Relay control module in battery management system

Abstract

The utility model discloses a relay control module in a battery management system, which comprises a first step-down circuit and a second step-down circuit which are connected in parallel at the positive electrode of a battery pack, and a battery microprocessor connected with the first step-down circuit, the voltage adjusting circuit and the relay driving control circuit are connected with the second voltage reduction circuit and the battery microprocessor, and the current sampling circuit and the relay are connected with the negative electrode of the battery pack in series. The current sampling circuit is also connected with the battery microprocessor; according to the utility model, the output voltage of the second step-down circuit is reduced by controlling the voltage regulation circuit, so that the driving voltage of the relay is reduced, the relay can use high voltage to ensure the pull-in force during pull-in, the driving voltage is reduced during holding, the power consumption of the relay can be reduced, and the service life of the relay is prolonged. The heating problem of the relay is reduced, and the electric quantity of the battery is saved to a certain extent.

Description

Technical Field

[0001] This utility model relates to the field of battery management system technology, and in particular to a relay control module in a battery management system. Background Technology

[0002] In the design of high-current battery management systems, the selection of the main circuit switch is crucial, as it directly affects the system's performance and efficiency. Currently, due to considerations such as technology and cost, relays are often used as the main circuit switch for battery packs to replace MOSFETs. However, this alternative has some significant drawbacks in practical applications.

[0003] Relays require significant pull-in power to activate and hold power to maintain normal operation. This can lead to excessive heat generation during operation, affecting their stability and lifespan, and may also excessively drain the battery, reducing the overall efficiency of the battery management system. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a relay control module in a battery management system. By controlling the voltage adjustment circuit to lower the output voltage of the second step-down circuit, the driving voltage of the relay is reduced, so that the relay can use a high voltage to ensure the engagement force when it is engaged, and reduce the driving voltage when it is held. This can reduce the power consumption of the relay, help reduce the heat generation of the relay, and also save battery power to a certain extent.

[0005] To achieve the above objectives, the specific solution of this utility model is as follows:

[0006] A relay control module in a battery management system includes a first step-down circuit and a second step-down circuit connected in parallel to the positive terminal of a battery pack, a battery microprocessor connected to the first step-down circuit, a voltage adjustment circuit and a relay drive control circuit connected to the second step-down circuit and the battery microprocessor, and a current sampling circuit and a relay connected in series to the negative terminal of the battery pack; the current sampling circuit is also connected to the battery microprocessor.

[0007] Further, the second step-down circuit of this utility model includes a step-down transformer VU1, a capacitor VC1, a resistor VR2, an inductor VL1, a capacitor VC6, a resistor VR4, a resistor VR10, and a resistor VR9; the step-down transformer VU1 is connected to the positive terminal of the battery pack; one end of the series connection of capacitor VC1, resistor VR2, and inductor VL1 is connected to the step-down transformer VU1, and the other end is connected to one end of resistor VR9; the other end of resistor VR9 is grounded; one end of the series connection of resistor VR4 and resistor VR10 is connected to one end of resistor VR9, and the other end is grounded; capacitor VC6 is connected in parallel with resistor VR4; the common terminal of resistor VR4 and resistor VR10 is connected to the step-down transformer VU1; the voltage adjustment circuit is connected to the common terminal of resistor VR4 and resistor VR10; a V14 node is provided at one end of resistor VR9.

[0008] Furthermore, the second step-down circuit of this invention also includes capacitors VC5, VC8, VC9 and VC10; capacitors VC5, VC8, VC9 and VC10 are connected in parallel with resistor VR9.

[0009] Furthermore, the present invention provides a step-down converter, model VU1, which is a step-down converter of model MK9019.

