Charging and discharging control circuit of BMS

Abstract

The utility model discloses a charging and discharging control circuit of a BMS. The charging and discharging control circuit is connected with an MCU, a charging and discharging MOS switch, a single battery and a charger. Comprising an AFE chip U17, a discharging driving module (100), a charging driving module (200), a charging rapid turn-off module (300) and a voltage acquisition module (400). The AFE chip U17 is connected with a discharge driving module (100), a charge driving module (200), a charge quick turn-off module (300) and a voltage acquisition module (400); the discharging driving module (100), the charging driving module (200) and the charging rapid turn-off module (300) are connected with a charging and discharging MOS switch. The voltage acquisition module (400) is connected with a single battery; and the charging quick turn-off module (300) is connected with the negative electrode of the charger. According to the utility model, the charging and discharging turn-off control response speed is fast, the safety is high, and the stability is high.

Description

TECHNICAL FIELD

[0001] The utility model relates to BMS technical field, concretely is a kind of BMS's charge-discharge control circuit. BACKGROUND

[0002] BMS (Battery Management System, battery management system) is a kind of system for monitoring battery state information, and control battery charge-discharge;BMS not only can protect the safe operation of battery, but also can effectively prolong its service life, improve the utilization efficiency of energy. The control of existing BMS to battery charge-discharge process is generally through chip acquisition battery state information, and output control signal, control the conduction or turn-off of charge-discharge MOS switch on charge-discharge loop to realize. But the conduction of charge-discharge MOS switch usually needs larger voltage, and the control signal of chip output generally cannot directly satisfy such large voltage, so it needs chip to connect driving module to control charge-discharge MOS switch. The response speed of existing BMS to battery charge-discharge control is influenced by driving module;Driving module needs circuit to be able to run smoothly, so it will have certain limit to its response speed, if the level in driving module changes rapidly, some circuit components are prone to damage. But especially in battery charging process, when battery is in abnormal state such as voltage is too large, if charging loop cannot be disconnected in first time, battery is heated, and battery is prone to damage even fire;Therefore, charge-discharge MOS switch needs to be able to turn off quickly. SUMMARY

[0003] The utility model aims at providing a kind of BMS's charge-discharge control circuit. The charge-discharge turn-off control response speed of the utility model is fast, with the advantages of strong safety, high stability.

[0004] The technical scheme of the utility model: a kind of BMS's charge-discharge control circuit, respectively connect MCU, charge-discharge MOS switch, single battery and charger;Including AFE chip U17, discharge driving module, charging driving module, charging quick turn-off module and voltage acquisition module;AFE chip U17 is connected discharge driving module, charging driving module, charging quick turn-off module and voltage acquisition module;Discharge driving module, charging driving module, charging quick turn-off module connect charge-discharge MOS switch;Voltage acquisition module connects single battery;Charging quick turn-off module connects charger negative pole.

[0005] The charge-discharge control circuit of the BMS, the discharge driving module comprises a diode D63, a diode D64, a diode D65, a resistor R302, a resistor R308, a resistor R311, a capacitor C121, a capacitor C122 and a chip U18; the ENA pin of the chip U18 is connected with one end of the resistor R302 and the negative electrode of the diode D65; the other end of the resistor R302 is grounded; the positive electrode of the diode D65 is connected with the MCU; the INA pin of the chip U18 is connected with one end of the resistor R308, and the other end of the resistor R308 is connected with the AFE chip U17; the GND pin of the chip U18 is grounded; the INB pin of the chip U18 is connected with one end of the resistor R311, and the other end of the resistor R311 is connected with the MCU; the ENB pin of the chip U18 is connected with the negative electrode of the diode D64, the VDD pin of the chip U18, one end of the capacitor C121 and one end of the capacitor C122; the other end of the capacitor C121 is connected with the other end of the capacitor C122 and grounded; the positive electrode of the diode D64 is connected with the positive electrode of the diode D63 and connected with a 13V voltage source; the negative electrode of the diode D63 is connected with a 12V voltage source; the OUTA pin of the chip U18 is connected with the charge-discharge MOS switch; and the OUTB pin of the chip U18 is connected with the pre-charge module.

