A weak current intelligent control circuit for a battery management system

Abstract

This invention discloses a low-voltage intelligent control circuit for a battery management system, relating to the field of battery management technology. It includes a microcontroller module that receives voltage state detected by a voltage detection module. Based on the relationship and difference between the detected signal and the average battery voltage, it controls an auxiliary management module to store the electrical energy released by a first, second, or third battery module. The auxiliary module also performs charging compensation control on the first, second, or third battery module to achieve battery voltage equalization control. Simultaneously, during discharge, it disconnects battery modules with large voltage differences from the average battery voltage and controls the auxiliary management module to perform series compensation power supply control on the disconnected first, second, or third battery modules. This invention's low-voltage intelligent control circuit for the battery management system avoids increasing the discharge rate, ensuring battery safety while meeting discharge requirements and improving battery discharge efficiency.

Description

Technical Field

[0001] This invention relates to the field of battery management technology, specifically a low-voltage intelligent control circuit for a battery management system. Background Technology

[0002] The battery management system (BMS) is a core system used to monitor, control, and manage battery packs (such as lithium-ion batteries and lead-acid batteries). Specifically, when controlling the charging and discharging of the battery, it transfers electrical energy from the high-voltage battery to the low-voltage battery to achieve voltage equalization. However, when the battery is discharging, it accelerates the discharge rate of the high-voltage battery to shorten the time required for battery equalization. When there is a large difference between the voltage of the high-voltage battery and the average battery voltage, it will increase the discharge rate of the high-voltage battery, thereby reducing the battery's range. Furthermore, to ensure battery safety, the BMS may control the battery to stop discharging, reducing the battery's discharge efficiency. Therefore, improvements are needed. Summary of the Invention

[0003] This invention provides a low-voltage intelligent control circuit for a battery management system to solve the problems mentioned in the background art.

[0004] According to an embodiment of the present invention, a low-voltage intelligent control circuit for a battery management system is provided, comprising:

[0005] The charging and discharging module is connected to the first battery module and the auxiliary management module, and is used to receive DC power and perform charging control or receive power output from the first battery module or the auxiliary management module and perform discharging control.

[0006] The first battery module is used to receive DC power and store and discharge it.

[0007] The second battery module is connected to the first battery module and is used to store energy and discharge energy in series with the first battery module.

[0008] The third battery module is connected to the second battery module and is used to store energy and discharge energy in series with the second battery module.

[0009] A voltage detection module is connected to the first battery module, the second battery module, and the third battery module, and is used to detect the voltage of the first battery module, the second battery module, and the third battery module and output a first voltage signal, a second voltage signal, and a third voltage signal respectively.

[0010] The microcontroller module, connected to the voltage detection module, the first battery module, the second battery module, the third battery module, and the auxiliary management module, receives the first voltage signal, the second voltage signal, and the third voltage signal; compares the voltage of the first voltage signal, the second voltage signal, and the third voltage signal with the average battery voltage; and controls the auxiliary management module to perform energy storage and independent discharge. During discharge, when the first voltage signal is less than the second voltage signal and the third voltage signal, and the difference between the first voltage signal and the average battery voltage is less than a set difference threshold, the microcontroller module is controlled to disconnect and the auxiliary management module is controlled to perform series compensation power supply. When the second voltage signal is less than the first voltage signal and the third voltage signal, and the difference between the second voltage signal and the average battery voltage is less than the difference threshold, the microcontroller module is controlled to disconnect and the auxiliary management module is controlled to perform series compensation power supply. When the third voltage signal is less than the second voltage signal and the first voltage signal, and the difference between the third voltage signal and the average battery voltage is less than a set difference threshold, the microcontroller module is controlled to disconnect and the auxiliary management module is controlled to perform series compensation power supply.

