High-voltage energy storage battery system protection circuit and battery system

Abstract

The utility model discloses a high-voltage energy storage battery system protection circuit and a battery system. The circuit comprises a controller, a plurality of charging modules and a plurality of discharging modules. The controller is connected with the plurality of charging modules and the plurality of discharging modules, the charging modules are connected with the batteries and the peripheral port, the discharging modules are connected with the batteries and the peripheral port, the discharging modules are connected with the charging modules in parallel, the number of the charging modules and the discharging modules is equal to the number of the batteries, and the peripheral port is connected with a power supply or a load; and the controller is used for detecting the residual electric quantity of the battery, and controlling the charging module connected with the battery to be disconnected when detecting that the residual electric quantity is greater than preset electric quantity. When the battery is fully charged or the load is not controlled, the controller can control the charging module to be disconnected so as to ensure that the safety risk of the system is not caused by overcharge, and when the discharge needs to be immediately converted, the discharge is directly output through the discharge module, so that the safety is ensured, and the system is not down.

Description

Technical Field

[0001] This utility model relates to the field of battery control technology, and in particular to a protection circuit and battery system for a high-voltage energy storage battery system. Background Technology

[0002] Current control methods for charge and discharge circuits are relatively simple. For a single cell cluster, there is one contactor in each of the positive and negative circuits. During normal operation, the protection function for distinguishing charge and discharge modes cannot be implemented. This means that if one contactor disconnects, the system will crash, posing a serious risk to system stability. Furthermore, this approach is not suitable for the float charging equalization logic at the end of a single cell cluster. The solution needs to reduce the overall charging voltage to ensure consistency at the end of the system's charging and to support the current limiting control logic. For systems with multiple cascaded cells, this method reduces the accuracy of SOC uploads to the stack-level system and decreases the charge and discharge capacity. Utility Model Content

[0003] The main purpose of this invention is to propose a protection circuit and battery system for a high-voltage energy storage battery system, which aims to solve the problem that the existing charging circuit is single and cannot distinguish between charging and discharging modes.

[0004] To achieve the above objectives, the high-voltage energy storage battery system protection circuit proposed in this utility model includes: a controller, multiple charging modules, and multiple discharging modules;

[0005] The controller connects to multiple charging modules and multiple discharging modules. The charging modules are connected to the battery and peripheral ports. The discharging modules are connected to the battery and peripheral ports. The discharging modules are connected in parallel with the charging modules. The number of charging modules and discharging modules is equal to the number of batteries. The peripheral ports are connected to a power source or a load.

[0006] The charging module is used to control the power supply to charge the battery when the power is connected to the peripheral port;

[0007] The controller is used to detect the remaining power of the battery, and when the remaining power is detected to be greater than a preset power, it controls the charging module connected to the battery to disconnect.

[0008] The discharge module is used to control the battery to supply power to the load when the load is connected to the peripheral port.

[0009] In one embodiment, the circuit further includes: a protection module and a current shunt module;

[0010] The protection module is connected to the peripheral interface, the charging module, the discharging module and the battery, and the current shunt module is connected to the peripheral interface and the battery;

[0011] The protection module is used to disconnect the connection between the battery and the peripheral port when an overcurrent is detected.

[0012] The current shunt module is used to control the charging current of the charging module.

[0013] In one embodiment, the controller is further configured to control the discharge module to disconnect when the load fault is detected.

[0014] In one embodiment, the controller is configured to request a preset voltage from the power source for charging, and reduce the charging current by a preset number of times, so that the battery is charged with a preset current;

[0015] The controller is also configured to eliminate the voltage difference between the high-voltage battery and the remaining battery by discharge equalization when the battery is charged with a preset current.

[0016] In one embodiment, the controller is configured to reduce the charging current of the power supply when the charging module of one of the batteries is disconnected, and continue to charge the remaining batteries until the remaining charge of all batteries is greater than the preset charge.

[0017] In one embodiment, the discharge module includes: a first diode and a first contactor;

[0018] The anode of the first diode is connected to the positive terminal of the battery and the discharge module, the cathode of the first diode is connected to the first port of the first contactor and the discharge module, and the second port of the first contactor is connected to the positive terminal of the peripheral port and the discharge module.