[0006] The charge-discharge control circuit of the BMS, the charge driving module comprises a MOS Q46, a MOS Q49, a resistor R274, a resistor R277, a resistor R279, a resistor R280, a resistor R287 and a diode D60; one end of the resistor R280 is connected with the AFE chip U17; the other end of the resistor R280 is connected with one end of the resistor R287 and the gate of the MOS Q49; the other end of the resistor R287 is connected with the source of the MOS Q49 and grounded; the drain of the MOS Q49 is connected with one end of the resistor R279; the other end of the resistor R279 is connected with one end of the resistor R277 and the gate of the MOS Q46; the other end of the resistor R277 is connected with the source of the MOS Q46 and a 12V voltage source; the drain of the MOS Q46 is connected with the positive electrode of the diode D60; one end of the resistor R274 is connected with the negative electrode of the diode D60; the other end of the resistor R274 is connected with the charge-discharge MOS switch.

[0007] The charge and discharge control circuit of the BMS, the charge fast-off module comprises MOS Q45, MOS Q48, MOS Q50, resistor R275, resistor R276, resistor R278, resistor R281, resistor R284, resistor R285, resistor R289, resistor R290 and diode D61; one end of the resistor R281 is connected with the AFE chip U17; the other end of the resistor R281 is connected with one end of the resistor R290 and the gate of the MOS Q50; the other end of the resistor R290 is connected with the source of the MOS Q50, one end of the resistor R285 and the source of the MOS Q48, and grounded; the drain of the MOS Q50 is connected with one end of the resistor R275 and one end of the resistor R278; the other end of the resistor R278 is connected with the other end of the resistor R285 and the gate of the MOS Q48; the drain of the MOS Q48 is connected with one end of the resistor R276 and the gate of the MOS Q45; the other end of the resistor R275 is connected with the other end of the resistor R276 and the source of the MOS Q45, and connected with a 12V voltage source; the drain of the MOS Q45 is connected with the positive electrode of the diode D61; the negative electrode of the diode D61 is connected with one end of the resistor R284; the other end of the resistor R284 is connected with the gate of the MOS Q47 and one end of the resistor R289; the other end of the resistor R289 is connected with the source of the MOS Q47, and connected with the negative electrode of the charger; the drain of the MOS Q47 is connected with the charge and discharge MOS switch.

[0008] The charge and discharge control circuit of the BMS, the voltage acquisition module comprises a plurality of voltage acquisition subunits, the voltage acquisition subunits are connected in parallel, and the voltage acquisition subunits are connected with the AFE chip U17; the voltage acquisition subunit comprises resistor R213, resistor R214, resistor R215, resistor R216, triode Q35, capacitor C102 and diode D44; one end of the resistor R214 is connected with one end of the resistor R213, and connected with a single battery; the other end of the resistor R214 is connected with the collector of the triode Q35; the other end of the resistor R213 is connected with one end of the capacitor C102, the negative electrode of the diode D44 and the AFE chip U17; the base of the triode Q35 is connected with one end of the resistor R215; the emitter of the triode Q35 is connected with one end of the resistor R216; the other end of the resistor R215 is connected with the other end of the resistor R216, the other end of the capacitor C102, the positive electrode of the diode D44 and the AFE chip U17.

[0009] The charge and discharge control circuit of the BMS, the model of the AFE chip U17 is SH367309.

[0010] The charge and discharge control circuit of the BMS, the model of the chip U18 is SCT52240.

[0011] Compared with the prior art, the AFE chip U17 collects the voltage of the single battery through the voltage acquisition module, and outputs a charge-discharge control signal to the discharge driving module, the charge driving module and the charge fast-off module; the discharge driving module and the charge driving module are used for driving control of the fast conduction or off of the charge-discharge MOS switch, so as to realize the fast conduction or off of the charge-discharge loop; the charge fast-off module is turned on by receiving the opposite level signal of the charge driving module, and directly pulls down the conduction signal of the charge loop to the negative pole of the charger, so as to quickly turn off the charge loop; the charge-discharge off control of the utility model has the advantages of fast response speed, high safety and high stability. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is the circuit diagram of the utility model;

[0013] Figure 2 is the circuit diagram of the discharge driving module;

[0014] Figure 3 is the circuit diagram of the charge driving module and the charge fast-off module;

[0015] Figure 4 is the circuit diagram of the voltage acquisition module.

