Auxiliary power supply circuit and method for realizing energy storage battery balancing

Abstract

The present invention provides an auxiliary power supply circuit and method for realizing energy storage battery balancing, including a voltage stabilizing output module, a power supply regulating module and a control module; the input end of the voltage stabilizing output module is electrically connected to the voltage output end of the battery management chip, the first output end of the voltage stabilizing output module is electrically connected to the power supply end of the control module and the auxiliary power bus of the energy storage system at the same time, the second output end of the voltage stabilizing output module is electrically connected to the power supply input end of the power supply regulating module; the enable end of the power supply regulating module is electrically connected to the control output end of the battery management chip, the regulating output end of the power supply regulating module is electrically connected to the output voltage control end of the voltage stabilizing output module; the control signal output end of the control module is electrically connected to the power supply regulating module. The present invention improves the reliability of the auxiliary power supply while realizing active balancing at the battery module level.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to an auxiliary power supply circuit and method for realizing energy storage battery balancing. Background Art

[0002] The design of energy storage battery management system (BMS) based on hierarchical architecture generally includes battery cell management level (BMU or CSC), battery module management level (BCU or SBMU) and battery cluster management level (master control unit or MBMU). Regardless of which level of hardware circuit, auxiliary power supply is required to realize basic functions. The three-level BMS system generally requires an external 12V or 24V auxiliary power supply AC / DC (DC / DC) to be supplied to each level after conversion from the external power supply bus AC or DC. However, the existing design can only work when the AC or DC bus is established. In the scenario of completely off-grid operation or low external power supply reliability, the auxiliary power supply cannot be established or cannot be maintained stably, which will greatly limit the use of the energy storage system.

[0003] To solve this problem, most designs use an additional low-voltage power supply battery (UPS), but the low-voltage battery power outage cannot be avoided in weak grid or off-grid conditions, and the power supply reliability has not been improved. In addition, when the energy storage system is off-grid, the external auxiliary power supply for the battery management system comes from the AC or DC main output provided by the energy storage; the UPS is still required to provide auxiliary power to complete the main output power outage process.

[0004] In addition, the energy transfer methods commonly used in existing active balancing technologies include between two adjacent series-connected batteries, between a single battery and the battery module management level, between battery modules, or between a module and a battery cluster level. Although the balancing between two adjacent batteries can solve the balancing between series-connected cells in the same battery module, it cannot solve the inconsistency of the battery module, and the cost increase is more obvious; the principle of balancing a single battery and a battery module is the same, realizing the redistribution of differentiated battery cell energy to other cells in the module; the balancing between battery modules or between a module and a battery cluster has high power and high voltage, and requires high safety design of the balancing circuit. In order to achieve the balancing of all the cells in the battery cluster, the above methods require the superposition of multiple methods, which makes the active balancing function costly and restricts its application. Summary of the invention

[0005] The technical problem to be solved by the present invention is to propose an auxiliary power supply circuit and method for realizing energy storage battery balancing, realize safe power on and off when off-grid or without UPS, improve the reliability of auxiliary power supply and realize active balancing at battery module level.

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

[0007] An auxiliary power supply circuit for realizing energy storage battery balancing is used to be arranged in each battery module of the energy storage system in a one-to-one correspondence, wherein the battery module has at least two battery management chips, and the auxiliary power supply circuit includes a voltage stabilization output module, a power supply adjustment module and a control module;

[0008] The input end of the voltage-stabilizing output module is electrically connected to the voltage output end of the battery management chip, the first output end of the voltage-stabilizing output module is electrically connected to the power supply end of the control module and the auxiliary power bus of the energy storage system, and the second output end of the voltage-stabilizing output module is electrically connected to the power supply input end of the power supply adjustment module;

[0009] The enable terminal of the power supply regulating module is electrically connected to the control output terminal of the battery management chip, and the regulating output terminal of the power supply regulating module is electrically connected to the output voltage control terminal of the voltage stabilizing output module;

[0010] The control signal output terminal of the control module is electrically connected to the power supply adjustment module, and the control module is used to control the power supply adjustment module to adjust the output voltage of the first output terminal of the voltage-stabilizing output module.

[0011] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0012] An auxiliary power supply method for realizing energy storage battery balancing is applied to the above-mentioned auxiliary power supply circuit for realizing energy storage battery balancing, and comprises the following steps:

[0013] S1. When the energy storage system is powered on, the battery management chip of a battery module is awakened by communication;

[0014] S2, controlling the control output end of the battery management chip to enable the power supply regulation module, and controlling the voltage stabilization output module to output the auxiliary power supply voltage to the auxiliary power supply bus through the power supply regulation module, so that the auxiliary power supply bus supplies power to the BMS of all other battery modules and the BMS in the energy storage system;

[0015] S3. During the operation of the energy storage system, obtain and execute step 2 for the battery modules that need discharge equalization according to the balancing conditions of all battery modules;

[0016] S4. When the energy storage system needs to be powered off, the voltage stabilizing output module of the battery module with the current highest voltage is controlled to output the auxiliary power supply voltage to the auxiliary power bus to support the energy storage system to execute the power-off process;

[0017] S5. After the power-off process is completed, the power supply regulating module of the battery module with the highest voltage is controlled to turn off the output of the voltage stabilizing output module, and the battery management chips of all battery modules are controlled to enter a dormant state.