[0019] In one embodiment, the charging module includes: a second diode and a second contactor;

[0020] The first end of the second contactor is connected to the anode of the first diode and the positive terminal of the battery. The second end of the second contactor is connected to the cathode of the first diode, the cathode of the second diode, and the first end of the first contactor. The anode of the second diode is connected to the second end of the first contactor and the positive terminal of the peripheral port.

[0021] In one embodiment, the protection module includes: a fuse, a first resistor, a third contactor, and a circuit breaker;

[0022] One end of the fuse is connected to the positive terminal of the battery, and the other end of the fuse is connected to the anode of the first diode, the first terminal of the second contactor, and one end of the first resistor. The other end of the first resistor is connected to the first terminal of the third contactor. The second terminal of the third contactor is connected to the second terminal of the first contactor, the anode of the second diode, and the first input terminal of the circuit breaker. The first output terminal of the circuit breaker is connected to the second output terminal of the circuit breaker. The second input terminal of the circuit breaker is connected to the third input terminal of the circuit breaker. The third output terminal of the circuit breaker is connected to the positive terminal of the peripheral port. The fourth input terminal of the circuit breaker is connected to the shunt module, and the fourth output terminal of the circuit breaker is connected to the negative terminal of the peripheral port.

[0023] In one embodiment, the shunt module includes: a shunt and a fourth contactor;

[0024] One end of the shunt is connected to the negative terminal of the battery, and the other end of the shunt is connected to the first port of the fourth contactor. The second port of the fourth contactor is connected to the fourth input terminal of the circuit breaker.

[0025] This utility model also proposes a battery system, which includes the high-voltage energy storage battery system protection circuit as described above.

[0026] This utility model discloses a protection circuit and a battery system for a high-voltage energy storage battery system. The protection circuit includes a controller, multiple charging modules, and multiple discharging modules. The controller connects to the multiple charging modules and the multiple discharging modules. Each charging module connects to a battery and an external port, and each discharging module connects to a battery and an external port. The discharging modules are connected in parallel with the charging modules, and the number of charging and discharging modules equals the number of batteries. The external ports are connected to a power source or a load. The charging modules control the power source to charge the battery when a power source is connected to the external port. The controller detects the remaining battery charge and, when the remaining charge exceeds a preset limit, controls the charging modules connected to the battery to disconnect. The discharging modules control the battery to supply power to the load when a load is connected to the external port. When the battery is fully charged or the load is uncontrolled, the charging modules can be disconnected to prevent overcharging and ensure the system does not pose a safety risk. Furthermore, when immediate discharge is required, the discharging modules directly output discharge, ensuring safety without causing system downtime. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the structure of the first embodiment of the protection circuit for the high-voltage energy storage battery system provided by this utility model;

[0029] Figure 2 A schematic diagram of the module of the first embodiment of the protection circuit for the high-voltage energy storage battery system provided by this utility model;

[0030] Figure 3 A circuit diagram of the second embodiment of the high-voltage energy storage battery system protection circuit provided by this utility model;

[0031] Figure 4 A flowchart illustrating the third embodiment of the high-voltage energy storage battery system protection circuit provided by this utility model;

[0032] Figure 5 Another schematic diagram of the third embodiment of the high-voltage energy storage battery system protection circuit provided by this utility model.

[0033] Explanation of icon numbers:

[0034] label name label name 100 Charging module D1~D2 First to second diodes 200 controller R1 First resistor 300 Discharge module C1~C4 First to fourth contactors 400 Peripheral ports 500 Battery

[0035] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0037] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0038] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0039] Current charging and discharging circuit control is relatively simple. For a single battery cluster, for example... Figure 1 As shown, there is a contactor in each of the positive and negative circuits. During normal operation, the protection function cannot distinguish between charging and discharging modes, which means that if one of the contactors disconnects, the system will crash, posing a serious risk to the system's stability. It is not friendly to the floating charge equalization logic at the charging end of a single cluster of cells, and the overall charging voltage needs to be reduced to ensure the consistency of the charging end of the system and the control logic for charging current limiting. For systems with multiple clusters of cells cascaded, this solution reduces the accuracy of the SOC upload of the stack-level system and reduces the charging and discharging capacity.