[0016] The marks in the drawings are: 100-discharge driving module, 200-charge driving module, 300-charge fast-off module, 400-voltage acquisition module, 410-voltage acquisition subunit. DETAILED DESCRIPTION

[0017] The utility model will be further described below in combination with the drawings and examples, but not as the basis for limiting the utility model.

[0018] Example: the charge-discharge control circuit of BMS is connected with MCU, charge-discharge MOS switch, single battery and charger respectively; as Figure 1As shown, including AFE chip U17, discharge drive module 100, charging drive module 200, charging fast-off module 300 and voltage acquisition module 400;The model of the AFE chip U17 is SH367309.The AFE chip U17 is connected discharge drive module 100, charging drive module 200, charging fast-off module 300 and voltage acquisition module 400;The discharge drive module 100, charging drive module 200, charging fast-off module 300 are connected to charge-discharge MOS switch;The voltage acquisition module 400 is connected to single battery;The charging fast-off module 300 is connected to charger negative pole.The AFE chip U17 of the utility model acquires the voltage of single battery through voltage acquisition module 400, and exports charge-discharge control signal to discharge drive module 100, charging drive module 200 and charging fast-off module 300;The discharge drive module 100 and charging drive module 200 are used to drive control the fast conduction or off of charge-discharge MOS switch, realize the fast conduction or off of charge-discharge loop;The charging fast-off module 300 is conducted through receiving the opposite level signal of charging drive module 200, and directly pulls down the conduction signal of charging loop to charger negative pole, can fast-off charging loop;The charge-discharge control of the utility model has the advantages of fast response speed, strong safety, high stability.

[0019] Discharge drive module 100 as Figure 2As shown, the discharge driving module 100 includes a diode D63, a diode D64, a diode D65, a resistor R302, a resistor R308, a resistor R311, a capacitor C121, a capacitor C122 and a chip U18; an ENA pin of the chip U18 is connected with one end of the resistor R302 and a negative electrode of the diode D65; the other end of the resistor R302 is grounded; a positive electrode of the diode D65 is connected with the MCU; an INA pin of the chip U18 is connected with one end of the resistor R308, and the other end of the resistor R308 is connected with the AFE chip U17; a GND pin of the chip U18 is grounded; an INB pin of the chip U18 is connected with one end of the resistor R311, and the other end of the resistor R311 is connected with the MCU; an ENB pin of the chip U18 is connected with a negative electrode of the diode D64, a VDD pin of the chip U18, one end of the capacitor C121 and one end of the capacitor C122; the other end of the capacitor C121 is connected with the other end of the capacitor C122 and grounded; a positive electrode of the diode D64 is connected with a positive electrode of the diode D63 and connected with a 13V voltage source; a negative electrode of the diode D63 is connected with a 12V voltage source; an OUTA pin of the chip U18 is connected with the charge-discharge MOS switch; and an OUTB pin of the chip U18 is connected with the pre-charge module. The discharge driving module 100 receives control signals from the AFE chip U17 and the MCU through the chip U18; when the AFE chip U17 sends a discharge signal to the chip U18 through the resistor R308, an OUTA pin of the chip U18 outputs a high-level signal, so that the discharge MOS tube is opened, the discharge circuit is turned on, and the battery is discharged; when the MCU sends a pre-charge control signal to the chip U18 through the resistor R311, an OUTB pin of the chip U18 outputs a control signal to the pre-charge module, so that the pre-charge module works; the pre-charge module is realized by a capacitor, a pre-charge resistor and a pre-charge relay; when the pre-charge module works, the pre-charge relay is first closed, and the battery charges the capacitor through the pre-charge resistor; when the voltage of the capacitor approaches the voltage of the battery, the pre-charge relay is disconnected, and the pre-charge process is completed; in this way, it can be ensured that the capacitor has a certain amount of electric charge when the power is formally turned on, thereby avoiding the generation of instantaneous large current. The pre-charge module can reduce the current impact when the battery is discharged, thereby prolonging the service life of the battery and the load. The model of the chip U18 is SCT52240, which is a double-channel driving chip with a maximum driving / drainage current of 4A; the input signal of the chip U18 can be quickly transmitted to the output end, so that the discharge MOS tube is driven through the chip U18, which can make the on and off time of the discharge MOS tube more rapid, and has the advantage of fast response.