[0018] The beneficial effects of the present invention are as follows: an auxiliary power supply circuit and method for realizing energy storage battery balancing are provided, wherein an auxiliary power supply circuit composed of a voltage stabilizing output module, a power supply regulating module and a control module is arranged in each battery module, and when in use, the battery management chip of a battery module is awakened by communication to drive the corresponding power supply regulating module, so that the battery management chip outputs the auxiliary power supply voltage to the auxiliary power bus through the voltage stabilizing output module, and the auxiliary power bus supplies power to the BMS of all other battery modules and the BMS in the energy storage system, and during operation, the auxiliary power supply circuit is also used to allow other battery modules to participate in the power supply according to the discharge balancing requirements, thereby forming active balancing at the battery module level, balancing the balancing effect and cost, and reducing the reliability risk caused by the complexity of the multi-stage active balancing circuit, and then the battery module with the highest voltage maintains the power supply when power is turned off, until the energy storage system completes the power-off process, and then the whole system is shut down, so as to realize the self-starting and safe power-off of the BMS of the energy storage system in the absence of an AC or DC distribution network or a UPS without power. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A circuit connection diagram of an auxiliary power supply circuit for realizing energy storage battery balancing according to the present invention;

[0020] Figure 2 A circuit connection diagram of an isolated feedback module of an auxiliary power supply circuit for realizing energy storage battery balancing according to the present invention;

[0021] Figure 3 A schematic diagram of the steps of a method for supplying power to an auxiliary power source for achieving energy storage battery balancing according to the present invention;

[0022] Figure 4 The present invention is a flow chart of an auxiliary power supply method for realizing energy storage battery balancing.

[0023] Description of labels:

[0024] 1. Battery module; 2. Voltage stabilization output module; 3. Power supply regulation module; 4. Control module; 5. Isolation feedback module; 6. Communication adapter; 7. Auxiliary power bus; 8. Communication wake-up port;

[0025] 51. Operational amplifier circuit; 52. Optocoupler isolation circuit;

[0026] C1, first capacitor;

[0027] D1, first diode; D2, second diode; D3, third diode;

[0028] K1, first switch element; K2, second switch element;

[0029] L1, first inductor;

[0030] R1, first resistor;

[0031] T1, transformer;

[0032] U1, battery management chip; U2, driver chip; U3, power supply module; U4, main control chip. DETAILED DESCRIPTION

[0033] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.

[0034] Please refer to Figure 1 and Figure 2 , an auxiliary power supply circuit for realizing energy storage battery balancing, which is used to be arranged in each battery module 1 of the energy storage system in a one-to-one correspondence, wherein the battery module 1 has at least two battery management chips U1, and the auxiliary power supply circuit includes a voltage stabilization output module 2, a power supply adjustment module 3 and a control module 4;

[0035] The input end of the voltage-stabilizing output module 2 is electrically connected to the voltage output end of the battery management chip U1, the first output end of the voltage-stabilizing output module 2 is electrically connected to the power supply end of the control module 4 and the auxiliary power bus 7 of the energy storage system, and the second output end of the voltage-stabilizing output module 2 is electrically connected to the power supply input end of the power supply adjustment module 3;

[0036] The enabling end of the power supply regulating module 3 is electrically connected to the control output end of the battery management chip U1, and the regulating output end of the power supply regulating module 3 is electrically connected to the output voltage control end of the voltage stabilizing output module 2;

[0037] The control signal output end of the control module 4 is electrically connected to the power supply adjustment module 3 , and the control module 4 is used to control the power supply adjustment module 3 to adjust the output voltage of the first output end of the voltage stabilization output module 2 .

[0038] From the above description, it can be seen that the beneficial effects of the present invention are: providing an auxiliary power supply circuit for realizing energy storage battery balancing, wherein an auxiliary power supply circuit composed of a voltage stabilizing output module 2, a power supply regulating module 3 and a control module 4 is arranged in each battery module 1, and when the energy storage system needs to be started, the control output end of the battery management chip U1 enables the power supply regulating module 3, and the power supply regulating module 3 controls the voltage stabilizing output module 2 to output the auxiliary power supply voltage to the auxiliary power bus 7 through the output voltage control end of the voltage stabilizing output module 2, and the auxiliary power bus 7 supplies power to the BMS of all other battery modules 1 and the BMS in the energy storage system, so as to realize self-starting of the energy storage system, and can make other battery modules 1 participate in power supply with the help of the same auxiliary power supply circuit located in other battery modules 1, so as to realize active balancing of the battery modules 1, and when powering off, the battery module 1 maintains power supply until the power-off process is completed, so as to realize self-starting and safe power-off of the BMS of the energy storage system in the absence of an AC or DC distribution network or a UPS without power.