[0040] In multi-cluster cascaded battery systems, there is a problem with SOC (State of Charge) reporting. Because the main positive / main negative contactors cannot be disconnected in the system, the system design must ensure that the stack-level system stops operating when any cluster reaches its charge / discharge SOC limit. At this time, the SOC value reported to the monitoring system must be the lowest discharge SOC and the highest charge SOC, which will cause the overall SOC value to be unable to be collected and calculated using the SOC values ​​of other clusters, resulting in an inaccurate SOC (in actual stack-level systems, the weakest cluster in the "barrel effect" is mostly used as the system's SOC reporting, that is, the lowest SOC is reported during discharge to cut off discharge early, and the highest SOC is reported during charging to cut off charging early).

[0041] In multi-cluster cascaded battery systems, there is a problem of reduced charge / discharge capacity. As shown in the SOC upload issue above, the original main positive / main negative contactor scheme at the charging end of the cascaded system requires the entire system to be shut down when one cluster is fully charged. Otherwise, when the contactor of the fully charged cluster is disconnected, the system cannot quickly switch to discharge, leading to overcurrent problems in other clusters. Therefore, to ensure that multiple clusters are fully charged together in a cascaded system, only one cluster can be fully charged, and the other clusters will stop charging. This results in the other clusters not being able to reach full charge, reducing the charging capacity, and consequently causing a loss of discharge capacity for the entire stack-level system.

[0042] like Figure 2 As shown, this utility model discloses a high-voltage energy storage battery system protection circuit and a therapeutic device. The high-voltage energy storage battery system protection circuit includes: a controller 200, multiple charging modules 100, and multiple discharging modules 300. The controller connects to the multiple charging modules and the multiple discharging modules. Each charging module connects to a battery 500 and an external port 400. Each discharging module connects to the battery and the external port. The discharging modules are connected in parallel with the charging modules. The number of charging modules and discharging modules is equal to the number of batteries. The external port is connected to a power source or a load. The charging modules are used to control the power source to charge the battery when a power source is connected to the external port. The controller is used to detect the remaining power of the battery. When the remaining power is detected to be greater than a preset power, it controls the charging modules connected to the battery to disconnect. The discharging modules are used to control the battery to supply power to the load when a load is connected to the external port.

[0043] Understandably, the preset charge level is the battery's full charge level, i.e., 100%. When a single battery cluster works together with loads such as PCS, at the end of the charging process, the charging contactor can be disconnected when the battery is fully charged or the load becomes uncontrollable. This ensures that the system will not cause safety risks due to overcharging. Furthermore, when immediate discharge is required, the discharge module can directly output discharge, ensuring both safety and preventing system shutdown.

[0044] It should be noted that when one battery cluster is fully charged, charging can be stopped by disconnecting its charging module, thus ensuring that other battery clusters that are not fully charged can continue to charge, so that each battery cluster can reach a fully charged state and maximize the charging capacity of all clusters. This ensures that the stack system has sufficient capacity during discharge and can release more electricity.

[0045] Specifically, charging module 100 is connected in parallel between battery 500 and peripheral port 400, supporting independent charging control. Discharging module 300 is connected in parallel between battery and peripheral port, supporting independent discharging control. Controller 200 realizes global monitoring and dynamic scheduling. The number of charging modules = the number of discharging modules = the number of batteries (N), suitable for high-voltage series battery packs (e.g., N=16, total voltage ~60V).

[0046] The controller is also configured to control the discharge module to disconnect when the load fault is detected.

[0047] Understandably, the controller needs to achieve accurate fault diagnosis through multi-parameter fusion detection, detecting abnormal current, such as instantaneous overcurrent and continuous overload; abnormal voltage, such as output overvoltage / undervoltage; and detecting communication interruption. When the controller detects the above faults, it disconnects the discharge module to ensure the safety of the system.

[0048] In this embodiment, the charging module can be disconnected when the battery is fully charged or the load is uncontrolled, so as to ensure that the system will not cause safety risks due to overcharging. When it is necessary to switch to discharging immediately, the discharge module can directly output discharge, which ensures safety and does not cause the system to crash.

[0049] like Figure 3 As shown, Figure 3 A circuit diagram of the second embodiment of the high-voltage energy storage battery system protection circuit provided by this utility model.