[0011] The auxiliary management module, connected to the first, second, and third battery modules, is used to store DC power and release the stored power. During charging, discharging, or resting, it controls the discharge of the first, second, or third battery modules with voltages higher than the average battery voltage, releases the stored power, and provides charging compensation for the first, second, and third battery modules connected in series. During discharging, it replaces the first, second, or third battery modules in an open-circuit state to provide series compensation power.

[0012] As a further embodiment of the present invention: the charging and discharging module includes a charging and discharging control device and a first capacitor; the first battery module includes a first thyristor, a first inverter and a first battery; the second battery module includes a second thyristor, a second inverter and a second battery; the third battery module includes a third thyristor, a third battery and a third inverter; the microcontroller module includes a first controller;

[0013] Preferably, the first terminal of the charge / discharge control device is connected to the first terminal of the first thyristor and connected to the second terminal of the charge / discharge control device and the second terminal of the third battery through the first capacitor. The second terminal of the first thyristor is connected to the first terminal of the first battery. The second terminal of the first battery is connected to one terminal of the second thyristor. The other terminal of the second thyristor is connected to the first terminal of the second battery. The second terminal of the second battery is connected to one terminal of the third thyristor. The other terminal of the third thyristor is connected to the first terminal of the third battery. The control terminals of the first thyristor, the second thyristor, and the third thyristor are respectively connected to the output terminals of the first inverter, the second inverter, and the third inverter. The input terminals of the first inverter, the second inverter, and the third inverter are respectively connected to the IO1, IO2, and IO3 terminals of the first controller.

[0014] As a further embodiment of the present invention: the auxiliary management module includes a first diode, a second diode, a first power transistor, a third diode, and a first inductor;

[0015] Preferably, the anode of the first diode is connected to the first terminal of the first thyristor, the cathode of the first diode is connected to the cathode of the second diode and connected to the drain of the first power transistor and the anode of the third diode through the first inductor, the source of the first power transistor is connected to the second terminal of the first battery, and the gate of the first power transistor is connected to the IO4 terminal of the first controller.

[0016] As a further embodiment of the present invention: the auxiliary management module further includes a third power transistor, a fourth power transistor, a second inductor, a fifth power transistor, and a sixth power transistor;

[0017] Preferably, the source of the third power transistor is connected to the source of the first power transistor, the source of the fourth power transistor is connected to the anode of the second diode, the drain of the third power transistor is connected to the drain of the fourth power transistor and connected to the drain of the fifth power transistor and the source of the sixth power transistor through the second inductor, the drain of the sixth power transistor is connected to the cathode of the third diode, the source of the fifth power transistor is connected to the second terminal of the second battery, the gate of the fifth power transistor is connected to the IO5 terminal of the first controller, the gate of the third power transistor is connected to the gate of the sixth power transistor and the IO2 terminal of the first controller, and the gate of the fourth power transistor is connected to the IO1 terminal of the first controller.

[0018] As a further embodiment of the present invention: the auxiliary management module also includes a seventh power transistor, an eighth power transistor, a ninth power transistor, a third inductor, and a second power transistor;

[0019] Preferably, the source of the seventh power transistor is connected to the source of the fifth power transistor, the drain of the seventh power transistor is connected to the drain of the eighth power transistor and connected to the drain of the ninth power transistor and the source of the second power transistor through the third inductor, the drain of the second power transistor is connected to the drain of the sixth power transistor, the source of the eighth power transistor is connected to the source of the fourth power transistor, the source of the ninth power transistor is connected to the second terminal of the third battery, the gate of the seventh power transistor is connected to the gate of the second power transistor and the IO3 terminal of the first controller, and the gates of the eighth power transistor and the ninth power transistor are respectively connected to the IO2 terminal and the IO6 terminal of the first controller.