[0039] Furthermore, the power supply adjustment module 3 includes a driving chip U2, a first switch element K1, a second switch element K2 and a first resistor R1;

[0040] The power supply input terminal of the driving chip U2 is electrically connected to the second output terminal of the voltage-stabilizing output module 2, the enabling terminal of the driving chip U2 is electrically connected to the input terminal of the voltage-stabilizing output module 2 through the first switch K1, and the control terminal of the first switch K1 is electrically connected to the control output terminal of the battery management chip U1;

[0041] The output voltage control end of the voltage-stabilizing output module 2 is connected to one end of the first resistor R1 through the second switch K2, and the other end of the first resistor R1 is grounded;

[0042] The control end of the second switch element K2 is electrically connected to the current pin of the driving chip U2 , and the feedback pin of the driving chip U2 is electrically connected to the control signal output end of the control module 4 .

[0043] From the above description, it can be seen that the power supply regulation module 3 adopts the first switch element K1 to cooperate with the control output end of the battery management chip U1. The battery management chip U1 controls the first switch element K1 to be closed or open, thereby correspondingly controlling the opening and closing of the power supply regulation module 3, while the second switch element K2 participates in the adjustment process of the output voltage of the voltage stabilizing output module 2. The use of the switch element has a simple control logic and stable operation.

[0044] Furthermore, the voltage stabilizing output module 2 includes a transformer T1, a first diode D1, a second diode D2 and a third diode D3;

[0045] The first pin of the primary coil of the transformer T1 is electrically connected to the voltage output terminal of the battery management chip U1, the second pin of the primary coil of the transformer T1 is electrically connected to the regulation output terminal of the power supply regulation module 3, the first pin of the first secondary coil of the transformer T1 is electrically connected to the positive electrode of the first diode D1, the negative electrode of the first diode D1 is electrically connected to the positive electrode of the second diode D2, and the negative electrode of the second diode D2 is electrically connected to the power supply terminal of the control module 4 and the auxiliary power bus 7 of the energy storage system at the same time;

[0046] The cathode and anode of the third diode D3 are electrically connected to the first pin and the second pin of the first secondary coil of the transformer T1 respectively, and the second secondary coil of the transformer T1 is electrically connected to the power supply input terminal of the power supply adjustment module 3 .

[0047] From the above description, it can be seen that the voltage-stabilized output module 2 mainly uses the transformer T1 for voltage conversion, and is also provided with a diode and other anti-reverse current designs.

[0048] Furthermore, the voltage stabilization output module 2 further includes a first capacitor C1 and a first inductor L1;

[0049] Two ends of the first capacitor C1 are electrically connected to the first pin and the second pin of the first secondary coil of the transformer T1 respectively, and the cathode of the first diode D1 is electrically connected to the anode of the second diode D2 through the first inductor L1.

[0050] It can be seen from the above description that the first capacitor C1 and the first inductor L1 are introduced at the output side of the transformer T1 to filter the output signal.

[0051] Furthermore, the control module 4 includes a power supply module U3, a main control chip U4 and an isolation feedback module 5;

[0052] The first output end of the voltage-stabilizing output module 2 is electrically connected to the voltage input end of the main control chip U4 through the power supply module U3, and the first output end of the voltage-stabilizing output module 2 is electrically connected to the voltage input end of the isolation feedback module 5;

[0053] The control signal output terminal of the main control chip U4 is electrically connected to the power supply adjustment module 3 through the isolation feedback module 5 .

[0054] From the above description, it can be seen that the control module 4 sets an isolation feedback module 5 between the main control chip U4 and the power supply regulation module 3, and cooperates with the transformer T1 of the voltage stabilizing output module 2, so that the main control part and the battery management chip U1 are electrically isolated and belong to different circuit loops to avoid mutual interference.

[0055] Furthermore, the control signal output terminal of the main control chip U4 includes a positive feedback output terminal and a negative feedback output terminal;

[0056] The positive feedback output terminal and the negative feedback output terminal are electrically connected to the first input terminal and the second input terminal of the isolation feedback module 5 respectively, and the output terminal of the isolation feedback module 5 is electrically connected to the power supply regulation module 3. The isolation feedback module 5 is used to output a corresponding feedback signal to the power supply regulation module 3 according to the voltage regulation signal of the positive feedback output terminal or the voltage regulation signal of the negative feedback output terminal.

[0057] From the above description, it can be seen that in the feedback adjustment part, the output of the main control chip U4 is divided into a positive feedback output terminal and a negative feedback output terminal. Combined with the isolation feedback module 5, the corresponding control signal is obtained to the power supply adjustment module 3, thereby realizing flexible adjustment of the output constant voltage size of the voltage stabilizing output module 2.

