BMS (Battery Management System) circuit with multiple charging protection for controlling positive electrode

Abstract

The utility model discloses a BMS (Battery Management System) circuit with multiple charging protection for controlling an anode, which comprises a control module, a charging and discharging circuit, a charging and discharging protection circuit, a charging over-temperature protection circuit and a secondary over-charging protection circuit, and is characterized in that the control module is electrically connected with the charging and discharging protection circuit, the charging over-temperature protection circuit and the secondary over-charging protection circuit respectively; and the charging and discharging protection circuit, the charging over-temperature protection circuit and the secondary over-charging protection circuit are electrically connected with the charging and discharging circuit and are used for driving the charging and discharging circuit to be switched on or switched off. When charging over-voltage, charging over-current or charging over-temperature occurs, the control module can control the MOS tube QC1 in the charging and discharging circuit to be cut off, so that a primary protection function is realized; or the charging MOS tube QC2 is controlled to be cut off, the charging current cannot flow through the QC2, charging is stopped, and the over-temperature protection function is achieved; and in addition, an independent secondary overcharge protection function can be realized, so that the protection capability of the BMS circuit can be improved, and the safety and the reliability are improved.

Description

Technical Field

[0001] This utility model relates to the field of battery management circuits, and in particular to a BMS circuit for multiple charging protection control of the positive electrode. Background Technology

[0002] Rechargeable lithium-ion batteries, a groundbreaking invention, are now widely used in consumer electronics, drones, electric vehicles, backup power supplies, and home energy storage. They have provided convenience for our daily lives, scientific research and education, and manufacturing, especially with the rapid development of new energy sources over the past decade. We know that rechargeable lithium-ion batteries are highly reactive, particularly in high-temperature environments. Improper use can lead to abnormal overheating, fires, or even explosions. Lithium-ion batteries are more prone to malfunctions during charging, necessitating the use of higher-performance Battery Management Systems (BMS) boards in lithium-ion battery pack production. This places new demands on charging protection.

[0003] There are many types of BMS protection boards on the market now. Low-end ones only have discharge protection function. Ordinary protection boards generally use hardware overcharge and over-discharge control protection functions. Advanced protection boards use MCU microprocessor + AFE analog front-end processing to achieve multi-functional protection. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a BMS circuit with multiple charging protection controls for the positive electrode.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] A BMS circuit for controlling the positive electrode with multiple charging protections includes: a control module, a charging / discharging circuit, a charging / discharging protection circuit, a charging over-temperature protection circuit, and a secondary overcharge protection circuit.

[0007] The control module is electrically connected to the charge-discharge protection circuit, the charging over-temperature protection circuit, and the secondary overcharge protection circuit, respectively. The charge-discharge protection circuit, the charging over-temperature protection circuit, and the secondary overcharge protection circuit are electrically connected to the charge-discharge circuit and are used to drive the charge-discharge circuit to turn on or off.

[0008] In one embodiment, the BMS circuit is used for electrical connection with the battery pack.

[0009] In one of the embodiments, the charging and discharging circuit comprises a charging MOS tube QC1 and a charging MOS tube QC2, an input end of the charging MOS tube QC1 is electrically connected with a positive electrode of the battery pack, an output end of the charging MOS tube QC1 is electrically connected with an input end of the charging MOS tube QC2, an output end of the charging MOS tube QC2 is used for outputting a charging voltage, a control end of the charging MOS tube QC1 is electrically connected with the control module, and control ends of the charging MOS tube QC2 are respectively electrically connected with the charging over-temperature protection circuit and the secondary over-charging protection circuit.

[0010] In one of the embodiments, the charging and discharging circuit further comprises a discharging MOS tube QD1, an input end of the discharging MOS tube QD1 is electrically connected with a negative electrode of the battery pack, and a control end of the discharging MOS tube QD1 is electrically connected with the control module.

[0011] In one of the embodiments, the control module comprises a primary protection chip, a secondary protection chip and an MCU unit, the primary protection chip is respectively electrically connected with the secondary protection chip and the MCU unit, the primary protection chip is further respectively electrically connected with the charging and discharging protection circuit, the charging over-temperature protection circuit and the secondary over-charging protection circuit, and the secondary protection chip is electrically connected with the secondary over-charging protection circuit.

[0012] In one of the embodiments, the primary protection chip is an AFE communication chip.

[0013] In one of the embodiments, the charging and discharging protection circuit comprises a transistor Q3 and a resistor R8, a control electrode of the transistor Q3 is electrically connected with the control module, a collector electrode of the transistor Q3 is electrically connected with the charging MOS tube QC1 through the resistor R8, and an emitter electrode of the transistor Q3 is grounded.

