Error-proofing system and method for series-parallel connection control of power batteries

Abstract

The invention provides a mistake proofing system and method for series-parallel control of power batteries, belongs to the technical field of circuit protection of the power batteries, is used for series-parallel control of two power batteries, and comprises a battery management system, a series control module, a parallel control module, a series mistake proofing module and a parallel mistake proofing module. The battery management system outputs a control instruction to the series control module to control the two power batteries to be connected in series; and the series control module controls the parallel mistake proofing module to disconnect a control loop of the battery management system and the parallel control module. The battery management system outputs a control instruction to the parallel control module to control the two power batteries to be connected in parallel; the parallel control module controls the series connection mistake proofing module to disconnect a control loop of the battery management system and the series connection control module. According to the invention, a short-circuit fault caused by a circuit control error during series-parallel control of the two power batteries is prevented.

Description

Technical Field

[0001] The present invention belongs to the technical field of power battery circuit protection, and in particular, relates to an error-proofing system and method for series-parallel control of power batteries. Background Art

[0002] As the new energy vehicle industry accelerates its transition to an 800V high-voltage platform, power battery systems face an urgent need for compatibility with multiple voltage platforms. Current mainstream battery pack architectures generally suffer from platform rigidity: 400V battery systems struggle to match the energy needs of 800V supercharging stations, while global 800V solutions face pain points such as poor charging facility compatibility and surging component costs. The market urgently needs intelligent battery systems with flexible voltage switching capabilities to meet the needs of cross-platform vehicle development. Existing technologies have used relay arrays to reconfigure battery series and parallel topologies, but these solutions have exposed serious safety hazards in actual operating conditions. When the system switches between 400V and 800V modes, the high-voltage relay group may generate short-circuit faults due to incorrect closure of the high-voltage relays during the on-off timing control.

[0003] Chinese Patent 220797835U provides a switching device for adjusting the series and parallel connection of a battery system, including a drive module, a drive switch Q1, a drive switch Q2, a drive switch Q3, a drive switch Q4, a drive switch Q5, a drive switch Q6, a drive switch Q7, a drive switch Q8, and a drive switch Q9. By using this switching device for adjusting the series and parallel connection of a battery system, the same battery system can operate simultaneously at two or more voltage platforms. This device can be used to switch two or more battery packs in series and parallel, achieving high-power charging and discharging.

[0004] The existing technology does not consider the short circuit fault problem caused by the miscontrol of the high-voltage relay in the series-parallel control circuit of two power batteries. Summary of the Invention

[0005] The present invention aims to provide a system and method for preventing errors in the series-parallel control of power batteries, so as to solve the technical problem of short-circuit failure caused by miscontrol of a high-voltage relay in a series-parallel control circuit of two power batteries.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] The present invention provides an error prevention system for series-parallel control of power batteries, which is used for series-parallel control of two power batteries. The system includes a battery management system, a series control module, a parallel control module, a series error prevention module and a parallel error prevention module. The battery management system is connected to the series control module via the series error prevention module, and the battery management system is connected to the parallel control module via the parallel error prevention module. The output end of the series control module is connected to the input end of the parallel error prevention module, and the output end of the parallel control module is connected to the input end of the series error prevention module.

[0008] The series control module adopts series relays.

[0009] The parallel control module includes a first parallel relay and a second parallel relay.

[0010] The series error-proofing module includes a first normally closed relay and a second normally closed relay.

[0011] One end of the power supply end of the first normally closed relay is connected to the output end of the battery management system, and the other end is connected to the control end of the series relay. The control end of the first normally closed relay is connected in parallel to the control end of the first parallel relay; one end of the power supply end of the second normally closed relay is connected to the output end of the battery management system, and the other end is connected to the control end of the series relay. The control end of the second normally closed relay is connected in parallel to the control end of the second parallel relay.

[0012] The parallel error-proofing module includes a third normally closed relay and a fourth normally closed relay.