[0050] Based on the first embodiment described above, a second embodiment of the protection circuit for the high-voltage energy storage battery system of this utility model is proposed.

[0051] The circuit further includes a protection module and a current shunt module; the protection module is connected to the peripheral interface, the charging module, the discharging module and the battery, and the current shunt module is connected to the peripheral interface and the battery; the protection module is used to disconnect the connection between the battery and the peripheral port when an overcurrent is detected; the current shunt module is used to control the charging current of the charging module.

[0052] It should be noted that the protection module provides dual safety protection with both a fuse and a circuit breaker, while the shunt module provides precise current control for the shunt. When the shunt detects that the current exceeds the circuit breaker threshold (e.g., 120% I_rated), the power conversion system (BMS) sends a trip signal to the circuit breaker to prematurely disconnect the circuit. If the circuit breaker fails, the current continues to rise to the fuse's blowing threshold (e.g., 500A), and the shunt may be damaged due to overheating, but the fuse will eventually trip. The shunt uses real-time current data to assist the BMS in adjusting charging parameters (e.g., voltage slope, cutoff current) to prevent charging interruptions caused by malfunctions of the protection module.

[0053] Understandably, fuses are used for battery cluster-level protection (such as 1500V / 2000A fuses) to prevent the propagation of short circuits between clusters. Circuit breakers are used for PCS (Power Conversion System) interface protection, supporting remote opening and closing operations. Shunts monitor the charging and discharging current of each battery cluster, working with the BMS to achieve inter-cluster balancing (e.g., current difference <5%). When the controller requires a fast response, the shunts suppress transient power fluctuations in the battery clusters by adjusting the charging current.

[0054] Specifically, the protection module (fuse + circuit breaker) is the last line of defense in a high-voltage energy storage system. Through a combination of irreversible melting and reusable mechanical disconnection, it provides comprehensive protection from transient surges to extreme short circuits. The shunt module (shunt) is a precision regulator in the charging process. Through high-precision current sampling and dynamic shunt, it achieves efficient and balanced charging and serves as a front-end monitoring node for the protection module. The collaborative operation of both in high-voltage scenarios constructs a complete technical system from fault prevention to safety isolation.

[0055] The discharge module includes: a first diode D1 and a first contactor C1; the anode of the first diode is connected to the positive terminal of the battery and the discharge module, the cathode of the first diode is connected to the first port of the first contactor and the discharge module, and the second port of the first contactor is connected to the positive terminal of the peripheral port and the discharge module.

[0056] Understandably, the discharge module, through the combined design of the first diode and the first contactor, achieves unidirectional conduction control, safety isolation, and high-reliability protection of the battery discharge path. The contactor mainly consists of an electromagnetic system, a contact system, an arc-extinguishing device, and other auxiliary components. The electromagnetic system comprises a coil, a stationary iron core, and a moving iron core (armature). When the coil is energized, the generated magnetic field magnetizes the stationary iron core and attracts the moving iron core, causing the contacts to move. The contact system includes main contacts and auxiliary contacts. The main contacts are used to connect or disconnect the main circuit, while the auxiliary contacts are used to control other components or for electrical interlocking. The arc-extinguishing device extinguishes the arc generated when the contacts break, preventing contact erosion. After the coil is energized, the electromagnetic attraction causes the moving iron core to close, closing the main contacts and connecting the circuit; after the coil is de-energized, the electromagnetic attraction disappears, the moving iron core resets under the action of the spring, the main contacts open, and the circuit is disconnected.

[0057] It should be noted that when the peripheral port is connected to a load, the current flows from the positive terminal of the battery through the first diode and the first contactor to the positive terminal of the peripheral port. When the load is abnormal, the controller controls the first contactor to disconnect to protect the circuit.

[0058] The charging module includes: a second diode D2 and a second contactor C2; the first end of the second contactor is connected to the anode of the first diode and the positive terminal of the battery, the second end of the second contactor is connected to the cathode of the first diode, the cathode of the second diode and the first end of the first contactor, and the anode of the second diode is connected to the second end of the first contactor and the positive terminal of the peripheral port.