[0020] The charge driving module 200 is as shown in the following table: Figure 3As shown, the charging drive module 200 includes MOS Q46, MOS Q49, resistor R274, resistor R277, resistor R279, resistor R280, resistor R287 and diode D60; one end of the resistor R280 is connected to the AFE chip U17; the other end of the resistor R280 is connected to one end of the resistor R287 and the gate of the MOS Q49; the other end of the resistor R287 is connected to the source of the MOS Q49 and grounded; the drain of the MOS Q49 is connected to one end of the resistor R279; the other end of the resistor R279 is connected to one end of the resistor R277 and the gate of the MOS Q46; the other end of the resistor R277 is connected to the source of the MOS Q46 and a 12V voltage source; the drain of the MOS Q46 is connected to the positive electrode of the diode D60; one end of the resistor R274 is connected to the negative electrode of the diode D60; the other end of the resistor R274 is connected to the charge-discharge MOS switch. When the AFE chip U17 sends a high-level signal to the charging drive module 200, the gate of the MOS Q49 receives a high-level signal through the resistor R280 and turns on, the gate voltage of the MOS Q46 is pulled low to the ground by the resistor R279, and the MOS Q46 turns on, thereby the charging drive module 200 sends a high-level drive signal to the charging MOS, so that the charging MOS turns on, the charging loop is turned on, and the battery is charged; conversely, when the AFE chip U17 sends a low-level signal to the charging drive module 200, the charging drive module 200 sends a low-level signal to the charging MOS, the charging MOS turns off, and the charging loop turns off.

[0021] The charging fast-off module 300 is as shown in Figure 3As shown, the fast charge-off module 300 comprises MOS Q45, MOS Q48, MOS Q50, resistor R275, resistor R276, resistor R278, resistor R281, resistor R284, resistor R285, resistor R289, resistor R290 and diode D61; one end of the resistor R281 is connected to the AFE chip U17; the other end of the resistor R281 is connected to one end of the resistor R290 and the gate of the MOS Q50; the other end of the resistor R290 is connected to the source of the MOS Q50, one end of the resistor R285 and the source of the MOS Q48, and is grounded; the drain of the MOS Q50 is connected to one end of the resistor R275 and one end of the resistor R278; the other end of the resistor R278 is connected to the other end of the resistor R285 and the gate of the MOS Q48; the drain of the MOS Q48 is connected to one end of the resistor R276 and the gate of the MOS Q45; the other end of the resistor R275 is connected to the other end of the resistor R276 and the source of the MOS Q45, and is connected to a 12V voltage source; the drain of the MOS Q45 is connected to the positive electrode of the diode D61; the negative electrode of the diode D61 is connected to one end of the resistor R284; the other end of the resistor R284 is connected to the gate of the MOS Q47 and one end of the resistor R289; the other end of the resistor R289 is connected to the source of the MOS Q47, and is connected to the negative electrode of the charger; the drain of the MOS Q47 is connected to the charge-discharge MOS switch. The fast charge-off module 300 and the charge drive module 200 share the same signal input end and signal output end; when the AFE chip U17 sends a high-level signal to the fast charge-off module 300, the MOS Q50 is turned on through the resistor R281, the gate voltage of the MOS Q48 is pulled down to the ground, the MOS Q48 is turned off, the gate voltage of the MOS Q45 is pulled up through the resistor R276, the MOS Q45 is turned off, the gate voltage of the MOS Q47 is low, the MOS Q47 is turned off, the charging MOS is turned on by the high-level signal output by the charge drive module 200, and the battery is charged. When the AFE chip U17 sends a low-level signal to the fast charge-off module 300, the MOS Q50 is turned off, the gate voltage of the MOS Q48 is pulled up by the resistor R275 and the resistor R278, the MOS Q48 is turned on, the gate voltage of the MOS Q45 is pulled down to the ground, the MOS Q45 is turned on, the gate of the MOS Q47 is high through the diode D61 and the resistor R284, the MOS Q47 is turned on, the signal output end of the fast charge-off module 300 is pulled down to the negative electrode of the charger, the charging MOS is quickly turned off, and the charging circuit is quickly turned off; thus, the battery charging process can be quickly turned off, and the battery is protected.