[0020] As a further embodiment of the present invention: the auxiliary management module also includes an energy storage capacitor, a tenth power transistor, a fourth diode, a fourth inverter, a second capacitor, and a fourth thyristor;

[0021] Preferably, the first end of the energy storage capacitor is connected to one end of the second capacitor, the cathode of the third diode, and the drain of the tenth power transistor; the second end of the energy storage capacitor is connected to the other end of the second capacitor, the source of the eighth power transistor, and the cathode of the fourth thyristor; the anode of the fourth thyristor is connected to the second end of the third battery; the control terminal of the fourth thyristor is connected to the output terminal of the fourth inverter; the input terminal of the fourth inverter is connected to the IO7 terminal of the first controller; the cathode of the fourth diode is connected to the gate of the tenth power transistor and the IO8 terminal of the first controller; and the anode of the fourth diode is connected to the IO1 terminal of the first controller.

[0022] As a further embodiment of the present invention: the voltage detection module includes a first detection device, a second detection device, and a third detection device;

[0023] Preferably, the first end and the second end of the first detection device are respectively connected to the first end and the second end of the first battery, the first end and the second end of the second detection device are respectively connected to the first end and the second end of the second battery, the first end and the second end of the third detection device are respectively connected to the first end and the second end of the third battery, and the third end of the first detection device, the third end of the second detection device and the third end of the third detection device are respectively connected to the IO9 end, the IO10 end and the IO11 end of the first controller.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: The weak current intelligent control circuit of the battery management system of the present invention receives the voltage status of the first, second, and third battery modules detected by the voltage detection module from the micro-control module. Based on the magnitude and difference between the detected signal and the average battery voltage, the auxiliary management module is then controlled to store the electrical energy released by the first, second, or third battery modules and to perform charging compensation control on the first, second, or third battery modules to achieve battery equalization voltage regulation control. At the same time, during discharge, the battery modules with large voltage differences from the average battery will be disconnected, and the auxiliary management module will control the disconnected first, second, or third battery modules to perform series compensation power supply control to avoid increasing the discharge rate. While meeting the discharge requirements, the safety of the battery is ensured, and the discharge efficiency of the battery is improved. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic block diagram of a low-voltage intelligent control circuit for a battery management system provided in an embodiment of the present invention.

[0027] Figure 2 The circuit diagram is provided for a low-voltage intelligent control circuit of a battery management system according to an embodiment of the present invention.

[0028] Figure 3 The circuit diagram of the voltage detection module provided in the embodiment of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In one embodiment, see Figure 1 A low-voltage intelligent control circuit for a battery management system, comprising:

[0031] The charging and discharging module 1 is connected to the first battery module 2 and the auxiliary management module 7, and is used to receive DC power and perform charging control or receive power output from the first battery module 2 or the auxiliary management module 7 and perform discharging control.

[0032] The first battery module 2 is used to receive DC power and store and discharge it.

[0033] The second battery module 3 is connected to the first battery module 2 and is used to be connected in series with the first battery module 2 for energy storage and discharge.

[0034] The third battery module 4 is connected to the second battery module 3 and is used to be connected in series with the second battery module 3 for energy storage and discharge.

[0035] The voltage detection module 5 is connected to the first battery module 2, the second battery module 3 and the third battery module 4, and is used to detect the voltage of the first battery module 2, the second battery module 3 and the third battery module 4 and output the first voltage signal, the second voltage signal and the third voltage signal respectively.

[0036] The microcontroller module 6 is connected to the voltage detection module 5, the first battery module 2, the second battery module 3, the third battery module 4, and the auxiliary management module 7. It is used to receive the first voltage signal, the second voltage signal, and the third voltage signal, compare the voltage of the first voltage signal, the second voltage signal, and the third voltage signal with the average battery voltage, and control the auxiliary management module 7 to perform energy storage and independent discharge. During discharge, when the first voltage signal is less than the second voltage signal and the third voltage signal, and the difference between the first voltage signal and the average battery voltage is less than a set difference threshold, the first battery module 2 is controlled to be disconnected and the auxiliary management module 7 is controlled to perform series compensation power supply. When the second voltage signal is less than the first voltage signal and the third voltage signal, and the difference between the second voltage signal and the average battery voltage is less than the difference threshold, the second battery module 3 is controlled to be disconnected and the auxiliary management module 7 is controlled to perform series compensation power supply. When the third voltage signal is less than the second voltage signal and the first voltage signal, and the difference between the third voltage signal and the average battery voltage is less than a set difference threshold, the third battery module 4 is controlled to be disconnected and the auxiliary management module 7 is controlled to perform series compensation power supply.