[0010] Furthermore, the second step-down circuit of this invention also includes capacitor VC4, Zener diode VC1, resistor VR3, resistor VR14, capacitor VC11, and resistor VR15; the Vin pin of step-down transformer VU1 is connected to the positive terminal of the battery pack, and the EN pin of step-down transformer VU1 is connected in series with resistor VR3 and then connected to the Vin pin of step-down transformer VU1; one end of capacitor VC4 and Zener diode VC1 connected in parallel is connected to the Vin pin of step-down transformer VU1, and the other end is grounded; one end of resistor VR14 and capacitor VC11 connected in parallel is connected to the EN pin of step-down transformer VU1, and the other end is grounded; one end of resistor VR15 is connected to the RT pin of step-down transformer VU1, and the other end is grounded.

[0011] Further, the voltage adjustment circuit of this invention includes a resistor VR12, a MOSFET VQ4, a resistor VR25, and a resistor VR38; the drain of the MOSFET VQ4 is connected in series with the resistor VR12 and then connected to the second step-down circuit; the source of the MOSFET VQ4 is grounded; one end of the resistor VR25 is connected to the gate of the MOSFET VQ4, and the other end is connected to the first step-down circuit; one end of the resistor VR38 is connected to the gate of the MOSFET VQ4, and the other end is connected to the battery microprocessor.

[0012] Furthermore, the relay drive control circuit of this invention includes transistors PQ1 and PQ2, MOSFET PM1, and bidirectional breakdown diode TVS1; the emitter of transistor PQ1 is connected to the second step-down circuit, the base of transistor PQ1 is connected to the collector of transistor PQ2, and the collector of transistor PQ1 is connected to the gate of MOSFET PM1; the base of transistor PQ2 is connected to the battery microprocessor, and the emitter of transistor PQ2 is grounded; the source of MOSFET PM1 is grounded; one end of the bidirectional breakdown diode TVS1 is connected to the second step-down circuit, and the other end is connected to the drain of MOSFET PM1; both ends of the bidirectional breakdown diode TVS1 are also connected to the relay.

[0013] Furthermore, the relay drive control circuit of this invention also includes a transistor PQ3 and a Zener diode ZD2; the emitter of transistor PQ3 is connected to the gate of MOSFET PM1, and the base of transistor PQ3 is connected to the collector of transistor PQ1; the collector of transistor PQ3 is grounded; one end of Zener diode ZD2 is connected to the gate of MOSFET PM1, and the other end is grounded.

[0014] Further, the first step-down circuit of this utility model includes a step-down transformer VU2, capacitors VC3, VC7, VC12, VC2, and a Zener diode VZ1; the Vin pin of the step-down transformer VU2 is connected to the positive terminal of the battery pack, the GND pin of the step-down transformer VU2 is grounded, one end of the parallel connection of capacitors VC3 and VC7 is connected to the Vin pin of the step-down transformer VU2, and the other end is grounded; one end of the parallel connection of capacitors VC12, VC2, and Zener diode VZ1 is connected to the Vout pin of the step-down transformer VU2, and the other end is grounded; the Vout pin of the step-down transformer VU2 is provided with a VSYS node.

[0015] Furthermore, this invention also includes a pre-charge-discharge circuit connected in parallel with the relay; the pre-charge-discharge circuit is connected to the battery microprocessor.

[0016] The beneficial effects of this utility model are as follows: During charging / discharging, the battery microprocessor collects the current magnitude and duration through the current sampling circuit, thereby controlling the voltage adjustment circuit to lower the output voltage of the second step-down circuit, thus reducing the relay's driving voltage. This allows the relay to use a high voltage to ensure the engaging force when it is engaged, while reducing the driving voltage when it is held, thereby reducing the relay's power consumption, helping to reduce the relay's heat generation, and also saving battery power to a certain extent. Attached Figure Description

[0017] Figure 1 This is a structural block diagram provided in an embodiment of the present utility model;

[0018] Figure 2This is a structural schematic diagram provided by an embodiment of the present utility model;

[0019] Figure 3 This is a partial structural schematic diagram of the battery microprocessor provided in this embodiment of the utility model;

[0020] Figure 4 This is a schematic diagram of the relay structure provided in this embodiment of the utility model;

[0021] Figure 5 This is a schematic diagram of the second step-down circuit provided in this embodiment of the present invention;

