A pre-charge pre-discharge control circuit for a battery system

Abstract

The utility model discloses a kind of pre-charge pre-discharge control circuits of battery system, including pre-charge control module, pre-discharge control module, protection module, resistance module, first relay module, second relay module and load capacitor;The output end of pre-charge control module is connected with protection module, pre-charge control module is also connected with pre-discharge control module, and pre-charge control module and pre-discharge control module interlock;Protection module is connected with battery positive connection end, pre-discharge control module and resistance module respectively;Battery negative connection end is grounded;First relay module and second relay module are connected with resistance module respectively, and first relay module and second relay module are connected in series, and load capacitor is connected with second relay module.

Description

Technical Field

[0001] This utility model relates to the field of precharge and pre-discharge circuit technology, specifically to a precharge and pre-discharge control circuit for a battery system. Background Technology

[0002] With the development of high-voltage electrical equipment such as new energy vehicles and energy storage systems, the safety and reliability of high-voltage battery management systems (BMS) are receiving increasing attention. In high-voltage BMS, the pre-charge circuit is a key component in the startup process. It is used to slowly charge the load capacitor through a current-limiting resistor before the main circuit is connected, so as to avoid damage to relays or load equipment due to instantaneous large current surges.

[0003] Existing pre-charging circuits such as Figure 1 As shown, before system startup, the pre-charge relay charges the load capacitor through the pre-charge resistor. When the load capacitor voltage is detected to be close to the battery voltage, the main positive relay closes, and the system enters normal power supply mode. When the system stops working, the main positive relay opens, and the system enters standby mode.

[0004] However, in the traditional solution described above, high-voltage energy may still remain in the load capacitor after the system is shut down. Without proper safety discharge, this could pose a risk of electric shock to maintenance personnel or equipment. Furthermore, the traditional solution does not provide an independent pre-discharge circuit or discharge path, which is detrimental to safe system maintenance. Utility Model Content

[0005] To address the shortcomings of existing technologies, a precharge and pre-discharge control circuit for a battery system is provided.

[0006] To achieve the above objectives, this utility model provides a precharge and pre-discharge control circuit for a battery system, which has a positive battery connection terminal and a negative battery connection terminal, including a precharge control module, a pre-discharge control module, a protection module, a resistor module, a first relay module, a second relay module, and a load capacitor; the output terminal of the precharge control module is connected to the protection module, and the precharge control module is also connected to the pre-discharge control module, and the precharge control module and the pre-discharge control module are interlocked; the protection module is connected to the positive battery connection terminal, the pre-discharge control module, and the resistor module respectively; the negative battery connection terminal is grounded; the first relay module and the second relay module are respectively connected to the resistor module, and the first relay module and the second relay module are connected in series, and the load capacitor is connected to the second relay module.

[0007] According to one embodiment of the present invention, the precharge control module includes a control chip U1, a MOSFET Q24, and a MOSFET Q15. The control chip U1 has an input terminal and an output terminal. The gate of the MOSFET Q24 is connected to the input terminal of the control chip U1, and its source is grounded together with the input terminal of the control chip U1. The drain of the MOSFET Q24 is connected to the pre-amplification control module. The output terminal of the control chip U1 is connected to the pre-amplification control module and the gate of the MOSFET Q15. The source of the MOSFET Q15 is grounded, and the drain of the MOSFET Q15 is connected to the protection module.

[0008] According to one embodiment of the present invention, the protection module includes a MOSFET Q16, a Zener diode Z20, a MOSFET Q17, and a fuse assembly; the gate of the MOSFET Q16 is connected to the precharge control module, and the drain of the MOSFET Q16 is connected to the positive terminal of the battery; the source of the MOSFET Q16 is connected to the negative terminal of the Zener diode Z20 and the source of the MOSFET Q7, respectively; the positive terminal of the Zener diode Z20 is connected to the precharge control module, the gate of the MOSFET Q16, and the gate of the MOSFET Q17, respectively; the drain of the MOSFET Q17 is connected to one end of the fuse assembly, and the other end of the fuse assembly is connected to the pre-discharge control module and the resistor module, respectively.