[0037] The auxiliary management module 7 is connected to the first battery module 2, the second battery module 3, and the third battery module 4. It is used to store DC power and release the stored power. During charging, discharging, or resting, it controls the discharge of the first battery module 2, the second battery module 3, or the third battery module 4 when the voltage is higher than the average battery voltage, releases the stored power, and provides charging compensation for the first battery module 2, the second battery module 3, and the third battery module 4 connected in series. During discharging, it replaces the first battery module 2, the second battery module 3, or the third battery module 4 when it is in an open circuit state to provide series compensation power.

[0038] In a specific embodiment, the charging / discharging module 1 can be composed of a charging / discharging control device and a capacitor to perform bidirectional power transmission control, thereby connecting to and receiving power to achieve charging and discharging control; the first battery module 2 can be a first battery circuit composed of a battery, a thyristor, and an inverter to perform circuit breaking, energy storage, and discharging control; the second battery module 3 can be a second battery circuit composed of a battery, a thyristor, and an inverter to perform circuit breaking, energy storage, and discharging control; the third battery module 4 can be a third battery circuit composed of a battery, a thyristor, and an inverter to perform circuit breaking, energy storage, and discharging control; the voltage detection module 5 can be a voltage detection circuit composed of a detection device to perform voltage detection on the first battery module 2, the second battery module 3, and the third battery module 4; the microcontroller module 6 can be a microcontroller composed of a single-chip microcomputer. The control circuit integrates many components such as an arithmetic unit, a controller, a memory, and input / output devices. It realizes functions such as signal processing, data storage, module control, and timing control. It can also detect the relationship between the signal output by the voltage detection module 5 and the average battery voltage, calculate the voltage difference between the detected signal and the average battery voltage and the voltage difference threshold, and then determine the degree of voltage difference. The auxiliary management module 7 can be an auxiliary management circuit composed of field-effect transistors, inductors, energy storage capacitor CD1, and thyristors. By controlling the power transmission path, it can perform energy storage control and release of stored power, and perform charging compensation control or series compensation power supply control for the first battery module 2, the second battery module 3, and the third battery module 4, so as to realize balanced voltage regulation control for the first battery module 2, the second battery module 3, and the third battery module 4.

[0039] In another embodiment, please refer to Figure 1 , Figure 2 and Figure 3 The charging and discharging module 1 includes a charging and discharging control device and a first capacitor C1; the first battery module 2 includes a first thyristor S1, a first inverter J1 and a first battery; the second battery module 3 includes a second thyristor S2, a second inverter J2 and a second battery; the third battery module 4 includes a third thyristor S3, a third battery and a third inverter J3; and the microcontroller module 6 includes a first controller U1.

[0040] Specifically, the first terminal of the charge / discharge control device is connected to the first terminal of the first thyristor S1 and connected to the second terminal of the charge / discharge control device and the second terminal of the third battery through the first capacitor C1. The second terminal of the first thyristor S1 is connected to the first terminal of the first battery. The second terminal of the first battery is connected to one terminal of the second thyristor S2. The other terminal of the second thyristor S2 is connected to the first terminal of the second battery. The second terminal of the second battery is connected to one terminal of the third thyristor S3. The other terminal of the third thyristor S3 is connected to the first terminal of the third battery. The control terminals of the first thyristor S1, the second thyristor S2, and the third thyristor S3 are respectively connected to the output terminals of the first inverter J1, the second inverter J2, and the third inverter J3. The input terminals of the first inverter J1, the second inverter J2, and the third inverter J3 are respectively connected to the IO1, IO2, and IO3 terminals of the first controller U1.