[0059] Understandably, when the peripheral port is connected to the power supply, the current flows from the positive terminal of the power supply through the second diode and the second contactor to the positive terminal of the battery. When the power supply is abnormal or the battery is fully charged, the controller controls the second contactor to disconnect to protect the battery.

[0060] The protection module includes: a fuse, a first resistor R1, a third contactor C3, and a circuit breaker; one end of the fuse is connected to the positive terminal of the battery, and the other end of the fuse is connected to the anode of the first diode, the first terminal of the second contactor, and one end of the first resistor; the other end of the first resistor is connected to the first terminal of the third contactor; the second terminal of the third contactor is connected to the second terminal of the first contactor, the anode of the second diode, and the first input terminal of the circuit breaker; the first output terminal of the circuit breaker is connected to the second output terminal of the circuit breaker; the second input terminal of the circuit breaker is connected to the third input terminal of the circuit breaker; the third output terminal of the circuit breaker is connected to the positive terminal of the peripheral port; the fourth input terminal of the circuit breaker is connected to the shunt module; and the fourth output terminal of the circuit breaker is connected to the negative terminal of the peripheral port.

[0061] Understandably, as a one-time overcurrent protection device, a fuse permanently disconnects the circuit in the event of extreme overcurrent (such as a short circuit) through a melting mechanism, preventing thermal runaway or fire in the battery system. As a repeatable overcurrent / overvoltage protection device, a circuit breaker disconnects the circuit through mechanical contacts, supports manual or automatic reset, and is suitable for frequent plugging and unplugging of peripheral ports. The protection module employs a tiered protection strategy: primary protection (circuit breaker) handles low-to-medium level overcurrents, automatically attempting reclosing (e.g., 3 times) after triggering to avoid false tripping. Ultimate protection (fuse) only melts in the event of circuit breaker failure or an extreme fault (e.g., short-circuit current > 500A), ensuring system safety redundancy.

[0062] The current shunt module includes a current shunt and a fourth contactor C4; one end of the current shunt is connected to the negative terminal of the battery, the other end of the current shunt is connected to the first port of the fourth contactor, and the second port of the fourth contactor is connected to the fourth input terminal of the circuit breaker.

[0063] Understandably, as a low-resistance resistor, the shunt accurately calculates the current by measuring its own voltage drop (in the mV range) and can adjust the charging current distribution through parallel branches. The controller closes the fourth contactor C4, connecting the shunt to the main circuit and monitoring the current (such as battery discharge current and charging current) in real time. The shunt adjusts the discharge current and charging current.

[0064] Specifically, the controller's internal logic distinguishes between charging and discharging protection strategies. In single-cluster battery applications, when the battery reaches the charging protection threshold during charging (e.g., when there is overvoltage, overcurrent, or over / undertemperature protection for individual cells or the overall system), the controller can control the second contactor to disconnect. At this time, the external charging current and charging voltage are cut off through the diode. However, for the discharge circuit, it can ensure a stable output of discharge voltage and discharge current at the battery terminal.

[0065] In this embodiment, as Figure 3 As shown, a pair of common cathode diodes and a main contactor are added to the main circuit. The two contactors are connected to the common cathode diodes in an opposing manner. One contactor serves as a protection control device in the discharge mode, and the other serves as a protection control device in the charging mode. At this time, the control and protection of the charging and discharging circuit can be distinguished.

[0066] like Figure 4 As shown, Figure 4 A flowchart illustrating the third embodiment of the high-voltage energy storage battery system protection circuit provided by this utility model.

[0067] Based on the first and / or second embodiments described above, a third embodiment of the protection circuit for the high-voltage energy storage battery system of this utility model is proposed.

[0068] The controller is configured to request a preset voltage from the power source for charging, and reduce the charging current by a preset number of times to charge the battery with a preset current; the controller is also configured to eliminate the voltage difference between the high-voltage battery and the remaining battery by discharging equalization when the battery is charging with the preset current.

[0069] Understandably, the controller can protect the battery at the charging end by increasing the charging voltage of the battery system, reducing the charging current at the end, and extending the charging time during charging. During float charging, the controller's software logic makes judgments to periodically turn the first contactor off and on for end float charging. This, combined with the passive balancing circuit on the BMS in the module, optimizes the consistency of the battery cells.