[0009] According to one embodiment of the present invention, the pre-amplification control module includes a control chip U2, a MOSFET Q22, and a MOSFET Q12. The control chip U2 has an input terminal and an output terminal. The input terminal is connected to the gate of the MOSFET Q22, and the output terminal of the control chip U2 is connected to the gate of the MOSFET Q12 and the drain of the MOSFET Q24. The drain of the MOSFET Q22 is connected to the output terminal of the control chip U1 and the gate of the MOSFET Q15, and the source of the MOSFET Q22 is grounded. The drain of the MOSFET Q12 is connected to the protection module and the resistor module, and the source of the MOSFET Q12 is grounded.

[0010] According to one embodiment of the present invention, the first relay module includes a first relay, a first RC unit, and a first control unit; the first relay has a first switch terminal, a second switch terminal, a first coil terminal, and a second coil terminal; the first switch terminal of the first relay is connected to the positive connection terminal of the battery, the second switch terminal is connected to the first RC unit and the resistor module respectively, the first coil terminal of the first relay is connected to the power supply voltage, and its second coil terminal is connected to the first control unit.

[0011] According to one embodiment of the present invention, the second relay module includes a second relay, a second RC unit, and a second control unit; the second relay has a third switch terminal, a fourth switch terminal, a third coil terminal, and a fourth coil terminal, the third switch terminal is connected to the resistor module and the second switch terminal respectively, the fourth switch terminal is connected to the second RC unit and the load capacitor, the third coil terminal is connected to the power supply voltage, and the fourth coil terminal is connected to the second control unit.

[0012] According to one embodiment of the present invention, the first filter unit includes resistor R265, resistor R266, resistor R174 and capacitor C262. One end of resistor R265 is connected to the resistor module and the second switch terminal, and the other end is connected to resistor R174 and resistor R266 respectively. One end of resistor R266 is connected to capacitor C262, and the other end of capacitor C262 is grounded together with resistor R174.

[0013] According to one embodiment of the present invention, the first control unit includes a MOSFET Q13, a resistor R128 and a resistor R267. The gate of the MOSFET Q13 is connected to the resistors R128 and R267 respectively. The other end of the resistor R267 is grounded together with the source of the MOSFET Q13. The drain of the MOSFET Q13 is connected to the power supply voltage and the first coil terminal.

[0014] According to one embodiment of the present invention, the protection module further includes a Zener diode Z19, the negative terminal of which is connected to the drain positive terminal of the MOSFET Q16, and the negative terminal is connected to the negative terminal of the battery and the ground terminal.

[0015] According to one embodiment of the present invention, it further includes a diode D9, the negative terminal of which is connected to the first coil terminal and the power supply voltage, and its positive terminal is connected to the first control unit and the second control unit.

[0016] The beneficial effect of this utility model is that, when the battery system stops, by controlling the pre-discharge control module to be on, the second relay module to be on, and the first relay module to be off, the discharge electrical signal of the load capacitor passes through the second relay module, then through the resistor module, and finally through the pre-discharge control module to be output to the ground, thereby discharging the load capacitor. When the host computer detects that the load capacitor has finished discharging, the host computer sends a low-level signal to the pre-discharge control module, causing the pre-discharge control module to be off, thus breaking the discharge path of the load capacitor and stopping the load capacitor from discharging. By setting the pre-discharge control module, the voltage in the load capacitor is released after the battery system stops, preventing the voltage in the load capacitor from damaging the equipment. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A pre-charging roadmap for existing technologies; Figure 2 This is a circuit diagram of the precharge and pre-discharge control circuit of the battery system in the embodiment.

[0018] Explanation of reference numerals in the attached figures 1. Precharge control module; 2. Pre-discharge control module; 3. Protection module; 31. Fuse assembly; 4. Resistor module; 5. First relay module; 51. First relay; 52. First RC unit; 53. First control unit; 6. Second relay module; 61. Second relay; 62. Second RC unit; 63. Second control unit; 7. Load capacitor. Detailed Implementation

[0019] The following drawings will disclose several embodiments of this utility model. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this utility model. That is, in some embodiments of this utility model, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0020] Furthermore, in this utility model, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the utility model. They are merely used to distinguish components or operations described with the same technical terms and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0021] Please refer to Figure 2 , Figure 2 This is a circuit diagram of a precharge and pre-discharge control system for a battery system. This embodiment provides a precharge and pre-discharge control circuit for a battery system, having a positive terminal connection and a negative terminal connection. The precharge and pre-discharge control circuit includes a precharge control module 1, a pre-discharge control module 2, a protection module 3, a resistor module 4, a first relay module 5, a second relay module 6, and a load capacitor 7. The output terminal of the precharge control module 1 is connected to the protection module 3. The precharge control module 1 is also connected to the pre-discharge control module 2, and the precharge control module 1 and the pre-discharge control module 2 are interlocked. The protection module 3 is connected to both the pre-discharge control module 2 and the resistor module 4. The first relay module 5 and the second relay module 6 are connected to the resistor module 4, and are connected in series. The load capacitor 7 is connected to the second relay module 6.