[0022] Figure 6 This is a schematic diagram of the voltage adjustment circuit provided in this embodiment of the utility model;

[0023] Figure 7 This is a schematic diagram of the relay drive control circuit provided in this embodiment of the utility model;

[0024] Figure 8 This is a schematic diagram of the first step-down circuit provided in this embodiment of the present invention;

[0025] Figure 9 This is a schematic diagram of the pre-charge-discharge circuit provided in this embodiment of the utility model;

[0026] Explanation of reference numerals in the attached figures: 100, First step-down circuit; 200, Second step-down circuit; 300, Battery microprocessor; 400, Voltage adjustment circuit; 500, Relay drive control circuit; 600, Current sampling circuit; 700, Pre-charge / discharge circuit; 800, Load detection circuit; 900, Charging detection circuit. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but this is not to limit the scope of the present invention.

[0028] like Figures 1 to 9 As shown, the relay control module in a battery management system according to this embodiment includes a first step-down circuit 100 and a second step-down circuit 200 connected in parallel to the positive terminal of the battery pack; a battery microprocessor 300 connected to the first step-down circuit 100; a voltage adjustment circuit 400 and a relay drive control circuit 500 connected to the second step-down circuit 200 and the battery microprocessor 300; and a current sampling circuit 600 and a relay connected in series to the negative terminal of the battery pack; the current sampling circuit 600 is also connected to the battery microprocessor 300. In this embodiment, a pre-charge / discharge circuit 700 connected in parallel with the relay is also included; the pre-charge / discharge circuit 700 is connected to the battery microprocessor 300.

[0029] Specifically, the first step-down circuit 100 mainly supplies power to the battery microprocessor 300; the second step-down circuit 200 performs voltage conversion and outputs the voltage to the relay drive control circuit 500. In actual use, the battery microprocessor 300 is connected to a load detection circuit 800 and a charging detection circuit 900. In the initial state of the battery, the battery microprocessor 300 closes the relay drive control circuit 500. When a charger or load is detected, the battery microprocessor 300 opens the pre-charge / discharge circuit 700 to pre-discharge or pre-charge for a certain time T. Then, the battery microprocessor 300 opens the relay drive control circuit 500 and closes the pre-charge / discharge circuit 700. The relay drive control circuit 500 connects the relay to the battery circuit, thereby charging or discharging. When the battery microprocessor 300 detects through the current sampling circuit 600 that the discharge or charging current is greater than the threshold A and lasts for a certain time H, the battery microprocessor 300 considers the battery to be in a stable state of discharge or charging. At this time, the battery microprocessor 300 controls the voltage adjustment circuit 400 to lower the output voltage of the second step-down circuit 200 to a certain value VL. This output voltage value VL can still keep the relay connected to the battery circuit until the discharge or charging ends.

[0030] In this embodiment, the battery microprocessor 300 collects the current magnitude and duration through the current sampling circuit 600 during charging / discharging. This allows the control voltage adjustment circuit 400 to lower the output voltage of the second step-down circuit 200, thereby reducing the relay's driving voltage. This enables the relay to use a high voltage to ensure the engagement force when it is engaged, while reducing the driving voltage when it is held. This reduces the relay's power consumption, helps reduce the relay's heat generation, and also saves battery power to some extent.

[0031] In addition, in this embodiment, during charging / discharging, the battery microprocessor 300 first opens the pre-charge / discharge circuit 700 and then controls the relay to work, thereby helping to avoid the problem of relay arcing and extending the service life of the relay.