[0058] Furthermore, the isolation feedback module 5 includes an operational amplifier circuit 51 and an optical coupling isolation circuit 52;

[0059] The control signal output end of the main control chip U4 is connected to the input end of the operational amplifier circuit 51 , the output end of the operational amplifier circuit 51 is connected to the input end of the optocoupler isolation circuit 52 , and the output end of the optocoupler isolation circuit 52 is electrically connected to the power supply adjustment module 3 .

[0060] From the above description, it can be seen that the isolated feedback module 5 includes an operational amplifier circuit 51 and an optical coupler isolation circuit 52. The operational amplifier circuit 51 amplifies the signal to a desired amplitude, while the optical coupler isolation circuit 52 is used to achieve electrical isolation between the front and rear stages to reduce signal interference.

[0061] Furthermore, it also includes a communication adapter 6, and the communication adapter 6 is communicatively connected to the battery management chip U1.

[0062] From the above description, it can be seen that the communication adapter 6 is used to communicate and wake up the battery management chip U1, and the communication method can be preset, which is convenient to use.

[0063] Please refer to Figure 3 and Figure 4 , an auxiliary power supply method for realizing energy storage battery balancing, applied to the above-mentioned auxiliary power supply circuit for realizing energy storage battery balancing, comprising the following steps:

[0064] S1. When the energy storage system is powered on, the battery management chip U1 of a battery module 1 is awakened by communication;

[0065] S2, controlling the control output end of the battery management chip U1 to enable the power supply regulation module 3, and controlling the voltage stabilization output module 2 to output the auxiliary power supply voltage to the auxiliary power supply bus 7 through the power supply regulation module 3, so that the auxiliary power supply bus 7 supplies power to the BMS of all other battery modules 1 and the BMS in the energy storage system;

[0066] S3, during the operation of the energy storage system, obtaining and executing step S2 for the battery modules 1 that need discharge equalization according to the equalization status of all battery modules 1;

[0067] S4, when the energy storage system needs to be powered off, the voltage stabilizing output module 2 of the battery module 1 with the current highest voltage is controlled to output the auxiliary power supply voltage to the auxiliary power bus 7 to support the energy storage system to execute the power-off process;

[0068] S5. After the power-off process is completed, the power supply regulating module 3 of the battery module 1 with the highest voltage is controlled to turn off the output of the voltage stabilizing output module 2, and the battery management chip U1 of all the battery modules 1 is controlled to enter a dormant state.

[0069] From the above description, it can be seen that the beneficial effect of the present invention is to provide an auxiliary power supply method for realizing energy storage battery balancing, and an auxiliary power supply circuit composed of a voltage stabilizing output module 2, a power supply regulating module 3 and a control module 4 is arranged in each battery module 1. When in use, the battery management chip U1 of a battery module 1 is awakened by communication to drive the corresponding power supply regulating module 3, so that the battery management chip U1 outputs the auxiliary power supply voltage to the auxiliary power bus 7 through the voltage stabilizing output module 2, and the auxiliary power bus 7 supplies power to the BMS of all other battery modules 1 and the BMS in the energy storage system, and during operation, the auxiliary power supply circuit is also used to allow other battery modules 1 to participate in power supply according to the discharge balancing requirements, so as to constitute a level 1 active balancing of the battery module, balance the balancing effect and cost, and reduce the reliability risk caused by the complexity of the multi-level active balancing circuit, and then the battery module 1 with the highest voltage maintains power supply when power is turned off, until the energy storage system completes the power-off process, and executes the whole system shutdown, in the absence of AC or DC distribution network, or UPS power-off conditions, the BMS of the energy storage system is self-started and safely powered off.

[0070] Furthermore, the step S1 specifically includes:

[0071] The communication adapter 6 is controlled to communicate and wake up a battery management chip U1 of the battery module 1, so that the awakened battery management chip U1 wakes up the remaining battery management chips U1.

[0072] From the above description, it can be known that the communication adapter 6 is controlled to communicate and wake up a battery management chip U1 of the battery module 1, and the awakened battery management chip U1 wakes up the remaining battery management chips U1, thereby realizing isolated communication and reducing the workload of the communication adapter 6.

[0073] Please refer to Figure 1 , Embodiment 1 of the present invention is:

[0074] An auxiliary power supply circuit for realizing energy storage battery balancing is used to be arranged in each battery module 1 of the energy storage system in a one-to-one correspondence. Each module contains an internal auxiliary power supply that meets the power supply power related to the BMS safety function. The auxiliary power supplies of all M battery modules 1 together with the external power supply constitute M+1 level redundancy, which greatly improves the reliability of the auxiliary power supply. Before introducing the circuit composition of this embodiment, it should be noted that:

[0075] For the usual energy storage battery design, each series-connected battery module 1 contains a BMU circuit board consisting of 1 MCU (microcontroller) and N battery management chips U1 (AFE), and all batteries contain M battery modules 1, that is, M BMU circuit boards; under working conditions, the control circuit of the entire energy storage system is powered by an external auxiliary power supply AC / DC (DC / DC).