[0022] In practical use, the positive connection terminal of the battery is used to connect to the positive terminal of the battery, and the negative connection terminal is grounded. The input terminal of the precharge control module 1 is connected to the host computer, which is connected to the input terminal of the precharge control module 1, the input terminal of the pre-discharge control module 2, the first relay module 5, and the second relay module 6. The second relay module 6 is also connected to the load capacitor 7 and the load motor.

[0023] When the host computer sends a precharge signal to the precharge and pre-discharge control circuit of the battery system, a high-level signal is input to the input terminal of the precharge control module 1. Simultaneously, the host computer sends a low-level signal to the first relay module 5 and a high-level signal to the second relay module 6. The precharge control module 1 conducts upon receiving the high-level signal. After conducting, the precharge control module 1 outputs a low-level signal to the protection module 3. At the same time, it outputs a low-level signal to the pre-discharge control module 2. Upon receiving the low-level signal, the pre-discharge control module 2 is turned off. Thus, when the precharge control module 1 is on, the pre-discharge control module 2 is off, preventing the protection module 3 and the pre-discharge control unit from operating simultaneously, achieving an interlocking effect. The protection module 3 conducts upon receiving the low-level signal. At this time, the electrical signal output by the battery passes through the protection module 3 and is input to the resistor module 4. Then, the electrical signal passes through the resistor module 4 and is input to the first relay module 5 and the second relay module 6, energizing them. The first relay module 5 disconnects upon receiving a low-level signal, and the second relay module 6 closes upon receiving a high-level signal. After the second relay module 6 closes, the electrical signal is input to the load capacitor 7 through the second relay module 6, charging the load capacitor 7.

[0024] The host computer continuously monitors the voltage of the load capacitor 7. When the voltage of the load capacitor 7 equals the battery voltage, pre-charging is complete. Then, the host computer sends a low-level signal to the input of the pre-charging control module 1, causing the pre-charging control module 1 to shut down, thereby cutting off the protection module 3. The battery can no longer supply power to the first relay module 5 and the second relay module 6 through the protection module 3, stopping charging of the load capacitor 7.

[0025] After the load capacitor 7 completes its pre-charge, the battery powers the load motor. The host computer sends high-level signals to the first relay module 5 and the second relay module 6, causing them to close. After the first relay module 5 closes, the electrical signal output from the battery powers the load motor through the first relay module 5 and the second relay module 6.

[0026] When the load motor stops working, the host computer sends a low-level signal to the first relay module 5, causing the first relay module 5 to be turned off. The battery cannot supply power to the load motor through the first relay module 5, and the battery system is in standby mode at this time.

[0027] After the battery system shuts down, high-voltage energy may still remain in the load capacitor 7. Without proper safety release, this could pose a risk of electric shock to maintenance personnel or equipment. After shutdown, the host computer sends a pre-discharge signal to the system. At this time, the host computer sends a high-level signal to the input of the pre-discharge control module 2, a low-level signal to the first relay module 5, and a high-level signal to the second relay module 6. Upon receiving the high-level signal, the pre-discharge control module 2 turns on and simultaneously sends a low-level signal to the pre-charge control module 1, causing it to turn off. The first relay module 5 turns off upon receiving the low-level signal, and the second relay module 6 turns on upon receiving the high-level signal. Once the second relay module 6 turns on, the load capacitor 7 discharges. The discharge signal from the load capacitor 7 passes through the second relay module 6, then through the resistor module 4, and finally through the pre-discharge control module 2 to ground, thus discharging the load capacitor 7. When the host computer detects that the load capacitor 7 has finished discharging, it sends a low-level signal to the pre-amplification control module 2, causing the pre-amplification control module 2 to shut down. This disconnects the discharge path of the load capacitor 7, stopping its discharge. In this example, when the voltage of the load capacitor 7 is detected to be less than 1V, it is determined that the load capacitor 7 has finished discharging.