[0022] The voltage collection module 400 is as shown in FIG. 4. Figure 4As shown, the voltage acquisition module 400 includes a plurality of voltage acquisition subunits 410, which are connected in parallel, and the voltage acquisition subunits 410 are respectively connected to the AFE chip U17; the voltage acquisition subunit 410 includes resistors R213, R214, R215, R216, a transistor Q35, a capacitor C102, and a diode D44; one end of the resistor R214 is connected to one end of the resistor R213 and to the single battery; the other end of the resistor R214 is connected to the collector of the transistor Q35; the other end of the resistor R213 is connected to one end of the capacitor C102, the negative electrode of the diode D44, and the AFE chip U17; the base of the transistor Q35 is connected to one end of the resistor R215; the emitter of the transistor Q35 is connected to one end of the resistor R216; the other end of the resistor R215 is connected to the other end of the resistor R216, the other end of the capacitor C102, the positive electrode of the diode D44, and the AFE chip U17. The voltage acquisition subunit 410 of the voltage acquisition module 400 is used to acquire the voltage information of the single battery and transmit the voltage information to the AFE chip U17, supports 5-16 string single battery acquisition; at the same time, the AFE chip U17 supports the passive equalization function through the voltage acquisition module 400, supports 8-way simultaneous equalization, and the equalization current is greater than 50mA.

[0023] In addition, the AFE chip U17 of the utility model is also connected with a current acquisition module, such as Figure 4 As shown, including resistors R232, R233, a capacitor C107, a capacitor C109, and a capacitor C110; the current acquisition module is used to acquire the current information when the battery charges and discharges, and transmit it to the AFE chip U17, the sampling accuracy is 16-bit, and the current error is less than 2%; and the current acquisition module plays a monitoring role on the charging and discharging current of the battery.

[0024] Working principle: the AFE chip U17 of the utility model acquires the voltage of the single battery through the voltage acquisition module 400, and outputs a charging and discharging control signal to the discharging driving module 100, the charging driving module 200, and the charging fast-off module 300; the discharging driving module 100 and the charging driving module 200 are used to drive and control the fast conduction or turn-off of the charging and discharging MOS switch, realize the fast conduction or turn-off of the charging and discharging loop; the charging fast-off module 300 is turned on by receiving a level signal opposite to the charging driving module 200, and directly pulls down the conduction signal of the charging loop to the negative electrode of the charger, so that the charging loop can be quickly turned off; the charging and discharging control of the utility model has the advantages of fast response speed, high safety, and high stability.

[0025] The above embodiment only expresses the implementation mode of the utility model, and the description is relatively specific and detailed, but cannot be understood as the limitation of the utility model patent range, and in the embodiment, up, down, left, right, front and back only represent relative positions and do not represent absolute positions. It should be pointed out 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 charge-discharge control circuit of a BMS, connected with an MCU, a charge-discharge MOS switch, a single battery and a charger respectively; characterized in that: It includes AFE chip U17, discharge driving module (100), charging driving module (200), charging fast-off module (300) and voltage acquisition module (400); the AFE chip U17 is connected with discharge driving module (100), charging driving module (200), charging fast-off module (300) and voltage acquisition module (400); discharge driving module (100), charging driving module (200) and charging fast-off module (300) are connected with charge-discharge MOS switch; the voltage acquisition module (400) is connected with single battery; The charging fast-off module (300) is connected with the negative electrode of the charger.

2. The charge and discharge control circuit of the BMS according to claim 1, characterized in that: The discharge driving module (100) includes diode D63, diode D64, diode D65, resistor R302, resistor R308, resistor R311, capacitor C121, capacitor C122 and chip U18; the ENA pin of the chip U18 is connected with one end of the resistor R302 and the negative electrode of the diode D65; the other end of the resistor R302 is grounded; the positive electrode of the diode D65 is connected with MCU; the INA pin of the chip U18 is connected with one end of the resistor R308, and the other end of the resistor R308 is connected with the AFE chip U17; the GND pin of the chip U18 is grounded; the INB pin of the chip U18 is connected with one end of the resistor R311, and the other end of the resistor R311 is connected with MCU; the ENB pin of the chip U18 is connected with the negative electrode of the diode D64, the VDD pin of the chip U18, one end of the capacitor C121 and one end of the capacitor C122; the other end of the capacitor C121 is connected with the other end of the capacitor C122 and grounded; the positive electrode of the diode D64 is connected with the positive electrode of the diode D63 and connected with 13V voltage source; the negative electrode of the diode D63 is connected with 12V voltage source; the OUTA pin of the chip U18 is connected with the charge-discharge MOS switch; the OUTB pin of the chip U18 is connected with pre-charge module.