[0013] One end of the power supply end of the third normally closed relay is connected to the output end of the battery management system, and the other end is connected to the control end of the first parallel relay. The control end of the third normally closed relay is connected in parallel to the control end of the series relay; one end of the power supply end of the fourth normally closed relay is connected to the output end of the battery management system, and the other end is connected to the control end of the second parallel relay. The control end of the fourth normally closed relay is connected in parallel to the control end of the series relay.

[0014] The present invention provides a method for an error-proof system for series-parallel control of power batteries, which is used for series-parallel control of two power batteries:

[0015] The battery management system controls the series connection of the two power batteries by outputting control instructions to the series control module; the series control module controls the parallel error prevention module to disconnect the control loop between the battery management system and the parallel control module;

[0016] The battery management system controls the parallel connection of the two power batteries by outputting control instructions to the parallel control module; the parallel control module controls the series fault prevention module to disconnect the control loop between the battery management system and the series control module.

[0017] After the battery management system controls the series relay to close, the third normally closed relay in the parallel error prevention module disconnects the control circuit of the battery management system controlling the first parallel relay, and the fourth normally closed relay in the parallel error prevention module disconnects the control circuit of the battery management system controlling the second parallel relay.

[0018] After the battery management system controls the first parallel relay and the second parallel relay to close, the first normally closed relay in the series error prevention module disconnects the control circuit of the battery management system controlling the series relay, and the second normally closed relay in the series error prevention module disconnects the control circuit of the battery management system controlling the series relay.

[0019] The technical effects of the present invention are:

[0020] (1) The present invention eliminates the risk of short circuit caused by incorrect operation of series and parallel connections through hardware-level error prevention interlocking. When the battery management system controls the series relay to be closed, the control ends of the third and fourth normally closed relays are energized due to being connected in parallel with the series relay, and their power supply ends are disconnected, cutting off the battery management system's control loop for the first and second parallel relays. Even if the battery management system mistakenly sends a parallel instruction, the parallel relays cannot be closed, avoiding direct short circuit of the positive and negative poles due to parallel operation when the high-voltage batteries are connected in series. When the battery management system controls the first and second parallel relays to be closed, the control ends of the first and second normally closed relays are energized due to being connected in parallel with the parallel relay, and their power supply ends are disconnected, cutting off the battery management system's control loop for the series relays. At this time, the series relay cannot be triggered, preventing the positive and negative poles of the power battery from being short-circuited through the series loop due to series operation when the two batteries are connected in parallel.

[0021] (2) The present invention sets independent fuses in the series circuit and the parallel positive and negative circuits. When a battery or relay fails and causes overcurrent, the fuse blows quickly, cutting off the faulty circuit and avoiding safety accidents such as fire, which complies with the safety design specifications of high-voltage systems.

[0022] (3) The present invention uses a high-voltage normally open relay and a normally closed relay to cooperate with each other, and through the logical interlock of "control end power on-power end action", it forcibly blocks the error loop from the hardware level. Compared with simple software error prevention, it is more reliable and avoids safety hazards caused by program misjudgment.

[0023] (4) The system structure of the present invention is compact, and the layout of relays and fuses is clear. It can be directly integrated into the existing power battery management system without significantly changing the vehicle circuit architecture, and is suitable for new energy vehicles with dual battery platforms.

[0024] (5) The present invention is compatible with the fault tolerance specifications of multi-topology battery systems and the energy conversion efficiency requirements of power batteries. Under high surge impacts, it can reliably block the fault current conduction path, improving the safety factor compared to traditional solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] This manual includes the following drawings, which show the following contents:

[0026] Figure 1 This is a logical structure block diagram of a system and method for preventing errors in series and parallel control of power batteries according to the present invention;

[0027] Figure 2 A power battery series-parallel circuit diagram of a power battery series-parallel control error prevention system and method according to the present invention;

[0028] Figure 3 The connection relationship between the series-parallel relay and four normally closed relays of the error-proofing system and method for series-parallel control of power batteries of the present invention;

[0029] Figure 1 The symbols are: 1. Battery management system; 2. Series control module; 3. Parallel control module; 4. Series error prevention module; 5. Parallel error prevention module. DETAILED DESCRIPTION

[0030] The following is a further detailed description of the specific implementation methods of the present invention through the description of the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and to facilitate their implementation.