[0028] Furthermore, by connecting the first relay module 5 and the second relay module 6 in series, when the host computer controls the first relay module 5 to disconnect, the host computer detects whether the first relay module 5 is completely disconnected by checking for voltage. If voltage remains after disconnection, it is determined that the first relay module 5 is stuck and not completely disconnected. At this time, the host computer sends a low-level signal to the second relay module 6, causing the second relay module 6 to disconnect. After the second relay module 6 disconnects, the pre-charge and pre-discharge control circuit of the battery system is completely disconnected from the load capacitor 7 and the load motor. This effectively prevents the first relay module 5 from sticking and failing to disconnect, which could lead to the battery system being unable to cut off the output and causing over-discharge of the battery.

[0029] Furthermore, the precharge control module 1 includes a control chip U1, a MOSFET Q24, and a MOSFET Q15; the control chip U1 has an input terminal and an output terminal. The gate of the MOSFET Q24 is connected to the input terminal of the control chip U1, the source of the MOSFET Q24 shares a common ground terminal with the input terminal of the control chip U1, and the drain of the MOSFET Q24 is connected to the pre-amplification control module 2. The output terminal of the control chip U1 is connected to the pre-amplification control module 2 and the gate of the MOSFET Q15, respectively. The source of the MOSFET Q15 is grounded, and the drain of the MOSFET Q15 is connected to the protection module 3.

[0030] In this example, the control chip U1 is a gate driver chip. Control chip U1 has an IN terminal, a VCC terminal, a COM terminal, an OUT1 terminal, and an OUT2 terminal. The IN terminal is the input terminal of control chip U1, and the OUT1 and OUT2 terminals are the output terminals of control chip U1. The VCC terminal of control chip U1 is connected to a 12V power supply. The pre-charge control module 1 also includes a capacitor C203. One end of capacitor C203 is connected to both the 12V power supply and the VCC terminal, and the other end is connected to both the COM terminal and ground. Capacitor C203 is used for filtering.

[0031] The precharge control module 1 also includes resistors R183, R186, R188, R182, and R193. Resistor R183 is connected to the IN terminal of control chip U1 and is used for current limiting. One end of resistor R188 is connected to resistor R186 and the IN terminal of control chip U1, and the other end is connected to the source and ground of MOSFET Q24. One end of resistor R186 is connected to resistor R188 and the IN terminal of control chip U1, and the other end is connected to the gate of MOSFET Q24. Resistor R186 is a current-limiting resistor for the gate of MOSFET Q24 to prevent excessive input current from damaging MOSFET Q24. At the same time, resistors R186 and R188 form a voltage divider network for MOSFET Q24, providing bias voltage for MOSFET Q24. One end of resistor R182 is connected to the OUT1 and OUT2 terminals of control chip U1, and the other end is connected to the gate of MOSFET Q15. One end of resistor R193 is connected to resistor R182 and the gate of MOSFET Q15, while the other end is grounded with the source of MOSFET Q15. Resistor R182 is the current-limiting resistor for the gate of MOSFET Q15, and resistor R193 is used to provide bias voltage for MOSFET Q15.

[0032] The preamplifier control module 2 includes a control chip U2, a MOSFET Q22, and a MOSFET Q12. The control chip U2 has an input terminal and an output terminal. The input terminal is connected to the gate of MOSFET Q22, and the output terminal is connected to the gate of MOSFET Q12 and the drain of MOSFET Q24. The drain of MOSFET Q22 is connected to the output terminal of control chip U1 and the gate of MOSFET Q15, and the source of MOSFET Q22 is grounded. The drain of MOSFET Q12 is connected to the protection module 3 and the resistor module 4, and the source of MOSFET Q12 is grounded.

[0033] In this example, the control chip U2 is a gate driver chip. Control chip U2 has IN, VCC, COM, OUT1, and OUT2 terminals. The IN terminal is the input terminal of control chip U2, and OUT1 and OUT2 are the output terminals of control chip U2. The preamplifier control module 2 also includes a capacitor C295. One end of capacitor C295 is connected to the 12V power supply and the VCC terminal, and the other end is connected to the COM terminal and ground.