[0076] Reference Figure 1 As shown, the auxiliary power supply circuit of this embodiment includes a voltage stabilizing output module 2, a power supply regulating module 3 and a control module 4; the input end of the voltage stabilizing output module 2 is electrically connected to the voltage output end of the battery management chip U1, the first output end of the voltage stabilizing output module 2 is electrically connected to the power supply end of the control module 4 and the auxiliary power bus 7 of the energy storage system at the same time, and the second output end of the voltage stabilizing output module 2 is electrically connected to the power supply input end of the power supply regulating module 3; the enable end of the power supply regulating module 3 is electrically connected to the control output end of the battery management chip U1, and the regulating output end of the power supply regulating module 3 is electrically connected to the output voltage control end of the voltage stabilizing output module 2; the control signal output end of the control module 4 is electrically connected to the power supply regulating module 3, and the control module 4 is used to control the power supply regulating module 3 to adjust the output voltage of the first output end of the voltage stabilizing output module 2. In addition, this embodiment is equipped with a communication adapter 6, which is connected to the battery management chip U1 for waking up the battery management chip U1.

[0077] Combination Figure 1 It can be seen that the voltage output end of the battery management chip U1 is not only used to provide input voltage to the voltage stabilizing output module 2, but also provides an enable voltage to the enable end of the power supply regulating module 3. Whether the enable voltage can reach the power supply regulating module 3 is controlled by the control output end of the battery management chip U1.

[0078] In the output part of the voltage-stabilized output module 2, when the voltage-stabilized output module 2 has a voltage output, such as outputting an auxiliary power supply voltage, the output auxiliary power supply voltage is moved to the connected auxiliary power supply bus 7; the auxiliary power supply bus 7 is used to power all other battery modules 1 of the BMS powered by the auxiliary power supply and the BMS of the energy storage system powered by the auxiliary power supply; therefore, the auxiliary power supply circuit of a battery module 1 supplies power to the auxiliary power supply bus 7, so that other BMSs are powered on and the energy storage system is self-started.

[0079] At the same time, the control module 4 is also powered and started. The control module 4 is used to control the power supply adjustment module 3 to adjust the voltage of the voltage-stabilized output module 2 to meet actual needs; for example: for some battery modules 1 with higher voltages, it can respond to start the auxiliary power supply circuit inside it to enable it to participate in the power supply.

[0080] In this embodiment, the power supply adjustment module 3 includes a driver chip U2, a first switch K1, a second switch K2 and a first resistor R1; the power supply input terminal of the driver chip U2 is electrically connected to the second output terminal of the voltage stabilizing output module 2, the enable terminal of the driver chip U2 is electrically connected to the input terminal of the voltage stabilizing output module 2 through the first switch K1, and the control terminal of the first switch K1 is electrically connected to the control output terminal of the battery management chip U1; the output voltage control terminal of the voltage stabilizing output module 2 is connected to one end of the first resistor R1 through the second switch K2, and the other end of the first resistor R1 is grounded; the control terminal of the second switch K2 is electrically connected to the current pin of the driver chip U2, and the feedback pin of the driver chip U2 is electrically connected to the control signal output terminal of the control module 4. Among them, the first switch K1 and the second switch K2 can be selected as MOS tube lamp switch devices.

[0081] In this embodiment, the voltage stabilizing output module 2 includes a transformer T1, a first capacitor C1, a first inductor L1, a first diode D1, a second diode D2 and a third diode D3; the first pin of the primary coil of the transformer T1 is electrically connected to the voltage output terminal of the battery management chip U1, the second pin of the primary coil of the transformer T1 is electrically connected to the regulation output terminal of the power supply regulation module 3, the first pin of the first secondary coil of the transformer T1 is electrically connected to the positive electrode of the first diode D1, the negative electrode of the first diode D1 is electrically connected to the positive electrode of the second diode D2, and the negative electrode of the second diode D2 is electrically connected to the power supply terminal of the control module 4 and the auxiliary power bus 7 of the energy storage system at the same time; the negative electrode and the positive electrode of the third diode D3 are electrically connected to the first pin of the first secondary coil and the second pin of the first secondary coil of the transformer T1 respectively, and the second secondary coil of the transformer T1 is electrically connected to the power supply input terminal of the power supply regulation module 3. The two ends of the first capacitor C1 are electrically connected to the first pin of the first secondary coil of the transformer T1 and the second pin of the first secondary coil respectively, and the negative electrode of the first diode D1 is electrically connected to the positive electrode of the second diode D2 through the first inductor L1.

[0082] Please refer to Figure 2 , Embodiment 2 of the present invention is:

[0083] An auxiliary power supply circuit for realizing energy storage battery balancing. On the basis of the above-mentioned embodiment one, the control module 4 includes a power supply module U3, a main control chip U4 and an isolation feedback module 5; the first output end of the voltage stabilizing output module 2 is electrically connected to the voltage input end of the main control chip U4 through the power supply module U3, and the first output end of the voltage stabilizing output module 2 is electrically connected to the voltage input end of the isolation feedback module 5; the control signal output end of the main control chip U4 is electrically connected to the power supply adjustment module 3 through the isolation feedback module 5.