[0014] In one of the embodiments, the charging and discharging protection circuit further comprises a thermistor NTC, the thermistor NTC is electrically connected with the control module, and the thermistor NTC is used for sensing a temperature of the battery pack.

[0015] In one of the embodiments, the charging over-temperature protection circuit comprises a transistor Q1, a resistor R5, a resistor R6 and a temperature control switch, the temperature control switch is electrically connected with the control module, the temperature control switch is further electrically connected with one end of the resistor R6, the other end of the resistor R6 is electrically connected with a control electrode of the transistor Q1, a collector electrode of the transistor Q1 is electrically connected with the charging MOS tube QC2 through the resistor R5, and an emitter electrode of the transistor Q1 is grounded.

[0016] In one of the embodiments, the secondary overcharge protection circuit comprises a transistor Q2, a control electrode of the transistor Q2 is electrically connected with the control module, a collector electrode of the transistor Q2 is electrically connected with a control electrode of the transistor Q1, and an emitter electrode of the transistor Q2 is grounded.

[0017] Compared with the prior art, the BMS circuit has the following advantages and beneficial effects:

[0018] The utility model discloses a kind of multiple charging protection control anode's BMS circuit, by setting charge-discharge protection circuit, when overvoltage charging, overcurrent charging or overtemperature charging occurs, control module can control MOS tube QC1 in charge-discharge circuit cut-off, charging current cannot flow through QC1, stop charging, realize primary protection function;And by setting overtemperature charging protection circuit, when battery pack temperature exceeds temperature control switch protection threshold value, temperature control switch opens state, control signal cannot drive charging MOS tube QC2 in charge-discharge circuit, charging MOS tube QC2 cut-off, charging current cannot flow through QC2, stop charging, realize overtemperature protection function;In addition, by setting secondary overcharge protection circuit, when overvoltage charging occurs, OV2 signal of control module will stop, charging MOS tube QC2 cut-off, charging current cannot flow through QC2, stop charging, realize independent secondary overcharge protection function, to improve the protection capability of BMS circuit, improve safety and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is circuit schematic diagram of the BMS circuit of multiple charging protection control anode of an embodiment of the utility model;

[0020] Figure 2 It is circuit diagram of the BMS circuit of multiple charging protection control anode shown in Figure 1 DETAILED DESCRIPTION

[0021] In order to facilitate understanding of the utility model, the utility model will be described more comprehensively below with reference to relevant drawings. Preferred embodiments of the utility model are shown in the drawings. However, the utility model can be realized in many different forms, and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the utility model more thorough and comprehensive.

[0022] Please refer to Figures 1-2 A kind of BMS circuit of multiple charging protection control anode, including: control module, charge-discharge circuit, charge-discharge protection circuit, overtemperature charging protection circuit and secondary overcharge protection circuit, the BMS circuit is used to be electrically connected with battery pack.

[0023] ​The control module is electrically connected with the charge-discharge protection circuit, the charging over-temperature protection circuit and the secondary over-charge protection circuit respectively, the charge-discharge protection circuit, the charging over-temperature protection circuit and the secondary over-charge protection circuit are electrically connected with the charge-discharge circuit, and are used for driving the charge-discharge circuit to be turned on or turned off.

[0024] It is to be noted that the control module is electrically connected with the charge-discharge protection circuit, the charging over-temperature protection circuit and the secondary over-charge protection circuit. It is responsible for receiving instructions or voltage signals from various circuits, performing real-time analysis and processing, and issuing instructions to other circuits according to the analysis results. The charge-discharge protection circuit can monitor the charge-discharge state of the battery pack in real time, ensuring that the battery works within a safe voltage and current range. Once the battery pack has abnormal conditions such as overcharging, over-discharging, over-temperature or short circuit, the charge-discharge protection circuit will respond immediately by driving the charge-discharge circuit to be turned on or turned off to cut off the connection between the battery pack and the load or charger, thereby protecting the battery from damage. The charging over-temperature protection circuit is used to monitor the temperature of the battery during charging. When the battery temperature exceeds the preset safe range, the circuit will quickly start to prevent the battery from overheating by cutting off the charging circuit or reducing the charging current, thereby avoiding potential safety risks. The secondary over-charge protection circuit provides an additional layer of safety protection. It can more accurately determine whether the battery is in an over-charge over-voltage state. Once the battery is confirmed to be over-charge over-voltage, the circuit will take action immediately by driving the charge-discharge circuit to be turned off to prevent the battery from being further damaged.