[0032] Specifically, in this embodiment, as Figure 2 and Figure 3 As shown, the battery microprocessor LU1 is model HC32L072KATA. The VDD pin of the battery microprocessor LU1 is connected to the first step-down circuit 100, the GND pin of the battery microprocessor LU1 is grounded, and the IO pins of the battery microprocessor LU1 include CONT, EN_8V, DSG, and CHG terminals. The CONT terminal of the battery microprocessor LU1 is connected to the relay drive control circuit 500, and the EN_8V terminal of the battery microprocessor LU1 is connected to the voltage adjustment circuit 400. The DSG and CHG terminals of the battery microprocessor LU1 are respectively connected to the pre-charge / discharge circuit 700. In this embodiment, as... Figure 2 and Figure 4 As shown, the SW1 and SW2 pins of relay RY1 are connected in series on the negative terminal of the battery pack. The ON and COM pins of relay RY1 are respectively led out to the ON1 and VDDR connection terminals. The ON1 and VDDR connection terminals of relay RY1 are respectively connected to the relay drive control circuit 500. In this embodiment, as... Figure 1 As shown, the current sampling circuit 600 includes a sampling resistor RS1, which is connected in series in the negative terminal of the battery pack. By sampling the current of the sampling resistor RS1, the magnitude of the charging / discharging current can be obtained so that the battery microprocessor LU1 can control it.

[0033] like Figure 2 and Figure 5 As shown, in some embodiments of the relay control module of the battery management system in this embodiment, the second step-down circuit 200 includes a step-down converter VU1, a capacitor VC1, a resistor VR2, an inductor VL1, a capacitor VC6, a resistor VR4, a resistor VR10, and a resistor VR9; the second step-down circuit 200 also includes a capacitor VC4, a Zener diode VC1, a resistor VR3, a resistor VR14, a capacitor VC11, and a resistor VR15; the step-down converter VU1 is a step-down converter of model MK9019; the Vin pin of the step-down converter VU1 is connected to the positive terminal of the battery pack; the EN pin of the step-down converter VU1 is connected in series with the resistor VR3 and then connected to the Vin pin of the step-down converter VU1; one end of the parallel connection of the capacitor VC4 and the Zener diode VC1 is connected to the Vin pin of the step-down converter VU1, and the other end... Grounded; one end of the parallel connection of resistor VR14 and capacitor VC11 is connected to the EN pin of step-down transformer VU1, and the other end is grounded; one end of resistor VR15 is connected to the RT pin of step-down transformer VU1, and the other end is grounded; one end of the series connection of capacitor VC1, resistor VR2, and inductor VL1 is connected to the BOOT pin of step-down transformer VU1, and the other end is connected to one end of resistor VR9; the other end of resistor VR9 is grounded; one end of the series connection of resistors VR4 and VR10 is connected to one end of resistor VR9, and the other end is grounded; capacitor VC6 is connected in parallel with resistor VR4; the common terminal of resistors VR4 and VR10 is connected to the FB pin of step-down transformer VU1; voltage adjustment circuit 400 is connected to the common terminal of resistors VR4 and VR10; one end of resistor VR9 is provided with a V14 node. In this embodiment, the second step-down circuit 200 further includes capacitors VC5, VC8, VC9 and VC10; capacitors VC5, VC8, VC9 and VC10 are connected in parallel with resistor VR9; this arrangement makes the output voltage at node V14 more stable.

[0034] In this embodiment, through the above settings, the drive voltage required by the relay drive control circuit 500 is output at node V14 to control whether relay RY1 works; the battery microprocessor LU1 controls the output voltage at node V14 through voltage adjustment circuit 400, so that after the charging / discharging current stabilizes for a certain period of time H, the drive voltage of relay RY1 can be reduced to reduce the heat generation problem of relay RY1.

[0035] like Figure 2 and Figure 6 As shown, in some embodiments of the battery management system, the relay control module includes a voltage adjustment circuit 400 comprising a resistor VR12, a MOSFET VQ4, a resistor VR25, and a resistor VR38. The drain of the MOSFET VQ4 is connected in series with the resistor VR12 and then connected to the second step-down circuit 200. The source of the MOSFET VQ4 is grounded. One end of the resistor VR25 is connected to the gate of the MOSFET VQ4, and the other end is connected to the first step-down circuit 100. One end of the resistor VR38 is connected to the gate of the MOSFET VQ4, and the other end is connected to the battery microprocessor LU1.