[0084] In this embodiment, the control signal output end of the main control chip U4 includes a positive feedback output end and a negative feedback output end; the positive feedback output end and the negative feedback output end are electrically connected to the first input end and the second input end of the isolation feedback module 5 respectively, and the output end of the isolation feedback module 5 is electrically connected to the power supply regulation module 3, and the isolation feedback module 5 is used to output a corresponding feedback signal to the power supply regulation module 3 according to the voltage regulation signal of the positive feedback output end or the voltage regulation signal of the negative feedback output end.

[0085] In this embodiment, the isolation feedback module 5 includes an operational amplifier circuit 51 and an optocoupler isolation circuit 52; the control signal output end of the main control chip U4 is connected to the input end of the operational amplifier circuit 51, the output end of the operational amplifier circuit 51 is connected to the input end of the optocoupler isolation circuit 52, and the output end of the optocoupler isolation circuit 52 is electrically connected to the power supply adjustment module 3.

[0086] Please refer to Figure 1 , Figure 3 as well as Figure 4 , Embodiment 3 of the present invention is:

[0087] An auxiliary power supply method for realizing energy storage battery balancing is applied to an auxiliary power supply circuit for realizing energy storage battery balancing in Embodiment 1 or 2, and comprises the following steps:

[0088] S1. When the energy storage system is powered on, the battery management chip U1 of a battery module 1 is awakened by communication;

[0089] In this embodiment, if Figure 1 As shown, the communication adapter 6 is controlled to communicate and wake up a battery management chip U1 of the battery module 1, such as K_AFE_1, so that the awakened battery management chip U1 wakes up the remaining battery management chips U1. In addition, each battery module 1 is provided with a communication wake-up port 8, and a communication method can be preset on the communication wake-up port 8 to wake up the battery management chip U1.

[0090] At the same time, in order to facilitate the implementation of subsequent active balancing of the battery modules 1, the battery module 1 used for powering up the system is preferably the battery module 1 with the highest voltage.

[0091] S2, control the control output end of the battery management chip U1 to enable the power supply regulation module 3, and control the voltage stabilization output module 2 to output the auxiliary power supply voltage to the auxiliary power bus 7 through the power supply regulation module 3, so that the auxiliary power bus 7 supplies power to the BMS of all other battery modules 1 and the BMS in the energy storage system;

[0092] In this embodiment, if Figure 1 As shown, the auxiliary power supply circuit, the battery management chip U1, and the energy storage battery are considered as a set of internal auxiliary power supplies, which can output a rated voltage of and an output voltage ranging from , and accept the control of AFE and MCU to start / shut down and adjust the output voltage. The specific process is as follows:

[0093] On the one hand, according to the preset communication instruction, the control output end of the battery management chip U1, that is, the I / O port named "AUX_ON" in the figure, outputs a control signal to the first switch element K1, causing the first switch element K1 to be turned on, so that the voltage output of the battery management chip U1 is connected to the enable end of the driver chip U2, and the driver chip U2 is started; and in the initial state, the driver chip U2 controls the voltage stabilizing output module 2 to output the rated voltage, which is transmitted to the auxiliary power bus 7 through the auxiliary power port, so that the auxiliary power bus 7 supplies power to the BMS of all other battery modules 1 and the BMS in the energy storage system.

[0094] At the same time, the output of the voltage stabilizing output module 2 also supplies power to the main control chip U4 through the power supply module U3, and supplies power to the isolation feedback module 5 through the secondary second coil, so that the feedback control part is started.

[0095] On the other hand, the feedback control part is controlled by the main control chip U4 through the isolation feedback module 5 to control the power supply adjustment module 3, which specifically includes:

[0096] The main control chip U4 outputs control signals PWM1 and PWM2 through two PWM ports, namely the positive feedback output terminal "AUX_UP" and the negative feedback output terminal "AUX_DOWN", and adjusts the driver chip U2 through the path of the isolated feedback circuit to achieve control The amplitude of .

[0097] Through circuit design, Voltage is the same as the duty cycle of the output PWM1 signal Inversely proportional, Voltage Inversely proportional, and satisfies the following formula (1):

[0098] (1)

[0099] When powered on, the output PWM1 signal of a battery module 1 is 0, then ; After that, the auxiliary power bus 7 starts the energy storage system, the DC power bus or AC power bus outputs, and the DC / DC or AC / DC external auxiliary power supply is started; and when all battery modules 1 and the BMS equipment powered by the auxiliary power supply in the energy storage system are switched to the external auxiliary power supply, it is determined that the external auxiliary power supply has been started, and the PWM1 signal is output, It starts from 0 and increases slowly, passing through the path of the isolated feedback module 5, and adjusts the drive circuit pin (Feedback end) The size of the signal slowly decreases The output is kept until it reaches 0. At this point, the enabled battery module is turned off, specifically by sending a communication instruction to the battery management chip U1 to turn off the I / O port output signal "AUX_ON" to power off the drive circuit. During the control of PWM1, the output of PWM2 is always 0.