[0034] The preamplifier control module 2 also includes resistors R304, R187, R189, R161, and R309. Resistor R304 is connected to the IN terminal of control chip U2 and is used for current limiting. One end of resistor R187 is connected to both the input terminal of preamplifier control module 2 and the IN terminal of control chip U2, and the other end is connected to the gate of MOSFET Q22; resistor R187 is used for current limiting. One end of resistor R189 is connected to R187, the input terminal of preamplifier control module 2, and the IN terminal of control chip U2, and the other end is grounded. Resistors R189 and R187 together form a voltage divider network for MOSFET Q22, dividing the voltage of the input signal to MOSFET Q22. One end of resistor R161 is connected to both the OUT1 and OUT2 terminals of control chip U2, and the other end is connected to the gate of MOSFET Q12; resistor R161 is used to limit the current of the input signal to the gate of MOSFET Q12. One end of resistor R309 is connected to resistor R161 and the gate of MOSFET Q12, and the other end is grounded together with the source of MOSFET Q12. Resistor R309 is used to provide bias voltage for MOSFET Q12.

[0035] When the host computer sends a precharge signal, the precharge control module 1 inputs a high-level signal, and the pre-amplification control module 2 inputs a low-level signal. Simultaneously, the host computer sends a low-level signal to the first relay module 5 and a high-level signal to the second relay module 6. The IN terminal of control chip U1 and the gate of MOSFET Q24 receive the high-level signal. After the IN terminal of control chip U1 receives the high-level signal, the OUT1 and OUT2 terminals of control chip U1 output high-level signals to the gate of MOSFET Q15, causing MOSFET Q15 to conduct. After MOSFET Q15 conducts, it sends a low-level signal to protection module 3, causing protection module 3 to conduct. After the gate of MOSFET Q24 receives the high-level signal, MOSFET Q24 conducts. At this time, the drain of MOSFET Q24 outputs a low-level signal to the gate of MOSFET Q12, causing the gate of MOSFET Q12 to cut off, thus preventing the pre-amplification control module 2 from conducting. When the protection module 3 is turned on, the electrical signal output by the battery passes sequentially through the protection module 3 and the resistor module 4 before being input to the first relay module 5 and the second relay module 6, energizing them. Simultaneously, the first relay module 5 is turned off upon receiving a low-level signal, while the second relay module 6 is turned on upon receiving a high-level signal. The electrical signal output by the battery is then output to the load capacitor 7 via the second relay module 6, charging the load capacitor 7.

[0036] When the host computer sends a preamplification signal, the input terminal of preamplification control module 2 receives a high-level signal, and the input terminal of precharge control module 1 receives a low-level signal. At this time, the IN terminal of control chip U2 and the gate of MOSFET Q22 receive high-level signals. After receiving the high-level signal, control chip U2 outputs high-level signals at its OUT1 and OUT terminals, and then the gate of MOSFET Q12 receives a high-level signal, causing MOSFET Q12 to conduct. When the gate of MOSFET Q22 receives a high-level signal, MOSFET Q22 conducts. At this time, the drain of MOSFET Q22 is at a low level, thus the gate of MOSFET Q15 is at a low level, preventing MOSFET Q15 from conducting. Thus, when precharge control module 1 is on, preamplification control module 2 is off; when preamplification control module 2 is on, precharge control module 1 is off, interlocking precharge control module 1 and preamplification control module 2 to prevent circuit malfunctions caused by simultaneous operation of precharge control module 1 and preamplification control module 2. After the pre-amplification control module 2 is turned on, the electrical signal released by the load capacitor 7 is output through the second relay module 6, and then discharged to the ground through the resistor module 4 and the MOSFET Q12.

[0037] Furthermore, the protection module 3 includes a MOSFET Q16, a Zener diode Z20, a MOSFET Q17, and a fuse assembly 31. The gate of MOSFET Q16 is connected to the precharge control module 1, the drain of MOSFET Q16 is connected to the positive terminal of the battery, the source of MOSFET Q16 is connected to the negative terminal of Zener diode Z20 and the source of MOSFET Q7, the positive terminal of Zener diode Z20 is connected to the precharge control module 1, the gate of MOSFET Q16, and the gate of MOSFET Q17, the drain of MOSFET Q17 is connected to one end of the fuse assembly 31, and the other end of the fuse assembly 31 is connected to the pre-discharge control module 2 and the resistor module 4.