3. The charge and discharge control circuit of the BMS according to claim 1, characterized in that: The charging driving module (200) includes MOS tube Q46, MOS tube Q49, resistor R274, resistor R277, resistor R279, resistor R280, resistor R287 and diode D60; one end of the resistor R280 is connected with the AFE chip U17; the other end of the resistor R280 is connected with one end of the resistor R287 and the gate of the MOS tube Q49; the other end of the resistor R287 is connected with the source of the MOS tube Q49 and grounded; the drain of the MOS tube Q49 is connected with one end of the resistor R279; the other end of the resistor R279 is connected with one end of the resistor R277 and the gate of the MOS tube Q46; the other end of the resistor R277 is connected with the source of the MOS tube Q46 and connected with 12V voltage source; the drain of the MOS tube Q46 is connected with the positive electrode of the diode D60; one end of the resistor R274 is connected with the negative electrode of the diode D60; the other end of the resistor R274 is connected with the charge-discharge MOS switch.

4. The charge and discharge control circuit of the BMS according to claim 3, characterized in that: The charging fast-off module (300) comprises MOS tube Q45, MOS tube Q48, MOS tube Q50, resistor R275, resistor R276, resistor R278, resistor R281, resistor R284, resistor R285, resistor R289, resistor R290 and diode D61; one end of the resistor R281 is connected with the AFE chip U17; the other end of the resistor R281 is connected with one end of the resistor R290 and the gate of the MOS tube Q50; the other end of the resistor R290 is connected with the source of the MOS tube Q50, one end of the resistor R285 and the source of the MOS tube Q48, and is grounded; the drain of the MOS tube Q50 is connected with one end of the resistor R275 and one end of the resistor R278; the other end of the resistor R278 is connected with the other end of the resistor R285 and the gate of the MOS tube Q48; the drain of the MOS tube Q48 is connected with one end of the resistor R276 and the gate of the MOS tube Q45; the other end of the resistor R275 is connected with the other end of the resistor R276 and the source of the MOS tube Q45, and is connected with a 12V voltage source; the drain of the MOS tube Q45 is connected with the anode of the diode D61; the cathode of the diode D61 is connected with one end of the resistor R284; the other end of the resistor R284 is connected with the gate of the MOS tube Q47 and one end of the resistor R289; the other end of the resistor R289 is connected with the source of the MOS tube Q47, and is connected with the negative electrode of the charger; the drain of the MOS tube Q47 is connected with the charge-discharge MOS switch.

5. The charge and discharge control circuit of the BMS according to claim 1, characterized in that: The voltage acquisition module (400) comprises a plurality of voltage acquisition subunits (410), which are connected in parallel; the voltage acquisition subunits (410) are connected with the AFE chip U17 respectively; the voltage acquisition subunit (410) comprises resistor R213, resistor R214, resistor R215, resistor R216, triode Q35, capacitor C102 and diode D44; one end of the resistor R214 is connected with one end of the resistor R213, and is connected with a single battery; the other end of the resistor R214 is connected with the collector of the triode Q35; the other end of the resistor R213 is connected with one end of the capacitor C102, the cathode of the diode D44 and the AFE chip U17; the base of the triode Q35 is connected with one end of the resistor R215; the emitter of the triode Q35 is connected with one end of the resistor R216; the other end of the resistor R215 is connected with the other end of the resistor R216, the other end of the capacitor C102, the anode of the diode D44 and the AFE chip U17.

6. The charge and discharge control circuit of the BMS according to claim 1, wherein: The model of the AFE chip U17 is SH367309.

7. The charge and discharge control circuit of the BMS according to claim 2, characterized by: The model of the chip U18 is SCT52240.

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