally, the semiconductor switch tube 208 is a single silicon-based transistor, or a group of silicon-based transistors connected in series or in parallel.

[0045] This embodiment proposes a control method for inter-cluster battery management and control, which is applied to the above-mentioned series bypass protection device, including: an active bypass control process, a converter fault bypass protection control process, and a battery cluster short-circuit protection control process.

[0046] The active bypass control process includes: sending a minimum compensation voltage instruction to the series compensated voltage source power converter 206, and the voltage sampling unit 207 obtains the compensation voltage signal of the output capacitor. When it reaches the minimum compensation voltage, the semiconductor switch tube 208 is controlled to close, so that the series compensated voltage source power converter 206 is bypassed.

[0047] The converter fault bypass protection control process includes: when the battery cluster central processor 209 obtains the fault signal of the series compensation voltage source power converter 206, or when the voltage sampling unit 207 obtains the abnormal voltage signal of the output capacitor, the semiconductor switch tube 208 is controlled to close to bypass the series compensation voltage source power converter 206.

[0048] The battery cluster short circuit protection control process includes: when the current sampling unit 202 obtains an abnormal current signal of the battery cluster port, the solid-state switch 201 is controlled to be disconnected to achieve protection of the series compensation voltage source power converter 206 .

[0049] The series bypass protection device can not only bypass the converter in the event of a partial short circuit in the system or a device failure, protecting the parallel battery cluster system and the inter-cluster control power converter, but also has active bypass capability to meet the safety requirements and economic development needs of the energy storage system, thereby improving the economic benefits of the voltage-compensated inter-cluster control system.

[0050] Example

[0051] As a specific embodiment of the present invention, Figure 2 As shown, the battery cluster voltage is U Bat , the compensation voltage is U C The common DC bus voltage formed by the battery clusters with inter-cluster control capability connected in parallel is U o , the battery cluster charge and discharge current is I Bat , when the charge and discharge current is 0, U Bat +U C =U o .

[0052] The solid-state switch 201 includes two sets of two-port switches K1 and K2. One end of the two-port switch K1 is electrically connected to the positive electrode port of the battery cluster, and the other end is connected in series with the current sampling unit 202, the positive contactor 204 and the compensation voltage source power converter 206 in sequence; one end of the two-port switch K2 is electrically connected to the negative electrode port of the battery cluster, and the other end is connected in series with the fast fuse 203 and the negative contactor 205 in sequence. B It is a semiconductor switch tube 208.

[0053] In this embodiment, Figure 3 As shown, the active bypass control process of the series bypass protection device for compensating the voltage source power converter 206 includes the following process:

[0054] S301, the battery cluster central processor 209 issues a minimum compensation voltage instruction to the series compensation voltage source power converter 206;

[0055] The compensation voltage on the output capacitor of the converter gradually decreases to the minimum controllable compensation voltage value;

[0056] S302, the battery cluster central processor 209 obtains the compensation voltage signal of the converter output capacitor detected by the voltage sampling unit 207, and determines whether bypassing can be performed;

[0057] S303, after confirming that the voltage signal meets the conditions for converter bypass, the battery cluster central processor 209 sends a closing signal instruction to the semiconductor switch tube 208;

[0058] S304, the semiconductor switch tube 208 receives the closing signal and starts to operate, and completes closing after a certain period of time, and the power converter is bypassed.

[0059] In this embodiment, Figure 4 As shown, the series bypass protection device is used to compensate for the fault bypass protection control process of the voltage source power converter 206, which includes the following process:

[0060] S401, the battery cluster central processor 209 obtains the fault signal uploaded by the series compensation voltage source power converter 206, or the voltage sampling unit 207 detects the abnormal voltage signal of the output capacitor, and uploads it to the battery cluster central processor 209;

[0061] Optionally, the battery cluster central processor 209 may learn about the fault condition through communication, or may learn about the abnormal voltage fault condition through the voltage sampling unit 207;

[0062] S402, the battery cluster central processor 209 sends a closing signal instruction to the semiconductor switch tube 208;

[0063] Optionally, the battery cluster central processor 209 may determine the fault action and issue instructions through a software program, or may determine the fault action and issue instructions through a comparator of a hardware circuit;

[0064] S403, the semiconductor switch tube 208 receives the closing signal and starts to operate, and completes closing after a certain period of time, so that the faulty power converter is bypassed and the battery cluster can maintain normal operation.