[0041] In a specific embodiment, the first inverter J1, the second inverter J2, and the third inverter J3 can all be NOT gate chips; the first thyristor S1, the second thyristor S2, and the third thyristor S3 can all be bidirectional thyristors; the first controller U1 can be an STM32 microcontroller; and the charging and discharging control device can be a bidirectional DC-DC device.

[0042] Furthermore, the auxiliary management module 7 includes a first diode D1, a second diode D2, a first power transistor Q1, a third diode D3, and a first inductor L1;

[0043] Specifically, the anode of the first diode D1 is connected to the first terminal of the first thyristor S1, the cathode of the first diode D1 is connected to the cathode of the second diode D2 and is connected to the drain of the first power transistor Q1 and the anode of the third diode D3 through the first inductor L1, the source of the first power transistor Q1 is connected to the second terminal of the first battery, and the gate of the first power transistor Q1 is connected to the IO4 terminal of the first controller U1.

[0044] In a specific embodiment, the first power transistor Q1 can be an N-channel field-effect transistor.

[0045] Furthermore, the auxiliary management module 7 also includes a third power transistor Q3, a fourth power transistor Q4, a second inductor L2, a fifth power transistor Q5, and a sixth power transistor Q6;

[0046] Specifically, the source of the third power transistor Q3 is connected to the source of the first power transistor Q1, the source of the fourth power transistor Q4 is connected to the anode of the second diode D2, the drain of the third power transistor Q3 is connected to the drain of the fourth power transistor Q4 and is connected to the drain of the fifth power transistor Q5 and the source of the sixth power transistor Q6 through the second inductor L2, the drain of the sixth power transistor Q6 is connected to the cathode of the third diode D3, the source of the fifth power transistor Q5 is connected to the second terminal of the second battery, the gate of the fifth power transistor Q5 is connected to the IO5 terminal of the first controller U1, the gate of the third power transistor Q3 is connected to the gate of the sixth power transistor Q6 and the IO2 terminal of the first controller U1, and the gate of the fourth power transistor Q4 is connected to the IO1 terminal of the first controller U1.

[0047] In a specific embodiment, the third power transistor Q3, the fourth power transistor Q4, the fifth power transistor Q5, and the sixth power transistor Q6 can all be N-channel field-effect transistors.

[0048] Furthermore, the auxiliary management module 7 also includes a seventh power transistor Q7, an eighth power transistor Q8, a ninth power transistor Q9, a third inductor L3, and a second power transistor Q2;

[0049] Specifically, the source of the seventh power transistor Q7 is connected to the source of the fifth power transistor Q5, the drain of the seventh power transistor Q7 is connected to the drain of the eighth power transistor Q8 and connected to the drain of the ninth power transistor Q9 and the source of the second power transistor Q2 through the third inductor L3, the drain of the second power transistor Q2 is connected to the drain of the sixth power transistor Q6, the source of the eighth power transistor Q8 is connected to the source of the fourth power transistor Q4, the source of the ninth power transistor Q9 is connected to the second terminal of the third battery, the gate of the seventh power transistor Q7 is connected to the gate of the second power transistor Q2 and the IO3 terminal of the first controller U1, and the gates of the eighth power transistor Q8 and the ninth power transistor Q9 are respectively connected to the IO2 and IO6 terminals of the first controller U1.

[0050] In a specific embodiment, the second power transistor Q2, the seventh power transistor Q7, the eighth power transistor Q8, and the ninth power transistor Q9 can all be N-channel field-effect transistors.