[0025] In the embodiment, the charge-discharge circuit includes a charging MOS tube QC1 and a charging MOS tube QC2, an input end of the charging MOS tube QC1 is electrically connected with a positive electrode of the battery pack, an output end of the charging MOS tube QC1 is electrically connected with an input end of the charging MOS tube QC2, an output end of the charging MOS tube QC2 is used for outputting a charging voltage, a control end of the charging MOS tube QC1 is electrically connected with the control module, and a control end of the charging MOS tube QC2 is electrically connected with the charging over-temperature protection circuit and the secondary over-charge protection circuit respectively. Further, the charge-discharge circuit further includes a discharging MOS tube QD1, an input end of the discharging MOS tube QD1 is electrically connected with a negative electrode of the battery pack, and a control end of the discharging MOS tube QD1 is electrically connected with the control module. In this way, the charging MOS tube QC1 and the charging MOS tube QC2 are used to jointly control the charging of the battery pack, and the discharging MOS tube QD1 is used to control the discharging of the battery pack.

[0026] It should be noted that the control module includes a primary protection chip, a secondary protection chip and an MCU unit, the primary protection chip is electrically connected with the secondary protection chip and the MCU unit respectively, the primary protection chip is also electrically connected with the charge and discharge protection circuit, the charge over-temperature protection circuit and the secondary over-charge protection circuit respectively, and the secondary protection chip is electrically connected with the secondary over-charge protection circuit. In the embodiment, the primary protection chip is an AFE communication chip. In this way, the configuration of the MCU unit and the AFE communication chip can realize the function of the scalable multi-protection circuit with communication, the AFE communication chip can collect information such as voltage, current and temperature of the battery pack, and report the information to the MCU unit through IIC communication, and the MCU unit can further give instructions to the AFE to turn on or turn off the charge and discharge MOS, so as to realize the multi-functional protection requirement. In addition, the MCU unit can realize the external communication function, thereby providing a friendly interface for the secondary multi-functional development and application of the product. In the embodiment, the primary protection chip is a primary protection IC, and the secondary protection chip is a secondary protection IC.

[0027] Please refer to Figure 2 The charge and discharge protection circuit includes a transistor Q3 and a resistor R8, the control electrode of the transistor Q3 is electrically connected with the control module, the collector of the transistor Q3 is electrically connected with the charge MOS tube QC1 through the resistor R8, and the emitter of the transistor Q3 is grounded. It should be noted that in the normal working mode, the CHG signal of the primary protection IC / AFE drives the charge MOS tube QC1 to turn on through the transistor Q3 and the resistor R8, and the charging current can flow through the QC1. When the charging over-voltage, the charging over-current or the charging over-temperature occurs, the CHG signal of the primary protection IC / AFE will stop, the charge MOS tube QC1 will be turned off, the charging current cannot flow through the charge MOS tube QC1, the charging is stopped, and the protection function is realized. The temperature of the BAT can be detected by the temperature sensor NTC and reported to the primary protection IC / AFE. Similarly, the DSG signal of the primary protection IC / AFE can drive the discharge MOS tube QD1 to turn on or turn off, so as to realize the discharge under-voltage, the discharge over-temperature, the discharge over-current and the short circuit protection function. Further, the charge and discharge protection circuit further includes a thermistor NTC, the thermistor NTC is electrically connected with the control module, and the thermistor NTC is used for sensing the temperature of the battery pack.

[0028] Please refer to Figure 2The charging over-temperature protection circuit comprises a triode Q1, a resistor R5, a resistor R6 and a temperature control switch, the temperature control switch is electrically connected with the control module, one end of the resistor R6 is electrically connected with the temperature control switch, the other end of the resistor R6 is electrically connected with the control electrode of the triode Q1, the collector of the triode Q1 is electrically connected with the charging MOS tube QC2 through the resistor R5, and the emitter of the triode Q1 is grounded.

[0029] Please refer to Figure 2 The secondary over-charging protection circuit comprises a triode Q2, the control electrode of the triode Q2 is electrically connected with the control module, the collector of the triode Q2 is electrically connected with the control electrode of the triode Q1, and the emitter of the triode Q2 is grounded. It should be noted that, in the normal working mode, the OV2 signal of the secondary protection IC can drive the charging MOS tube QC2 to be turned on through the triode Q2, the triode Q1 and the resistor R5, and the charging current can flow through the charging MOS tube QC2; when overvoltage charging occurs, the OV2 signal of the secondary protection IC stops, the charging MOS tube QC2 is cut off, the charging current cannot flow through the charging MOS tube QC2, and the charging is stopped, thereby realizing the independent secondary over-charging protection function.