[0038] When the host computer sends a precharge signal, the precharge control module 1 is turned on. After the precharge control module 1 is turned on, the drain of MOSFET Q15 sends a low-level signal to the gates of MOSFET Q16 and Q17. After the gate of MOSFET Q16 receives the low-level signal, MOSFET Q16 turns on. After MOSFET Q16 turns on, MOSFET Q17 turns on. The electrical signal output from the battery passes through MOSFET Q16, MOSFET Q17 and fuse assembly 31 in sequence before being input to resistor module 4. Then, after passing through resistor module 4, it supplies power to the first relay module 5 and the second relay module 6.

[0039] Fuse assembly 31 is used to melt itself and cut off the circuit in the event of current overload or short circuit, thereby protecting the components in the circuit. In this example, fuse assembly 31 includes fuse F7 and fuse F8, which are connected in parallel.

[0040] In this example, the protection module 3 also includes resistors R273 and R184, and diode D31. One end of resistor R273 is connected to the output terminal of the precharge control module 1, and the other end is connected to the gate of MOSFET Q16, the anode of Zener diode Z20, and the gate of MOSFET Q17, respectively. Resistor R273 is used for current limiting. One end of resistor R184 is connected to resistor R273, the gate of MOSFET Q16, the anode of Zener diode Z20, and the gate of MOSFET Q17, respectively. The other end is connected to the source of MOSFET Q16, the cathode of Zener diode Z20, and the drain of MOSFET Q17, respectively. Resistor R184 is used to provide bias voltage for MOSFET Q16. The anode of diode D31 is connected to the source of MOSFET Q17, and the other end is connected to fuse assembly 31. Diode D31 is used to prevent reverse current flow.

[0041] Furthermore, the protection module 3 also includes a Zener diode Z19. The negative terminal of the Zener diode Z19 is connected to the first relay module 5 and the power supply voltage, respectively, and its positive terminal is connected to the drain of MOSFET Q13 and the drain of MOSFET Q14.

[0042] Zener diode Z19 is used to prevent the battery from being connected in reverse. When the battery is connected in reverse, Zener diode Z19 will burn out, thus alerting the operator that the battery is connected in reverse.

[0043] The first relay module 5 includes a first relay 51, a first RC unit 52, and a first control unit 53. The first relay 51 has a first switch terminal, a second switch terminal, a first coil terminal, and a second coil terminal. The first switch terminal of the first relay 51 is connected to the positive terminal of the battery, the second switch terminal is connected to the first RC unit 52 and the resistor module 4, the first coil terminal of the first relay 51 is connected to the power supply voltage, and its second coil terminal is connected to the first control unit 53.

[0044] Furthermore, the first control unit 53 includes a MOSFET Q13, a resistor R128 and a resistor R267. The gate of the MOSFET Q13 is connected to the resistors R128 and R267 respectively. The other end of the resistor R267 is grounded together with the source of the MOSFET Q13. The drain of the MOSFET Q13 is connected to the power supply voltage and the first coil terminal.

[0045] When the host computer sends a high-level signal to the first relay module 5, the gate of MOSFET Q13 receives the high-level signal, and then MOSFET Q13 turns on. After MOSFET Q13 turns on, the first coil terminal and the second coil terminal of the first relay 51 are energized, which then causes the first relay 51 to close and conduct. When the host computer controls the first relay module 5 to close, the host computer sends a low-level signal to the first relay module 5. The low-level signal is input to the gate of MOSFET Q13, causing MOSFET Q13 to turn off, thus preventing the first relay 51 from being energized and conducting, and the first relay module 5 is disconnected.

[0046] After the first relay 51 is closed, the electrical signal output by the battery passes through the first relay 51 and is input into the first RC unit 52, and then output after passing through the first RC unit 52.

[0047] Furthermore, the first RC unit 52 includes resistors R265, R266, and R174, and capacitor C262. One end of resistor R265 is connected to resistor module 4 and the second switch terminal, and its other end is connected to resistors R174 and R266. One end of resistor R266 is connected to capacitor C262, and the other end of capacitor C262 is grounded together with resistor R174. Resistors R265, R266, and R174 form a voltage divider network, and capacitor C262 is used for filtering. In practical applications, the host computer detects the voltage of the first relay 51 by connecting the common contact of resistor R266 and capacitor C262.