[0031] The present invention provides an error prevention system for series and parallel control of power batteries, which is used for series and parallel control of two power batteries. The system includes a battery management system 1, a series control module 2, a parallel control module 3, a series error prevention module 4 and a parallel error prevention module 5. The battery management system 1 is connected to the series control module 2 via the series error prevention module 4, and the battery management system 1 is connected to the parallel control module 3 via the parallel error prevention module 5. The output end of the series control module 2 is connected to the input end of the parallel error prevention module 5, and the output end of the parallel control module 3 is connected to the input end of the series error prevention module 4.

[0032] The series control module 2 uses a series relay. The parallel control module 3 includes a first parallel relay and a second parallel relay.

[0033] The series error-proofing module 4 includes a first normally closed relay and a second normally closed relay. One end of the power supply terminal of the first normally closed relay is connected to the output terminal of the battery management system 1, and the other end is connected to the control terminal of the series relay. The control terminal of the first normally closed relay is connected in parallel to the control terminal of the first parallel relay. One end of the power supply terminal of the second normally closed relay is connected to the output terminal of the battery management system 1, and the other end is connected to the control terminal of the series relay. The control terminal of the second normally closed relay is connected in parallel to the control terminal of the second parallel relay.

[0034] The parallel error-proofing module 5 includes a third normally closed relay and a fourth normally closed relay. One end of the power supply terminal of the third normally closed relay is connected to the output terminal of the battery management system 1, and the other end is connected to the control terminal of the first parallel relay. The control terminal of the third normally closed relay is connected in parallel to the control terminal of the series relay. One end of the power supply terminal of the fourth normally closed relay is connected to the output terminal of the battery management system 1, and the other end is connected to the control terminal of the second parallel relay. The control terminal of the fourth normally closed relay is connected in parallel to the control terminal of the series relay.

[0035] The present invention provides a method for an error-proof system for series-parallel control of power batteries, which is used for series-parallel control of two power batteries:

[0036] The battery management system 1 controls the two power batteries to be connected in series by outputting control instructions to the series control module 2; the series control module 2 controls the parallel error prevention module 5 to disconnect the control loop between the battery management system 1 and the parallel control module 3; the battery management system 1 controls the two power batteries to be connected in parallel by outputting control instructions to the parallel control module 3; the parallel control module 3 controls the series error prevention module to disconnect the control loop between the battery management system 1 and the series control module 2.

[0037] After the battery management system 1 controls the series relay to close, the third normally closed relay in the parallel error protection module 5 disconnects the control circuit for the battery management system 1 to control the first parallel relay, and the fourth normally closed relay in the parallel error protection module 5 disconnects the control circuit for the battery management system 1 to control the second parallel relay. After the battery management system 1 controls the first and second parallel relays to close, the first normally closed relay in the series error protection module 4 disconnects the control circuit for the battery management system 1 to control the series relay, and the second normally closed relay in the series error protection module 4 disconnects the control circuit for the battery management system 1 to control the series relay.

[0038] The following describes in detail an error-proofing system for controlling series and parallel connection of power batteries according to the present invention.

[0039] The present invention provides an error-proofing system for series-parallel control of power batteries for series-parallel control of two power batteries, including a battery management system 1, a series control module 2, a parallel control module 3, a series error-proofing module 4 and a parallel error-proofing module 5, wherein the battery management system (BMS) is used to control the series control module 2 and the parallel control module 3 to control the series and parallel connection of the two power batteries.

[0040] The series control module 2 uses a series relay to control the connection of the two power batteries in series. Specifically, the control terminal of the series relay is connected to the output terminal of the battery management system 1. When the battery management system 1 outputs a control signal, the control terminal of the series relay, i.e., the coil in the series controller, is energized, and the two power terminals of the series relay are turned on, connecting the two power batteries in series. In this embodiment of the present invention, the voltage level of the two power batteries is both 400V, and the series connection forms an 800V power supply.