[0036] Specifically, the drain of MOSFET VQ4 is connected in series with resistor VR12 and then connected to the common terminal of resistors VR4 and VR10. That is, resistor VR12 is connected to the FB pin of buck converter VU1, and the other end of resistor VR38 is connected to the EN_8V terminal of battery microprocessor LU1. In actual use, the EN_8V terminal of battery microprocessor LU1 controls the conduction state of MOSFET VQ4 by controlling the gate level of MOSFET VQ4, thereby adjusting the output voltage at node V14. After the charging / discharging current stabilizes for a certain period of time H, the drive voltage of relay RY1 is reduced to reduce the heat generation of relay RY1.

[0037] like Figure 2 and Figure 7 As shown, in some embodiments of the battery management system, the relay control module includes a relay drive control circuit 500 comprising transistors PQ1 and PQ2, a MOSFET PM1, and a bidirectional breakdown diode TVS1. The emitter of transistor PQ1 is connected to the second step-down circuit 200, the base of transistor PQ1 is connected to the collector of transistor PQ2 and the second step-down circuit 200, and the collector of transistor PQ1 is connected to the gate of MOSFET PM1. The base of transistor PQ2 is connected to the battery microprocessor 300, and the emitter of transistor PQ2 is grounded. The source of MOSFET PM1 is grounded. One end of the bidirectional breakdown diode TVS1 is connected to the second step-down circuit 200, and the other end is connected to the drain of MOSFET PM1. The two ends of the bidirectional breakdown diode TVS1 are also connected to the ON1 terminal and the VDDR terminal of relay RY1.

[0038] Specifically, the emitter of transistor PQ1 is connected to node V14, the base of transistor PQ2 is connected to the CONT terminal of battery microprocessor LU1, and one end of bidirectional breakdown diode TVS1 is connected to node V14. When transistor PQ2 is turned on by the CONT terminal of battery microprocessor LU1, transistor PQ1 and MOSFET PM1 are turned on, thus connecting the battery circuit through pins SW1 and SW2 of relay RY1. When transistor PQ2 is turned off by the CONT terminal of battery microprocessor LU1, both transistor PQ1 and MOSFET PM1 are turned off, thus disconnecting the battery circuit through pins SW1 and SW2 of relay RY1. Thus, by controlling the on / off state of transistor PQ2, the on / off state of relay RY1 can be controlled.

[0039] Furthermore, such as Figure 7As shown, the relay drive control circuit 500 also includes resistor PR1, capacitor PC1, resistor PR2, resistor PR7, diode PD1, diode PD2, capacitor PC2, resistor PR3, resistor PR5, resistor PR6, resistor PR8, resistor PR9, resistor PR10, capacitor EC1, capacitor PC3, diode PD4, and resistor PR12; one end of resistor PR1 is connected to node V14; the positive terminal of diode PD1 is connected in parallel with the positive terminal of diode PD2 and then connected to the other end of resistor PR1; the negative terminal of diode PD1 is connected to one end of bidirectional breakdown diode TVS1; one end of capacitor PC1 and resistor PR2 connected in parallel is connected to the negative terminal of diode PD1; the other end of capacitor PC1 and resistor PR2 connected in parallel is grounded; one end of resistor PR7 is connected to the other end of bidirectional breakdown diode TVS1; the other end of resistor PR7 is connected to the drain of MOSFET PM1; the negative terminal of diode PD2 is connected to the emitter of transistor PQ1; capacitor PC2... One end of resistor PR1 is connected to the negative terminal of diode PD2, and the other end is grounded; one end of resistor PR3 is connected to the negative terminal of diode PD2, and the other end is connected to the base of transistor PQ1; one end of resistor PR5 is connected to the base of transistor PQ1, and the other end is connected to the collector of transistor PQ1; one end of resistor PR8 is connected to the base of transistor PQ2, and the other end is connected to the CONT terminal of battery microprocessor LU1; one end of capacitor EC1 is connected to one end of resistor PR8, and the other end is grounded; one end of capacitor PC3 and resistor PR10 connected in parallel is connected to the base of transistor PQ2, and the other end is grounded; one end of resistor PR6 is connected to the base of transistor PQ2, and the other end is connected to the first step-down circuit 100; one end of resistor PR9 is connected to the collector of transistor PQ1; the positive terminal of diode PD4 is connected to the other end of resistor PR9; the negative terminal of diode PD4 is connected to the gate of MOSFET PM1; one end of resistor PR12 is connected to the positive terminal of diode PD4, and the other end is grounded. Through the above settings, the relay drive control circuit 500 can be stably operated to ensure reliable control of relay RY1.