[0048] The second relay module 6 includes a second relay 61, a second RC unit 62, and a second control unit 63. The second relay 61 has a third switch terminal, a fourth switch terminal, a third coil terminal, and a fourth coil terminal. The third switch terminal is connected to the resistor module 4 and the second switch terminal, respectively. The fourth switch terminal is connected to the second RC unit 62. The third coil terminal is connected to the power supply voltage. The fourth coil terminal is connected to the second control unit 63.

[0049] The second control unit 63 includes a MOSFET Q14, a resistor R277, and a resistor R155. The gate of the MOSFET Q14 is connected to one end of both resistors R277 and R155, and the source of the MOSFET Q14 is grounded to the other end of resistor R277. The drain of the MOSFET Q14 is connected to the fourth coil terminal and the power supply voltage.

[0050] When the host computer controls the second relay module 6 to close, the host computer sends a high-level signal to the second control unit 63. This high-level signal, after being current-limited by resistor R155, is input to the gate of MOSFET Q14, causing MOSFET Q14 to conduct. With MOSFET Q14 conducting, the fourth coil terminal of the second relay 61 is energized, and then the second relay 61 closes, causing the second relay module 6 to close and conduct. When the host computer controls the second relay module 6 to open, the host computer sends a low-level signal to the second control unit 63. This low-level signal is input to the gate of MOSFET Q14, causing MOSFET Q14 to turn off. At this time, the fourth terminal of the second relay 61 cannot be energized, and the second relay 61 remains open, thus the second relay module 6 is in the open state.

[0051] The battery system precharge and pre-discharge control circuit in this example also includes a diode D9. The negative terminal of the diode D9 is connected to the first coil terminal of the first relay 51 and the power supply voltage, respectively, and its positive terminal is connected to the first control unit 53 and the second control unit 63.

[0052] In this example, the cathode of diode D9 is connected to the first coil terminal of the first relay 51 and the power supply voltage, while its anode is connected to the drain of MOSFET Q13 and the drain of MOSFET Q14. Diode D9 is used to freewheel current for MOSFETs Q13 and Q14 to reduce the peak voltages of MOSFETs Q13 and Q14.

[0053] The second RC unit 62 includes resistors R163, R165, and R164, and capacitor C294. One end of resistor R163 is connected to the load capacitor 7, and its other end is connected to one end of resistor R165 and one end of resistor R164. The other end of resistor R164 is grounded. The other end of resistor R165 is connected to capacitor C294, and the other end of capacitor C294 and resistor R164 are grounded together.

[0054] Resistor module 4 includes multiple resistors connected in parallel. In this example, resistor module 4 includes twenty 100R / 2W resistors connected in parallel. It should be noted that resistors in resistor module 4 can be replaced with different resistors to meet different discharge voltage requirements, thus adapting the power of resistor module 4 to the application scenario.

[0055] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. A precharge and pre-discharge control circuit for a battery system, comprising a positive battery connection terminal and a negative battery connection terminal, characterized in that, include: The precharge control module (1), pre-discharge control module (2), protection module (3), resistor module (4), first relay module (5), second relay module (6), and load capacitor (7) are configured. The output terminal of the precharge control module (1) is connected to the protection module (3). The precharge control module (1) is also connected to the pre-discharge control module (2), and the precharge control module (1) and the pre-discharge control module (2) are interlocked. The protection module (3) is connected to the positive terminal of the battery, the pre-discharge control module (2), and the resistor module (4). The negative terminal of the battery is grounded. The first relay module (5) and the second relay module (6) are connected to the resistor module (4), and the first relay module (5) and the second relay module (6) are connected in series. The load capacitor (7) is connected to the second relay module (6).

2. The pre-charge and pre-discharge control circuit of the battery system according to claim 1, characterized in that, The precharge control module (1) includes a control chip U1, a MOS transistor Q24, and a MOS transistor Q15. The control chip U1 has an input terminal and an output terminal. The gate of the MOS transistor Q24 is connected to the input terminal of the control chip U1, and its source is grounded together with the input terminal of the control chip U1. The drain of the MOS transistor Q24 is connected to the pre-amplification control module (2). The output terminal of the control chip U1 is connected to the pre-amplification control module (2) and the gate of the MOS transistor Q15. The source of the MOS transistor Q15 is grounded, and the drain of the MOS transistor Q15 is connected to the protection module (3).