[0041] The parallel control module 3 includes a first parallel relay and a second parallel relay, which are used to control the parallel connection of the two power batteries. Specifically, the control terminals of the first and second parallel relays are respectively connected to the output terminals of the battery management system 1. The battery management system 1 controls the closing of the power supply terminals of the first and second parallel relays through the control terminals of the first and second parallel relays. When the power supply terminals of the first and second parallel relays are closed, a parallel circuit is formed, and the two power batteries are connected in parallel.

[0042] It should be noted that the series relay, the first parallel relay, and the second parallel relay are all high-voltage normally open relays. When power is input to the control terminal, the power terminal closes, and the circuit connected to the relay is connected. The control terminal is the coil terminal, and the power terminal is the contact terminal.

[0043] The series fault prevention module 4 includes a first normally closed relay and a second normally closed relay, which are used to prevent the series control module 2 from being miscontrolled and causing a short circuit when two power batteries are connected in parallel. Specifically, after the battery management system 1 outputs control signals to the control terminals of the first and second parallel relays, the control terminal of the first normally closed relay is connected in parallel to the control terminal of the first parallel relay, and the control terminal of the second normally closed relay is connected in parallel to the control terminal of the second parallel relay. Upon receiving the control signals at the control terminals of the first and second parallel relays, the first and second normally closed relays respectively disconnect the power supply terminals of the first and second normally closed relays. Because the power supply terminals of the first and second normally closed relays are located within the control circuit of the battery management system 1 for the series relays, the series relays cannot be controlled to close by the battery management system 1 when the two power batteries are connected in parallel, ensuring circuit safety. Either the first or second normally closed relay, operating alone, can disconnect the control circuit of the battery management system 1 for the series relays.

[0044] The parallel error prevention module 5 includes a third normally closed relay and a fourth normally closed relay, which are used to prevent the parallel control module 3 from being mistakenly controlled and causing a circuit short circuit when two power batteries are connected in series. Specifically, when the battery management system 1 outputs a control signal to the control end of the series relay, because the control end of the third relay and the control end of the fourth relay are respectively connected in parallel to the control end of the series relay, when the two power batteries are connected in series, the power supply end of the third relay and the power supply end of the fourth relay are controlled to be disconnected, and the control circuit of the battery management system 1 for the first parallel relay and the control circuit of the battery management system 1 for the second parallel relay are disconnected. The power supply end of the first parallel relay and the power supply end of the second parallel relay cannot be controlled to close, preventing a short circuit fault caused by the closing of the parallel relay when the two power batteries are connected in parallel, thereby protecting the circuit safety when the two power batteries are connected in series.

[0045] The connection relationship of the present invention is described in detail below with reference to the accompanying drawings.

[0046] The negative electrode of power battery S1 is connected to the positive electrode of power battery S2 via a series relay (K2), and a fuse 3 is provided between power battery S1 and the series relay (K2). The negative electrode of power battery S1 is connected to the negative electrode of power battery S2 via a second parallel relay (K3), and a fuse 2 is provided between the negative electrode of power battery S1 and the second parallel relay (K3). The positive electrode of power battery S1 is connected to the positive electrode of power battery S2 via a first parallel relay (K1), and a fuse 1 is provided between the first parallel relay and power battery S2. The control end of the series relay (K2), the control end of the first parallel relay (K1), and the control end of the second parallel relay (K3) are respectively connected to the output end of the battery management system 1. One end of the power supply terminal of the first normally closed relay (K5) is connected to the output end of the battery management system 1, and the other end is connected to the control end of the series relay (K2). The control end of the first normally closed relay (K5) is connected in parallel to the control end of the first parallel relay (K1). One end of the power supply terminal of the second normally closed relay (K6) is connected to the output end of the battery management system 1, and the other end is connected to the control end of the series relay (K2). The control end of the second normally closed relay (K6) is connected in parallel to the control end of the second parallel relay (K3). One end of the power supply terminal of the third normally closed relay (K4) is connected to the output end of the battery management system 1, and the other end is connected to the control end of the first parallel relay (K1). The control end of the third normally closed relay (K4) is connected in parallel to the control end of the series relay (K2). One end of the power supply terminal of the fourth normally closed relay (K7) is connected to the output end of the battery management system 1, and the other end is connected to the control end of the second parallel relay (K3). The control end of the fourth normally closed relay (K7) is connected in parallel to the control end of the series relay (K2). Fuse 1, Fuse 2 and Fuse 3 are used to protect the vehicle safety by melting when a power battery failure occurs.