[0040] like Figure 7As shown, in some embodiments of the battery management system, the relay control module further includes a transistor PQ3 and a Zener diode ZD2 in the relay drive control circuit 500. The emitter of transistor PQ3 is connected to the gate of MOSFET PM1, and the base of transistor PQ3 is connected to the collector of transistor PQ1. The collector of transistor PQ3 is grounded. One end of Zener diode ZD2 is connected to the gate of MOSFET PM1, and the other end is grounded. Specifically, the emitter of transistor PQ3 is connected between the cathode of diode PD4 and the gate of MOSFET PM1; the base of transistor PQ3 is connected to the anode of diode PD4; and the collector of transistor PQ3 is grounded after being connected in series with resistor R11. This embodiment improves the control responsiveness of relay RY1 through the above settings.

[0041] Benru Figure 2 and Figure 8 As shown, in some embodiments of the relay control module of the battery management system, the first step-down circuit 100 includes a step-down transformer VU2, capacitors VC3, VC7, VC12, VC2, and a Zener diode VZ1. The Vin pin of step-down transformer VU2 is connected to the positive terminal of the battery pack, and the GND pin of step-down transformer VU2 is grounded. One end of the parallel connection of capacitors VC3 and VC7 is connected to the Vin pin of step-down transformer VU2, and the other end is grounded. One end of the parallel connection of capacitors VC12, VC2, and Zener diode VZ1 is connected to the Vout pin of step-down transformer VU2, and the other end is grounded. The Vout pin of step-down transformer VU2 is provided with a VSYS node. Specifically, the VDD pin of the battery microprocessor LU1 is connected to the VSYS node, the other end of resistor VR25 is connected to the VSYS node, and the other end of resistor PR6 is connected to the VSYS node. Through the above configuration, this embodiment provides a stable operating voltage for the battery microprocessor LU1 and provides the required operating voltage for other circuits.

[0042] like Figure 2 and Figure 9 As shown, in some embodiments of the battery management system, the relay control module includes a pre-charge / discharge circuit 700 comprising a MOSFET PM3, a transistor PQ4, a transistor PQ6, a MOSFET MD1, a MOSFET MC1, a transistor PQ7, a transistor PQ5, and a MOSFET PM2.

[0043] The gate of MOSFET PM3 is connected to the DSG terminal of the battery microprocessor LU1 and the VSYS node, respectively. The gate of MOSFET PM3 is also grounded. The drain of MOSFET PM3 is connected to the base of transistor PQ4. The source of MOSFET PM3 is grounded. The base and emitter of transistor PQ4 are connected and then connected to the V14 node. The collector of transistor PQ4, the base of transistor PQ6, and the emitter of transistor PQ6 are connected and then grounded. The collector of transistor PQ6 is grounded. The gate of MOSFET MD1 is connected to the emitter of transistor PQ6. The source of MOSFET MD1 is connected to the SW1 pin of relay RY1. The drain of MOSFET MD1 is connected to... The drain of MOSFET MC1 is connected to the ground. The source of MOSFET MC1 is connected to the SW2 pin of relay RY1. The gate of MOSFET MC1 is connected to the emitter and base of transistor PQ7. The collector and base of transistor PQ7 are connected to the source of MOSFET MC1. The base of transistor PQ7 is connected to the collector of transistor PQ5. The emitter of transistor PQ5 is connected to node V14. The base of transistor PQ5 is connected to node V14 and the drain of MOSFET PM2. The source of MOSFET PM2 is grounded. The gate of MOSFET PM2 is connected to the CHG terminal of battery microprocessor LU1. The gate of MOSFET PM2 is also grounded.