[0070] In the Battery Management System (BMS), passive balancing circuitry is one of the core methods for optimizing cell consistency. It achieves dynamic voltage balance within the battery pack by consuming redundant energy from high-voltage cells. End-of-charge float charging (also known as intelligent float charging or intermittent float charging) is an advanced strategy in battery charging management. It refers to extending battery life, reducing energy waste, and improving safety by dynamically adjusting charging parameters (such as voltage, current, or the on / off state of the charging circuit) after the battery is close to full charge. The battery charging process typically consists of three stages: constant current charging (CC), which rapidly increases the battery voltage to 2.4V / cell (lead-acid batteries) with a fixed current (e.g., 0.1C); constant voltage charging (CV), which switches to a constant voltage mode (e.g., 2.4V / cell), with the current gradually decreasing to the float charging current threshold (e.g., C / 200). The float charging stage includes traditional float charging and end-of-charge float charging. Traditional float charging maintains a constant voltage (e.g., 2.25V / cell), with the current continuously decreasing to near zero, but the battery may remain in a slightly overcharged state for an extended period. End-of-charge float charging avoids overcharging by dynamically adjusting (e.g., intermittently shutting off the charging circuit) at the end of the float charging period (e.g., after the current decays to C / 200).

[0071] It should be noted that during the charging process, such as Figure 4 The flowchart control strategy continuously requests charging voltage at a preset voltage (high voltage) (e.g., 3.6V*NN, where NN is the number of battery cells). Then, through a multi-stage current reduction request control, the external charging device is repeatedly reduced in charging current, ensuring the battery is continuously charged at a preset current (low current) at the end, extending the charging time. This is combined with passive balancing (which requires increasing the voltage difference between individual cells to equalize the discharge of high-voltage cells and optimize battery consistency) to optimize battery performance. During charging, passive balancing is activated when the voltage of a single cell exceeds 3.4V and is 20mV higher than the lowest single cell voltage to optimize system consistency.

[0072] The controller is configured to reduce the charging current of the power supply and continue charging the remaining batteries when the charging module of one of the batteries is disconnected, until the remaining power of all batteries is greater than the preset power.

[0073] Understandably, in cascaded-stack-level multi-cluster battery systems, there is better calculation logic and control for calculating the remaining SOC of each battery in the system. At the end of charging, the lowest remaining SOC is reported, so that even the battery cluster with the lowest SOC can continue to be fully charged to 100%. At this point, the remaining SOC of all batteries in the system is 100%, and the end calibration of full charging has made the remaining SOC of all battery clusters consistent. In subsequent operation, will the remaining SOC of the entire system be unable to be calculated due to excessive differences in battery SOC?

[0074] It should be noted that in the cascading strategy of multi-cluster battery systems (stack-level systems), such as Figure 5 As shown, different clusters of batteries are controlled in stages at the end of the charging process. In a multi-cluster parallel high-voltage energy storage battery system, to ensure system-level safety redundancy and accurate global state assessment, the controller (BMS main control unit) adopts a conservative SOC aggregation strategy, that is, using the SOC value of the lowest remaining battery cluster in the system as the SOC reported by the stack level. When one cluster of batteries reaches full charge protection, its second contactor is disconnected through hierarchical control, and its remaining charge is calibrated to 100%, and it is removed from the system; then the stack level charging current is reduced (stack level charging current = lowest cluster requested charging current * P, where P is the number of online charging clusters) for continuous charging, and clusters that have reached the full charge threshold are gradually removed until the last cluster reaches full charge protection. At this point, all clusters can reach the full charge state, the charging capacity is saturated, and the remaining current SOC of the system stack level can reach 100%. The SOC can reach a relatively accurate state during the subsequent discharge process.

[0075] In this embodiment, in the cascaded-stacking system, when one cluster of batteries is fully charged, the charging can be stopped by disconnecting the second contactor, thereby ensuring that the other uncharged clusters can continue to charge, so that each cluster of batteries can reach a fully charged state and the charging capacity of all clusters of batteries can be maximized. This ensures that the capacity of the cascade system is sufficient during discharge, and more electricity can be released.