[0047] The following describes in detail a method for an error-proof system for controlling series and parallel connection of power batteries according to the present invention.

[0048] The battery management system 1 controls the two power batteries to be connected in series by outputting control instructions to the series control module 2. Specifically, the battery management system 1 controls the series relay to be closed, and the two power batteries are connected in series to form an 800V power supply. After the battery management system 1 controls the series relay to be closed, since the control end of the third normally closed relay is connected in parallel with the control end of the series relay, the power end of the third normally closed relay is disconnected, and the control circuit of the first parallel relay controlled by the battery management system 1 is disconnected; since the control end of the fourth normally closed relay is connected in parallel with the control end of the series relay, the power end of the fourth normally closed relay is disconnected, and the control circuit of the second parallel relay controlled by the battery management system 1 is disconnected. At this time, even if the battery management system 1 mistakenly outputs a control signal to the first parallel relay and the second parallel relay, the power end of the first parallel relay and the second parallel relay cannot be controlled to close, preventing the first parallel relay and the second parallel relay from closing and causing a short circuit fault in the circuit.

[0049] The battery management system 1 outputs control instructions to the parallel control module 3 to control the two power batteries to be connected in parallel. Specifically, the battery management system 1 outputs control signals to the control ends of the first parallel relay and the second parallel relay respectively, and the power supply ends of the first parallel relay and the second parallel relay are closed, and a parallel circuit of the two power batteries is formed. At this time, the operating voltage of the two power batteries after being connected in parallel is still 400V. Since the control end of the first normally closed relay is connected in parallel with the control end of the first parallel relay, and the control end of the second normally closed relay is connected in parallel with the control end of the second parallel relay, the power supply ends of the first normally closed relay and the second normally closed relay are both disconnected, and the battery management system 1 disconnects the control circuit of the series relay. At this time, even if the battery management system 1 outputs a control signal to the series relay, the series relay cannot be closed under control, thereby protecting the two power batteries from short circuit failures caused by the incorrect closure of the series relay when connected in parallel.

[0050] The present invention eliminates the risk of short circuit caused by incorrect operation of series and parallel connections through hardware-level error prevention interlocking. When the battery management system 1 controls the series relay to be closed, the control ends of the third and fourth normally closed relays are energized due to being connected in parallel with the series relay, and their power supply ends are disconnected, cutting off the control circuit of the battery management system 1 to the first and second parallel relays. Even if the battery management system 1 mistakenly sends a parallel instruction, the parallel relays cannot be closed, avoiding direct short circuit of the positive and negative poles due to parallel operation when the high-voltage batteries are connected in series. When the battery management system 1 controls the first and second parallel relays to be closed, the control ends of the first and second normally closed relays are energized due to being connected in parallel with the parallel relay, and their power supply ends are disconnected, cutting off the control circuit of the battery management system 1 to the series relay. At this time, the series relay cannot be triggered, preventing the positive and negative poles of the power battery from being short-circuited through the series circuit due to series operation when the two batteries are connected in parallel.

[0051] The present invention sets independent fuses in the series circuit and the parallel positive and negative circuits. When a battery or relay fails and causes overcurrent, the fuse quickly blows, cutting off the faulty circuit and avoiding safety accidents such as fire, which complies with the safety design specifications of high-voltage systems.

[0052] The present invention uses a high-voltage normally open relay and a normally closed relay in combination, and through the logical interlock of "control end power on-power end action", it forcibly blocks the error loop from the hardware level. Compared with simple software error prevention, it is more reliable and avoids safety hazards caused by program misjudgment.

[0053] The system structure of the present invention is compact, and the layout of relays and fuses is clear. It can be directly integrated into the existing power battery management system 1 without significantly changing the vehicle circuit architecture, and is suitable for new energy vehicles with dual battery platforms.