[0100] In contrast to the above, through circuit design, The duty cycle of the PWM2 signal output is the same as Proportional, same is proportional to and satisfies formula (2):

[0101] (2)

[0102] S3. During the operation of the energy storage system, obtain and execute step S2 for the battery modules that need discharge equalization according to the balancing conditions of all battery modules;

[0103] In this embodiment, the battery module management level or the battery cluster management level determines the balancing conditions of all battery modules. For example, if the battery module needs to be discharged and balanced, the voltage of its internal auxiliary power supply is started and slowly increased to enable it to participate in the power supply, so that the energy of some modules is transferred to the auxiliary power bus. The specific process includes:

[0104] For the battery modules that need discharge balancing, execute step 2, that is, for the main control chip of the unused battery modules, repeat the above process of outputting PWM1. In the active balancing process, when the output voltage of the battery module needs to be adjusted, Slowly reduce the PWM1 duty cycle, while Slowly increase the PWM2 duty cycle to make Slowly increase the voltage to , so that energy is transferred from the module to the auxiliary power bus 7. When it is detected that balancing is not required, the opposite is true. Slowly increase the PWM1 duty cycle and Slowly reduce the PWM2 duty cycle to make The voltage slowly drops to 0, and then through the communication instruction to the battery management chip U1, its I / O port output signal "AUX_ON" is turned off to power off the drive circuit.

[0105] S4, when the energy storage system needs to be powered off, the voltage stabilizing output module 2 of the battery module 1 with the current highest voltage is controlled to output the auxiliary power supply voltage to the auxiliary power bus 7 to support the energy storage system to execute the power-off process;

[0106] In this embodiment, when an off-grid shutdown command is received, the battery module 1 management level or the battery cluster management level determines the battery module 1 with the highest current voltage, and also uses the above-mentioned output control process of the voltage stabilizing output module 2 to control the voltage stabilizing output module 2 of the battery module 1 with the highest current voltage to output the auxiliary power supply voltage to the auxiliary power bus 7.

[0107] S5. After the power-off process is completed, the power supply regulating module 3 of the battery module 1 with the highest voltage is controlled to turn off the output of the voltage stabilizing output module 2, and the battery management chip U1 of all the battery modules 1 is controlled to enter a dormant state.

[0108] In summary, the present invention provides an auxiliary power supply circuit and method for realizing energy storage battery balancing. An auxiliary power supply circuit composed of a voltage stabilizing output module, a power supply regulating module and a control module is arranged in each battery module. When in use, the battery management chip of a battery module is awakened by communication to drive the corresponding power supply regulating module, so that the battery management chip outputs the auxiliary power supply voltage to the auxiliary power bus through the voltage stabilizing output module, and the auxiliary power bus supplies power to the BMS of all other battery modules and the BMS in the energy storage system. In the operation process, the auxiliary power supply circuit is also used to allow other battery modules to participate in the power supply according to the discharge balancing requirements. Active balancing at the battery module level balances the balancing effect and cost, reduces the reliability risk brought by the complexity of multi-level active balancing circuits, and then the battery module with the highest voltage maintains power supply when power is cut off until the energy storage system completes the power-off process, and then executes a full system shutdown. In the absence of AC or DC distribution networks, or UPS power outage, the BMS self-start and safe power-off of the energy storage system can be achieved, reducing the replacement and maintenance required due to the short life of UPS and other equipment, reducing the system's full life cycle cost. At the same time, the preset communication startup mode can be set through portable communication adapters such as laptops, which also improves the safety of starting the off-grid energy storage system and avoids false triggering.

[0109] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An auxiliary power supply circuit for realizing energy storage battery balancing, which is used to be arranged in each battery module of an energy storage system in a one-to-one correspondence, wherein the battery module has at least two battery management chips, characterized in that: It includes a voltage stabilizing output module, a power supply regulating module and a control module; The input end of the voltage-stabilizing output module is electrically connected to the voltage output end of the battery management chip, the first output end of the voltage-stabilizing output module is electrically connected to the power supply end of the control module and the auxiliary power bus of the energy storage system, and the second output end of the voltage-stabilizing output module is electrically connected to the power supply input end of the power supply adjustment module; The enable terminal of the power supply regulating module is electrically connected to the control output terminal of the battery management chip, and the regulating output terminal of the power supply regulating module is electrically connected to the output voltage control terminal of the voltage stabilizing output module; The control signal output end of the control module is electrically connected to the power supply adjustment module, and the control module is used to control the power supply adjustment module to adjust the output voltage of the first output end of the voltage stabilization output module; The power supply adjustment module includes a driving chip, a first switch component, a second switch component and a first resistor; The power supply input terminal of the driving chip is electrically connected to the second output terminal of the voltage stabilizing output module, the enable terminal of the driving chip is electrically connected to the input terminal of the voltage stabilizing output module through the first switch component, and the control terminal of the first switch component is electrically connected to the control output terminal of the battery management chip; The output voltage control terminal of the voltage-stabilizing output module is connected to one end of the first resistor through the second switch, and the other end of the first resistor is grounded; The control terminal of the second switch element is electrically connected to the current pin of the driving chip, and the feedback pin of the driving chip is electrically connected to the control signal output terminal of the control module.