[0051] Furthermore, the auxiliary management module 7 also includes an energy storage capacitor CD1, a tenth power transistor Q10, a fourth diode D4, a fourth inverter J4, a second capacitor C2, and a fourth thyristor S4;

[0052] Specifically, the first end of the energy storage capacitor CD1 is connected to one end of the second capacitor C2, the cathode of the third diode D3, and the drain of the tenth power transistor Q10. The second end of the energy storage capacitor CD1 is connected to the other end of the second capacitor C2, the source of the eighth power transistor Q8, and the cathode of the fourth thyristor S4. The anode of the fourth thyristor S4 is connected to the second end of the third battery. The control terminal of the fourth thyristor S4 is connected to the output terminal of the fourth inverter J4. The input terminal of the fourth inverter J4 is connected to the IO7 terminal of the first controller U1. The cathode of the fourth diode D4 is connected to the gate of the tenth power transistor Q10 and the IO8 terminal of the first controller U1. The anode of the fourth diode D4 is connected to the IO1 terminal of the first controller U1.

[0053] In a specific embodiment, the energy storage capacitor CD1 can be a supercapacitor; the tenth power transistor Q10 can be an N-channel MOSFET; and the fourth thyristor S4 can be a unidirectional thyristor.

[0054] Furthermore, the voltage detection module 5 includes a first detection device, a second detection device, and a third detection device;

[0055] Specifically, the first end and the second end of the first detection device are respectively connected to the first end and the second end of the first battery, the first end and the second end of the second detection device are respectively connected to the first end and the second end of the second battery, the first end and the second end of the third detection device are respectively connected to the first end and the second end of the third battery, and the third end of the first detection device, the third end of the second detection device and the third end of the third detection device are respectively connected to the IO9, IO10 and IO11 ends of the first controller U1.

[0056] In a specific embodiment, the first detection device, the second detection device, and the third detection device can all be composed of a resistor voltage divider circuit to perform voltage sampling.

[0057] In this embodiment, a low-voltage intelligent control circuit for a battery management system includes a charging and discharging control device that receives DC power during charging. The first thyristor S1, the second thyristor S2, and the third thyristor S3 are turned on, allowing the first, second, and third batteries to be charged in series. During discharging, the charging and discharging control device transmits the power supplied by the series connection of the first, second, and third batteries. The first, second, and third detection devices respectively detect the voltage and output a first voltage signal, a second voltage signal, and a third voltage signal. This allows the first controller U1 to control the auxiliary management module 7 to operate the first battery module 2 (with a voltage higher than the average battery voltage) during charging, discharging, or resting periods. The second battery module 3 or the third battery module 4 performs discharge control. For example, when the second voltage signal is higher than the average battery voltage, the IO5 terminal of the first controller U1 controls the seventh power transistor Q7 to turn on, so that the electrical energy released by the second battery passes through the second thyristor S2, the third power transistor Q3, the second inductor L2, and the fifth power transistor Q5 to form a circuit, and is stored by the second inductor L2. When the control of the fifth power transistor Q5 to turn on is stopped, the second inductor L2 releases electrical energy and forms a circuit with the energy storage capacitor CD1 through the sixth power transistor Q6 and the fourth power transistor Q4, so that the energy storage capacitor CD1 stores energy. The stored electrical energy is used by the first controller U1 to control the tenth power transistor Q10 to turn on when the first controller U1 controls the tenth power transistor Q10 to turn on, which is the first battery in series. The second and third batteries undergo charging compensation processing. During discharge, if the first voltage signal is lower than the second and third voltage signals, and the difference between the first voltage signal and the average battery voltage is less than a set difference threshold, the IO7 terminal of the first controller U1 controls the fourth thyristor S4 to turn off. The IO1 terminal of the first controller U1 controls the first thyristor S1 to turn off, disconnecting the first battery. Simultaneously, it triggers the tenth power transistor Q10 and the fourth power transistor Q4 to turn on, causing the energy storage capacitor CD1 to replace the first battery through the tenth power transistor Q10, the fourth power transistor Q4, and the third power transistor Q3, thus replacing the first battery in series with the second and third batteries for power supply. At this time, the electrical energy of the energy storage device can be supplied by... The first battery module 2, the second battery module 3, or the third battery module 4, which has a voltage higher than the average battery voltage, provide equalization. Similarly, when the second voltage signal is lower than the first and third voltage signals and the difference between the second voltage signal and the average battery voltage is less than the difference threshold, the IO7 terminal of the first controller U1 controls the fourth thyristor S4 to be turned off, and the energy storage capacitor CD1 replaces the second battery for series power supply. When the third voltage signal is lower than the second and first voltage signals and the difference between the third voltage signal and the average battery voltage is less than the set difference threshold, the IO7 terminal of the first controller U1 does not work, and the fourth inverter J4 triggers the fourth thyristor S4 to be turned on, so that the energy storage capacitor CD1 replaces the third battery for series power supply.