[0030] When the MCU+AFE combined circuit is selected, an external communication interface circuit can be provided, and the battery voltage, current and temperature information can be reported to the external main control MCU through the communication mode; meanwhile, the external main control MCU can control the conduction or cut-off of the main loop MOSFET through the communication command mode, and a friendly interface is provided for the development of intelligent devices.

[0031] The above-mentioned embodiments only express several embodiments of the utility model, the description is more specific and detailed, but it cannot be understood as the limitation of the utility model patent range. It should be noted that, for ordinary skilled persons in the art, without departing from the concept of the utility model, a number of modifications and improvements can be made, which belong to the protection range of the utility model. Therefore, the protection range of the utility model patent should be subject to the appended claims.

Claims

1. A BMS circuit for controlling a positive electrode of a multiple charging protection, characterized in that, The application relates to a battery management system (BMS) circuit. The BMS circuit comprises a control module, a charge-discharge circuit, a charge-discharge protection circuit, a charging over-temperature protection circuit and a secondary over-charge protection circuit. The control module is electrically connected with the charge-discharge protection circuit, the charging over-temperature protection circuit and the secondary over-charge protection circuit respectively, and the charge-discharge protection circuit, the charging over-temperature protection circuit and the secondary over-charge protection circuit are electrically connected with the charge-discharge circuit and used for driving the charge-discharge circuit to be turned on or turned off.

2. The multiple charge protection control positive BMS circuit of claim 1, wherein, The BMS circuit is used for being electrically connected with a battery pack.

3. The multiple charge protection control positive BMS circuit of claim 2, wherein, The charge-discharge circuit comprises a charging MOS tube QC1 and a charging MOS tube QC2, the input end of the charging MOS tube QC1 is electrically connected with the positive pole of the battery pack, the output end of the charging MOS tube QC1 is electrically connected with the input end of the charging MOS tube QC2, the output end of the charging MOS tube QC2 is used for outputting a charging voltage, the control end of the charging MOS tube QC1 is electrically connected with the control module, and the control end of the charging MOS tube QC2 is electrically connected with the charging over-temperature protection circuit and the secondary over-charge protection circuit respectively.

4. The multiple charge protection control positive BMS circuit of claim 2, wherein, The charge-discharge circuit further comprises a discharging MOS tube QD1, the input end of the discharging MOS tube QD1 is electrically connected with the negative pole of the battery pack, and the control end of the discharging MOS tube QD1 is electrically connected with the control module.

5. The multiple charge protection control positive BMS circuit of claim 1, wherein, The control module comprises a primary protection chip, a secondary protection chip and an MCU unit, the primary protection chip is electrically connected with the secondary protection chip and the MCU unit respectively, and the primary protection chip is further electrically connected with the charge-discharge protection circuit, the charging over-temperature protection circuit and the secondary over-charge protection circuit respectively, and the secondary protection chip is electrically connected with the secondary over-charge protection circuit.

6. The multiple charge protection control positive BMS circuit of claim 5, wherein, The primary protection chip is an AFE communication chip.

7. The multiple charge protection control positive BMS circuit of claim 3, wherein, The charge-discharge protection circuit comprises a triode Q3 and a resistor R8, the control electrode of the triode Q3 is electrically connected with the control module, the collector of the triode Q3 is electrically connected with the charging MOS tube QC1 through the resistor R8, and the emitter of the triode Q3 is grounded.

8. The multiple charge protection control positive BMS circuit of claim 7, wherein, The charge-discharge protection circuit further comprises a thermistor NTC, the thermistor NTC is electrically connected with the control module, and the thermistor NTC is used for sensing the temperature of the battery pack.

9. The multiple charge protection control positive BMS circuit of claim 3, wherein, The charging over-temperature protection circuit comprises a triode Q1, a resistor R5, a resistor R6 and a temperature control switch, the temperature control switch is electrically connected with the control module, the temperature control switch is further electrically connected with one end of the resistor R6, the other end of the resistor R6 is electrically connected with the control electrode of the triode Q1, the collector of the triode Q1 is electrically connected with the charging MOS tube QC2 through the resistor R5, and the emitter of the triode Q1 is grounded.

10. The multiple charge protection control positive BMS circuit of claim 9, wherein, The secondary over-charge protection circuit comprises a triode Q2, the control electrode of the triode Q2 is electrically connected with the control module, the collector of the triode Q2 is electrically connected with the control electrode of the triode Q1, and the emitter of the triode Q2 is grounded.

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