2. The auxiliary power supply circuit for realizing energy storage battery balancing according to claim 1, characterized in that: The voltage stabilizing output module includes a transformer, a first diode, a second diode and a third diode; The first pin of the primary coil of the transformer is electrically connected to the voltage output terminal of the battery management chip, the second pin of the primary coil of the transformer is electrically connected to the regulation output terminal of the power supply regulation module, the first pin of the first secondary coil of the transformer is electrically connected to the positive electrode of the first diode, the negative electrode of the first diode is electrically connected to the positive electrode of the second diode, and the negative electrode of the second diode is electrically connected to the power supply terminal of the control module and the auxiliary power bus of the energy storage system at the same time; The cathode and anode of the third diode are electrically connected to the first pin and the second pin of the first secondary coil of the transformer respectively, and the second secondary coil of the transformer is electrically connected to the power supply input terminal of the power supply adjustment module.

3. The auxiliary power supply circuit for realizing energy storage battery balancing according to claim 2, characterized in that: The voltage stabilization output module further includes a first capacitor and a first inductor; Two ends of the first capacitor are electrically connected to a first pin of a first secondary coil and a second pin of a first secondary coil of the transformer respectively, and a cathode of the first diode is electrically connected to an anode of the second diode through the first inductor.

4. The auxiliary power supply circuit for realizing energy storage battery balancing according to claim 1, characterized in that: The control module includes a power supply module, a main control chip and an isolation feedback module; The first output end of the voltage-stabilizing output module is electrically connected to the voltage input end of the main control chip through the power supply module, and the first output end of the voltage-stabilizing output module is electrically connected to the voltage input end of the isolation feedback module; The control signal output terminal of the main control chip is electrically connected to the power supply adjustment module through the isolation feedback module.

5. The auxiliary power supply circuit for realizing energy storage battery balancing according to claim 4, characterized in that: The control signal output terminal of the main control chip includes a positive feedback output terminal and a negative feedback output terminal; The positive feedback output terminal and the negative feedback output terminal are electrically connected to the first input terminal and the second input terminal of the isolation feedback module respectively, and the output terminal of the isolation feedback module is electrically connected to the power supply regulation module. The isolation feedback module is used to output a corresponding feedback signal to the power supply regulation module according to the voltage regulation signal of the positive feedback output terminal or the voltage regulation signal of the negative feedback output terminal.

6. The auxiliary power supply circuit for realizing energy storage battery balancing according to claim 4, characterized in that: The isolated feedback module includes an operational amplifier circuit and an optocoupler isolation circuit; The control signal output end of the main control chip is connected to the input end of the operational amplifier circuit, the output end of the operational amplifier circuit is connected to the input end of the optocoupler isolation circuit, and the output end of the optocoupler isolation circuit is electrically connected to the power supply adjustment module.

7. The auxiliary power supply circuit for realizing energy storage battery balancing according to claim 1, characterized in that: It also includes a communication adapter, which is communicatively connected to the battery management chip.

8. An auxiliary power supply method for realizing energy storage battery balancing, applied to an auxiliary power supply circuit for realizing energy storage battery balancing according to any one of claims 1 to 7, characterized in that: The steps include: S1. When the energy storage system is powered on, the battery management chip of a battery module is awakened by communication; S2, controlling the control output end of the battery management chip to enable the power supply regulation module, and controlling the voltage stabilization output module to output the auxiliary power supply voltage to the auxiliary power supply bus through the power supply regulation module, so that the auxiliary power supply bus supplies power to the BMS of all other battery modules and the BMS in the energy storage system; S3, during the operation of the energy storage system, obtaining and executing step S2 for the battery modules that need discharge equalization according to the balancing conditions of all battery modules; S4. When the energy storage system needs to be powered off, the voltage stabilizing output module of the battery module with the current highest voltage is controlled to output the auxiliary power supply voltage to the auxiliary power bus to support the energy storage system to execute the power-off process; S5. After the power-off process is completed, the power supply regulating module of the battery module with the highest voltage is controlled to turn off the output of the voltage stabilizing output module, and the battery management chips of all battery modules are controlled to enter a dormant state.

9. The auxiliary power supply method for realizing energy storage battery balancing according to claim 8, characterized in that: The step S1 specifically includes: The communication adapter is controlled to communicate and wake up a battery management chip of the battery module, so that the awakened battery management chip wakes up the remaining battery management chips.

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