[0076] This utility model also proposes a battery system, which includes a high-voltage energy storage battery system protection circuit. The specific structure of the high-voltage energy storage battery system protection circuit is as described in the above embodiments. Since the battery system adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0077] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A protection circuit for a high-voltage energy storage battery system, characterized in that, The high-voltage energy storage battery system protection circuit includes: a controller, multiple charging modules, and multiple discharging modules; The controller connects to multiple charging modules and multiple discharging modules. The charging modules are connected to the battery and peripheral ports. The discharging modules are connected to the battery and peripheral ports. The discharging modules are connected in parallel with the charging modules. The number of charging modules and discharging modules is equal to the number of batteries. The peripheral ports are connected to a power source or a load. The charging module is used to control the power supply to charge the battery when the power is connected to the peripheral port; The controller is used to detect the remaining power of the battery, and when the remaining power is detected to be greater than a preset power, it controls the charging module connected to the battery to disconnect. The discharge module is used to control the battery to supply power to the load when the load is connected to the peripheral port.

2. The high-voltage energy storage battery system protection circuit as described in claim 1, characterized in that, The circuit also includes: a protection module and a current shunt module; The protection module is connected to the peripheral interface, the charging module, the discharging module and the battery, and the current shunt module is connected to the peripheral interface and the battery; The protection module is used to disconnect the connection between the battery and the peripheral port when an overcurrent is detected. The current shunt module is used to control the charging current of the charging module.

3. The high-voltage energy storage battery system protection circuit as described in claim 1, characterized in that, The controller is also configured to control the discharge module to disconnect when the load fault is detected.

4. The high-voltage energy storage battery system protection circuit as described in claim 1, characterized in that, The controller is configured to request a preset voltage from the power source for charging, and reduce the charging current by a preset number of times, so that the battery is charged with a preset current. The controller is also configured to eliminate the voltage difference between the high-voltage battery and the remaining battery by discharge equalization when the battery is charged with a preset current.

5. The high-voltage energy storage battery system protection circuit as described in claim 1, characterized in that, The controller is configured to reduce the charging current of the power supply and continue charging the remaining batteries when the charging module of one of the batteries is disconnected, until the remaining power of all batteries is greater than the preset power.

6. The high-voltage energy storage battery system protection circuit as described in claim 2, characterized in that, The discharge module includes: a first diode and a first contactor; The anode of the first diode is connected to the positive terminal of the battery and the discharge module, the cathode of the first diode is connected to the first port of the first contactor and the discharge module, and the second port of the first contactor is connected to the positive terminal of the peripheral port and the discharge module.

7. The high-voltage energy storage battery system protection circuit as described in claim 6, characterized in that, The charging module includes: a second diode and a second contactor; The first end of the second contactor is connected to the anode of the first diode and the positive terminal of the battery. The second end of the second contactor is connected to the cathode of the first diode, the cathode of the second diode, and the first end of the first contactor. The anode of the second diode is connected to the second end of the first contactor and the positive terminal of the peripheral port.

8. The high-voltage energy storage battery system protection circuit as described in claim 7, characterized in that, The protection module includes: a fuse, a first resistor, a third contactor, and a circuit breaker; One end of the fuse is connected to the positive terminal of the battery, and the other end of the fuse is connected to the anode of the first diode, the first terminal of the second contactor, and one end of the first resistor. The other end of the first resistor is connected to the first terminal of the third contactor. The second terminal of the third contactor is connected to the second terminal of the first contactor, the anode of the second diode, and the first input terminal of the circuit breaker. The first output terminal of the circuit breaker is connected to the second output terminal of the circuit breaker. The second input terminal of the circuit breaker is connected to the third input terminal of the circuit breaker. The third output terminal of the circuit breaker is connected to the positive terminal of the peripheral port. The fourth input terminal of the circuit breaker is connected to the shunt module, and the fourth output terminal of the circuit breaker is connected to the negative terminal of the peripheral port.

9. The high-voltage energy storage battery system protection circuit as described in claim 8, characterized in that, The current splitting module includes: a current splitter and a fourth contactor; One end of the shunt is connected to the negative terminal of the battery, and the other end of the shunt is connected to the first port of the fourth contactor. The second port of the fourth contactor is connected to the fourth input terminal of the circuit breaker.

10. A battery system, characterized in that, The battery system includes the high-voltage energy storage battery system protection circuit according to any one of claims 1-9.

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