[0044] In this embodiment, the output levels of the DSG and CHG terminals of the battery microprocessor LU1 are used to control the conduction states of MOSFETs PM3 and PM2, thereby controlling the conduction states of MOSFETs MD1 and MC1. This enables the on / off control of the pre-charge / discharge circuit 700, which helps to avoid relay arcing and extends the service life of the relay.

[0045] Specifically, such as Figure 9As shown, the gate of MOSFET PM3 is connected to the VSYS node after a series resistor PR16; the gate of MOSFET PM3 is grounded after a parallel resistor PR20 and capacitor PC4; the drain of MOSFET PM3 is connected to the base of transistor PQ4 after a series resistor PR15, and the base of transistor PQ4 is connected to the V14 node after a series resistor PR4; a diode PD3 is connected between the collector of transistor PQ4 and the emitter of transistor PQ6; the base of transistor PQ6 is grounded after a series resistor PR21; the emitter of transistor PQ6 is connected to the gate of MOSFET MD1 after a series resistor PR22, and a Zener diode ZD1 and resistor PR23 are connected in parallel between the gate and source of MOSFET MD1; a Zener diode ZD1 is connected in parallel between the gate and source of MOSFET MC1. Transistor ZD3 and resistor PR25; the source of MOSFET MC1 is connected to pin SW2 of relay RY1 via resistor PR26; diode PD6 is connected between the emitter and base of transistor PQ7, and the anode of diode PD6 is connected to the base of transistor PQ7; the base of transistor PQ7 is connected to the collector of transistor PQ7 via resistor PR24; the collector of transistor PQ5 is connected to the base of transistor PQ7 via resistor PR19 and diode PD5; resistor PR13 is connected between the base and emitter of transistor PQ5; resistor PR14 is connected between the base of transistor PQ5 and the drain of MOSFET PM2; the gate of MOSFET PM2 is connected to pin CHG of battery microprocessor LU1 via resistor PR17; and the gate of MOSFET PM2 is connected to ground via resistor PR18.

[0046] The above description is only a preferred embodiment of the present utility model. Therefore, any equivalent changes or modifications made to the structure, features and principles described in the claims of the present utility model patent application are included within the protection scope of the present utility model patent application.

Claims

1. A relay control module in a battery management system, characterized by, The first voltage reduction circuit and the second voltage reduction circuit are connected in parallel with the positive pole of the battery pack, the battery microprocessor is connected with the first voltage reduction circuit, the voltage adjustment circuit and the relay drive control circuit are connected with the second voltage reduction circuit and the battery microprocessor, and the current sampling circuit and the relay are connected in series with the negative pole of the battery pack; the current sampling circuit is also connected with the battery microprocessor.

2. The relay control module in a battery management system of claim 1, wherein, The second voltage reduction circuit comprises a voltage reducer VU1, a capacitor VC1, a resistor VR2, an inductor VL1, a capacitor VC6, a resistor VR4, a resistor VR10 and a resistor VR9; the voltage reducer VU1 is connected with the positive pole of the battery pack; one end of the series connection of the capacitor VC1, the resistor VR2 and the inductor VL1 is connected with the voltage reducer VU1, and the other end is connected with one end of the resistor VR9; the other end of the resistor VR9 is grounded; one end of the series connection of the resistor VR4 and the resistor VR10 is connected with one end of the resistor VR9, and the other end is grounded; the capacitor VC6 is connected with the resistor VR4 in parallel; the common end of the resistor VR4 and the resistor VR10 is connected with the voltage reducer VU1; the voltage adjustment circuit is connected with the common end of the resistor VR4 and the resistor VR10; one end of the resistor VR9 is provided with a V14 node.

3. The relay control module in a battery management system of claim 2, wherein, The second voltage reduction circuit further comprises a capacitor VC5, a capacitor VC8, a capacitor VC9 and a capacitor VC10; the capacitor VC5, the capacitor VC8, the capacitor VC9 and the capacitor VC10 are connected with the resistor VR9 in parallel respectively.