[0058] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0059] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A low-voltage intelligent control circuit for a battery management system, characterized in that, The circuit includes: The charging and discharging module is connected to the first battery module and the auxiliary management module, and is used to receive DC power and perform charging control or receive power output from the first battery module or the auxiliary management module and perform discharging control. The first battery module is used to receive DC power and store and discharge it. The second battery module is connected to the first battery module and is used to store energy and discharge energy in series with the first battery module. The third battery module is connected to the second battery module and is used to store energy and discharge energy in series with the second battery module. A voltage detection module is connected to the first battery module, the second battery module, and the third battery module, and is used to detect the voltage of the first battery module, the second battery module, and the third battery module and output a first voltage signal, a second voltage signal, and a third voltage signal respectively. The microcontroller module, connected to the voltage detection module, the first battery module, the second battery module, the third battery module, and the auxiliary management module, receives the first voltage signal, the second voltage signal, and the third voltage signal. It compares the magnitudes of the first voltage signal, the second voltage signal, and the third voltage signal with the average battery voltage and controls the auxiliary management module to perform energy storage and independent discharge. During discharge, when the first voltage signal is less than the second voltage signal and the third voltage signal, and the difference between the first voltage signal and the average battery voltage is less than a set difference threshold, the microcontroller module is controlled to disconnect and the auxiliary management module is controlled to perform series compensation power supply. When the second voltage signal is less than the first voltage signal and the third voltage signal, and the difference between the second voltage signal and the average battery voltage is less than the difference threshold, the microcontroller module is controlled to disconnect and the auxiliary management module is controlled to perform series compensation power supply. When the third voltage signal is less than the second voltage signal and the first voltage signal, and the difference between the third voltage signal and the average battery voltage is less than a set difference threshold, the microcontroller module is controlled to disconnect and the auxiliary management module is controlled to perform series compensation power supply. The auxiliary management module is connected to the first battery module, the second battery module, and the third battery module. It is used to store DC power and release the stored power. During charging, discharging, or resting, it controls the discharge of the first battery module, the second battery module, or the third battery module with a voltage higher than the average battery voltage, releases the stored power, and provides charging compensation for the first battery module, the second battery module, and the third battery module connected in series. During discharging, it replaces the first battery module, the second battery module, or the third battery module in the open circuit state to provide series compensation power. The charging and discharging module includes a charging and discharging control device and a first capacitor; the first battery module includes a first thyristor, a first inverter, and a first battery; the second battery module includes a second thyristor, a second inverter, and a second battery; the third battery module includes a third thyristor, a third battery, and a third inverter; the microcontroller module includes a first controller; The first terminal of the charge / discharge control device is connected to the first terminal of the first thyristor and is connected to the second terminal of the charge / discharge control device and the second terminal of the third battery through the first capacitor. The second terminal of the first thyristor is connected to the first terminal of the first battery. The second terminal of the first battery is connected to one terminal of the second thyristor. The other terminal of the second thyristor is connected to the first terminal of the second battery. The second terminal of the second battery is connected to one terminal of the third thyristor. The other terminal of the third thyristor is connected to the first terminal of the third battery. The control terminals of the first thyristor, the second thyristor, and the third thyristor are respectively connected to the output terminals of the first inverter, the second inverter, and the third inverter. The input terminals of the first inverter, the second inverter, and the third inverter are respectively connected to the IO1, IO2, and IO3 terminals of the first controller.