[0054] This invention adapts to the fault tolerance specifications of multi-topology battery systems and the energy conversion efficiency requirements of power batteries. Under high surge impacts, it can reliably block the fault current conduction path, improving the safety factor compared to traditional solutions.

[0055] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described method. Any non-substantial improvements made using the method concepts and technical solutions of the present invention, or any direct application of the above-described concepts and technical solutions to other situations without modification, fall within the scope of protection of the present invention.

Claims

1. A power battery series and parallel control error prevention system, used for series and parallel control of two power batteries, characterized by: It includes a battery management system, a series control module, a parallel control module, a series error prevention module and a parallel error prevention module. The battery management system is connected to the series control module through the series error prevention module, and the battery management system is connected to the parallel control module through the parallel error prevention module. The output end of the series control module is connected to the input end of the parallel error prevention module, and the output end of the parallel control module is connected to the input end of the series error prevention module.

2. The error-proofing system for series-parallel control of power batteries according to claim 1, used for series-parallel control of two power batteries, is characterized in that: The series control module adopts series relays.

3. The error-proofing system for series-parallel control of power batteries according to claim 1, used for series-parallel control of two power batteries, is characterized in that: The parallel control module includes a first parallel relay and a second parallel relay.

4. The error-proofing system for series-parallel control of power batteries according to claim 1, used for series-parallel control of two power batteries, is characterized in that: The series error-proofing module includes a first normally closed relay and a second normally closed relay.

5. A power battery series-parallel control error prevention system according to claim 2, 3 or 4, used for series-parallel control of two power batteries, characterized in that: One end of the power supply end of the first normally closed relay is connected to the output end of the battery management system, and the other end is connected to the control end of the series relay. The control end of the first normally closed relay is connected in parallel to the control end of the first parallel relay; one end of the power supply end of the second normally closed relay is connected to the output end of the battery management system, and the other end is connected to the control end of the series relay. The control end of the second normally closed relay is connected in parallel to the control end of the second parallel relay.

6. The error-proofing system for series-parallel control of power batteries according to claim 1, used for series-parallel control of two power batteries, characterized in that: The parallel error-proofing module includes a third normally closed relay and a fourth normally closed relay.

7. A power battery series-parallel control error prevention system according to claim 2, 3 or 6, used for series-parallel control of two power batteries, characterized in that: One end of the power supply end of the third normally closed relay is connected to the output end of the battery management system, and the other end is connected to the control end of the first parallel relay. The control end of the third normally closed relay is connected in parallel to the control end of the series relay; one end of the power supply end of the fourth normally closed relay is connected to the output end of the battery management system, and the other end is connected to the control end of the second parallel relay. The control end of the fourth normally closed relay is connected in parallel to the control end of the series relay.

8. A method for preventing errors in the series and parallel control of power batteries according to any one of claims 1 to 7, used for the series and parallel control of two power batteries, characterized in that: The battery management system controls the series connection of the two power batteries by outputting control instructions to the series control module; the series control module controls the parallel error prevention module to disconnect the control loop between the battery management system and the parallel control module; The battery management system controls the parallel connection of the two power batteries by outputting control instructions to the parallel control module; the parallel control module controls the series fault prevention module to disconnect the control loop between the battery management system and the series control module.

9. The method for preventing errors in a power battery series-parallel control system according to claim 8, which is used for controlling two power batteries in series-parallel, is characterized in that: After the battery management system controls the series relay to close, the third normally closed relay in the parallel error prevention module disconnects the control circuit of the battery management system controlling the first parallel relay, and the fourth normally closed relay in the parallel error prevention module disconnects the control circuit of the battery management system controlling the second parallel relay.

10. The method for preventing errors in a power battery series-parallel control system according to claim 8, which is used for controlling two power batteries in series-parallel, and is characterized in that: After the battery management system controls the first parallel relay and the second parallel relay to close, the first normally closed relay in the series error prevention module disconnects the control circuit of the battery management system controlling the series relay, and the second normally closed relay in the series error prevention module disconnects the control circuit of the battery management system controlling the series relay.

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