4. The relay control module in a battery management system of claim 2, wherein, The model of the voltage reducer VU1 is a voltage reduction converter MK9019.

5. The relay control module in a battery management system of claim 4, wherein, The second voltage reduction circuit further comprises a capacitor VC4, a voltage stabilizing diode VC1, a resistor VR3, a resistor VR14, a capacitor VC11 and a resistor VR15; the Vin pin of the voltage reducer VU1 is connected with the positive pole of the battery pack, the series connection of the EN pin of the voltage reducer VU1 and the resistor VR3 is connected with the Vin pin of the voltage reducer VU1; one end of the parallel connection of the capacitor VC4 and the voltage stabilizing diode VC1 is connected with the Vin pin of the voltage reducer VU1, and the other end is grounded; one end of the parallel connection of the resistor VR14 and the capacitor VC11 is connected with the EN pin of the voltage reducer VU1, and the other end is grounded; one end of the resistor VR15 is connected with the RT pin of the voltage reducer VU1, and the other end is grounded.

6. The relay control module in a battery management system of claim 1, wherein, The voltage adjustment circuit comprises a resistor VR12, a MOS tube VQ4, a resistor VR25 and a resistor VR38; the series connection of the drain of the MOS tube VQ4 and the resistor VR12 is connected with the second voltage reduction circuit; the source of the MOS tube VQ4 is grounded; one end of the resistor VR25 is connected with the gate of the MOS tube VQ4, and the other end is connected with the first voltage reduction circuit; one end of the resistor VR38 is connected with the gate of the MOS tube VQ4, and the other end is connected with the battery microprocessor.

7. The relay control module in a battery management system of claim 1, wherein, The relay drive control circuit comprises a transistor PQ1, a transistor PQ2, a MOS PM1 and a bidirectional breakdown diode TVS1; the emitter of the transistor PQ1 is connected with the second voltage reduction circuit, the base of the transistor PQ1 is connected with the collector of the transistor PQ2, and the collector of the transistor PQ1 is connected with the gate of the MOS PM1; the base of the transistor PQ2 is connected with the battery microprocessor, and the emitter of the transistor PQ2 is grounded; the source of the MOS PM1 is grounded; one end of the bidirectional breakdown diode TVS1 is connected with the second voltage reduction circuit, and the other end is connected with the drain of the MOS PM1; the two ends of the bidirectional breakdown diode TVS1 are also connected with the relay.

8. The relay control module in a battery management system of claim 7, wherein, The relay drive control circuit further comprises a transistor PQ3 and a voltage stabilizing diode ZD2; the emitter of the transistor PQ3 is connected with the gate of the MOS PM1, the base of the transistor PQ3 is connected with the collector of the transistor PQ1, and the collector of the transistor PQ3 is grounded; one end of the voltage stabilizing diode ZD2 is connected with the gate of the MOS PM1, and the other end is grounded.

9. The relay control module in a battery management system of claim 1, wherein, The first voltage reduction circuit comprises a voltage reducer VU2, a capacitor VC3, a capacitor VC7, a capacitor VC12, a capacitor VC2 and a voltage stabilizing diode VZ1; the Vin pin of the voltage reducer VU2 is connected with the positive pole of the battery pack, the GND pin of the voltage reducer VU2 is grounded, one end of the parallel connection of the capacitor VC3 and the capacitor VC7 is connected with the Vin pin of the voltage reducer VU2, and the other end is grounded; one end of the parallel connection of the capacitor VC12, the capacitor VC2 and the voltage stabilizing diode VZ1 is connected with the Vout pin of the voltage reducer VU2, and the other end is grounded; the Vout pin of the voltage reducer VU2 is provided with a VSYS node.

10. The relay control module in a battery management system according to any one of claims 1 to 9, characterized in that, The pre-charge and discharge circuit in parallel with the relay is further provided; the pre-charge and discharge circuit is connected with the battery microprocessor.

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