2. The low-voltage intelligent control circuit of a battery management system according to claim 1, characterized in that, The auxiliary management module includes a first diode, a second diode, a first power transistor, a third diode, and a first inductor; The anode of the first diode is connected to the first terminal of the first thyristor, the cathode of the first diode is connected to the cathode of the second diode and is connected to the drain of the first power transistor and the anode of the third diode through the first inductor, the source of the first power transistor is connected to the second terminal of the first battery, and the gate of the first power transistor is connected to the IO4 terminal of the first controller.

3. The low-voltage intelligent control circuit of a battery management system according to claim 2, characterized in that, The auxiliary management module also includes a third power transistor, a fourth power transistor, a second inductor, a fifth power transistor, and a sixth power transistor; The source of the third power transistor is connected to the source of the first power transistor, the source of the fourth power transistor is connected to the anode of the second diode, the drain of the third power transistor is connected to the drain of the fourth power transistor and connected to the drain of the fifth power transistor and the source of the sixth power transistor through the second inductor, the drain of the sixth power transistor is connected to the cathode of the third diode, the source of the fifth power transistor is connected to the second terminal of the second battery, the gate of the fifth power transistor is connected to the IO5 terminal of the first controller, the gate of the third power transistor is connected to the gate of the sixth power transistor and the IO2 terminal of the first controller, and the gate of the fourth power transistor is connected to the IO1 terminal of the first controller.

4. The low-voltage intelligent control circuit of a battery management system according to claim 3, characterized in that, The auxiliary management module also includes a seventh power transistor, an eighth power transistor, a ninth power transistor, a third inductor, and a second power transistor; The source of the seventh power transistor is connected to the source of the fifth power transistor, the drain of the seventh power transistor is connected to the drain of the eighth power transistor and connected to the drain of the ninth power transistor and the source of the second power transistor through the third inductor, the drain of the second power transistor is connected to the drain of the sixth power transistor, the source of the eighth power transistor is connected to the source of the fourth power transistor, the source of the ninth power transistor is connected to the second terminal of the third battery, the gate of the seventh power transistor is connected to the gate of the second power transistor and the IO3 terminal of the first controller, and the gates of the eighth power transistor and the ninth power transistor are respectively connected to the IO2 terminal and the IO6 terminal of the first controller.

5. The low-voltage intelligent control circuit of a battery management system according to claim 4, characterized in that, The auxiliary management module also includes an energy storage capacitor, a tenth power transistor, a fourth diode, a fourth inverter, a second capacitor, and a fourth thyristor; The first end of the energy storage capacitor is connected to one end of the second capacitor, the cathode of the third diode, and the drain of the tenth power transistor. The second end of the energy storage capacitor is connected to the other end of the second capacitor, the source of the eighth power transistor, and the cathode of the fourth thyristor. The anode of the fourth thyristor is connected to the second end of the third battery. The control terminal of the fourth thyristor is connected to the output terminal of the fourth inverter. The input terminal of the fourth inverter is connected to the IO7 terminal of the first controller. The cathode of the fourth diode is connected to the gate of the tenth power transistor and the IO8 terminal of the first controller. The anode of the fourth diode is connected to the IO1 terminal of the first controller.

6. The low-voltage intelligent control circuit of a battery management system according to claim 1, characterized in that, The voltage detection module includes a first detection device, a second detection device, and a third detection device; The first end and the second end of the first detection device are respectively connected to the first end and the second end of the first battery. The first end and the second end of the second detection device are respectively connected to the first end and the second end of the second battery. The first end and the second end of the third detection device are respectively connected to the first end and the second end of the third battery. The third end of the first detection device, the third end of the second detection device and the third end of the third detection device are respectively connected to the IO9, IO10 and IO11 ends of the first controller.

Images