[0065] In this embodiment, Figure 5 As shown, the series bypass protection device is used for the battery cluster short-circuit protection control process, which includes the following process:

[0066] S501, the current sampling unit 202 detects an abnormal current signal of the battery cluster charging and discharging current, and uploads it to the battery cluster central processor 209;

[0067] S502, the battery cluster central processor 209 receives and processes the abnormal signal;

[0068] S503, the battery cluster central processor 209 sends a circuit breaker signal instruction to the solid-state switch 201;

[0069] Optionally, the battery cluster central processor 209 may determine the fault action and issue instructions through a software program, or may determine the fault action and issue instructions through a comparator of a hardware circuit;

[0070] S504, the solid-state switch 201 receives the disconnection signal and starts to operate, and completes the disconnection after a certain period of time, the short-circuited battery cluster is disconnected, and the compensation voltage source power converter 206 is protected before overcurrent.

[0071] It should be noted that the present application can be implemented in software and / or a combination of software and hardware, for example, can be implemented using an application specific integrated circuit (ASIC), a general purpose computer or any other similar hardware device. In one embodiment, the software program of the present application can be executed by a processor to implement the steps or functions described above. Similarly, the software program of the present application (including relevant data structures) can be stored in a computer-readable recording medium, for example, a RAM memory, a magnetic or optical drive or a floppy disk and similar devices. In addition, some steps or functions of the present application can be implemented using hardware, for example, as a circuit that cooperates with a processor to perform each step or function.

[0072] The preferred specific embodiments of the present application are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present application without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art based on the concept of the present application through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A series bypass protection device for battery cluster management and control, wherein the battery cluster is connected in series with the output capacitor of a compensation voltage source power converter, and the compensation voltage source power converter is managed and controlled by a battery cluster central processor, characterized in that: The series bypass protection device comprises: A solid-state switch, including two groups of sub-switches, respectively connected in series to the positive electrode terminal and the negative electrode terminal of the battery cluster; A current sampling unit, connected in series with the battery cluster, for acquiring a port current signal of the battery cluster; A voltage sampling unit, connected in parallel with the compensation voltage source power converter, for acquiring a voltage signal of the output capacitor; A semiconductor switch tube connected in parallel with the compensation voltage source power converter; The solid-state switch is switched on and off according to the port current signal of the battery cluster, and the semiconductor switch tube is switched on and off according to the signal of the compensation voltage source power converter and the voltage signal of the output capacitor.

2. A series bypass protection device for battery cluster control according to claim 1, characterized in that: It also includes a current sampling hardware protection circuit, the current sampling unit is included in the current sampling hardware protection circuit, and the current sampling hardware protection circuit controls the on and off of the solid-state switch.

3. A series bypass protection device for battery cluster control according to claim 1, characterized in that: It also includes a voltage sampling hardware protection circuit, the voltage sampling unit is included in the voltage sampling hardware protection circuit, and the voltage sampling hardware protection circuit controls the on and off of the semiconductor switch tube.

4. A series bypass protection device for battery cluster control according to claim 1, 2 or 3, characterized in that: The solid-state switch, current sampling unit, voltage sampling unit and semiconductor switch tube are respectively connected to the battery cluster central processor, and the battery cluster central processor obtains the signals of the compensation voltage source power converter, current sampling unit and voltage sampling unit, and can control the on and off of the solid-state switch and semiconductor switch tube after data processing.

5. A series bypass protection device for battery cluster control according to claim 1, characterized in that: The semiconductor switch tube is a single silicon-based transistor, or a group of silicon-based transistors connected in series or in parallel.

6. A series bypass protection device for battery cluster control according to claim 1, characterized in that: It also includes a positive contactor and a negative contactor, which are respectively connected in series to the positive electrode terminal and the negative electrode terminal of the battery cluster.

7. A control method for battery cluster management, characterized in that: The series bypass protection device as claimed in any one of claims 1 to 6 comprises: an active bypass control process, a converter fault bypass protection control process, and a battery cluster short circuit protection control process.

8. A control method for battery cluster management and control according to claim 7, characterized in that: The active bypass control process includes: A minimum compensation voltage instruction is issued to the series-compensated voltage source power converter, and the voltage sampling unit obtains the compensation voltage signal of the output capacitor. When the compensation voltage reaches the minimum compensation voltage, the semiconductor switch tube is controlled to close to bypass the series-compensated voltage source power converter.

9. The control method for battery cluster management according to claim 7, characterized in that: The converter fault bypass protection control process includes: When the battery cluster central processor obtains a fault signal of the series-compensated voltage source power converter, or when the voltage sampling unit obtains an abnormal voltage signal of the output capacitor, the semiconductor switch tube is controlled to close to bypass the series-compensated voltage source power converter.

10. The control method for battery cluster management according to claim 7, characterized in that: The battery cluster short circuit protection control process includes: When the current sampling unit acquires an abnormal current signal of the battery cluster port, the solid-state switch is controlled to be disconnected to protect the series-compensated voltage source power converter.

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