3. The pre-charge and pre-discharge control circuit of the battery system according to claim 1, characterized in that, The protection module (3) includes a MOSFET Q16, a Zener diode Z20, a MOSFET Q17, and a fuse assembly (31). The gate of the MOSFET Q16 is connected to the precharge control module (1), and the drain of the MOSFET Q16 is connected to the positive terminal of the battery. The source of the MOSFET Q16 is connected to the negative terminal of the Zener diode Z20 and the source of the MOSFET Q7. The positive terminal of the Zener diode Z20 is connected to the precharge control module (1), the gate of the MOSFET Q16, and the gate of the MOSFET Q17. The drain of the MOSFET Q17 is connected to one end of the fuse assembly (31), and the other end of the fuse assembly (31) is connected to the pre-discharge control module (2) and the resistor module (4).

4. The pre-charge and pre-discharge control circuit of the battery system according to claim 2, characterized in that, The pre-amplification control module (2) includes a control chip U2, a MOS transistor Q22 and a MOS transistor Q12. The control chip U2 has an input terminal and an output terminal. The input terminal is connected to the gate of the MOS transistor Q22. The output terminal of the control chip U2 is connected to the gate of the MOS transistor Q12 and the drain of the MOS transistor Q24. The drain of the MOS transistor Q22 is connected to the output terminal of the control chip U1 and the gate of the MOS transistor Q15. The source of the MOS transistor Q22 is grounded. The drain of the MOS transistor Q12 is connected to the protection module (3) and the resistor module (4). The source of the MOS transistor Q12 is grounded.

5. The pre-charge and pre-discharge control circuit of the battery system according to claim 1, characterized in that, The first relay module (5) includes a first relay (51), a first RC unit (52) and a first control unit (53); the first relay (51) has a first switch terminal, a second switch terminal, a first coil terminal and a second coil terminal; the first switch terminal of the first relay (51) is connected to the positive connection terminal of the battery, the second switch terminal is connected to the first RC unit (52) and the resistor module (4) respectively, the first coil terminal of the first relay (51) is connected to the power supply voltage, and its second coil terminal is connected to the first control unit (53).

6. The pre-charge and pre-discharge control circuit of the battery system according to claim 5, characterized in that, The second relay module (6) includes a second relay (61), a second RC unit (62), and a second control unit (63); the second relay (61) has a third switch terminal, a fourth switch terminal, a third coil terminal, and a fourth coil terminal. The third switch terminal is connected to the resistor module (4) and the second switch terminal respectively. The fourth switch terminal is connected to the second RC unit (62) and the load capacitor (7). The third coil terminal is connected to the power supply voltage. The fourth coil terminal is connected to the second control unit (63).

7. The pre-charge and pre-discharge control circuit of the battery system according to claim 5, characterized in that, The first RC unit (52) includes resistors R265, R266, R174 and capacitor C262. One end of resistor R265 is connected to the resistor module (4) and the second switch terminal, and the other end is connected to resistors R174 and R266 respectively. One end of resistor R266 is connected to capacitor C262, and the other end of capacitor C262 is grounded together with resistor R174.

8. The pre-charge and pre-discharge control circuit of the battery system according to claim 5, characterized in that, The first control unit (53) includes a MOS transistor Q13, a resistor R128 and a resistor R267. The gate of the MOS transistor Q13 is connected to the resistor R128 and the resistor R267 respectively. The other end of the resistor R267 is grounded together with the source of the MOS transistor Q13. The drain of the MOS transistor Q13 is connected to the power supply voltage and the first coil terminal.

9. The pre-charge and pre-discharge control circuit of the battery system according to claim 3, characterized in that, The protection module (3) also includes a Zener diode Z19, the negative terminal of which is connected to the drain positive terminal of the MOS transistor Q16, and the negative terminal is connected to the negative terminal of the battery and the ground terminal.

10. The pre-charge and pre-discharge control circuit of the battery system according to claim 6, characterized in that, It also includes a diode D9, the negative terminal of which is connected to the first coil terminal and the power supply voltage, and its positive terminal is connected to the first control unit (53) and the second control unit (63).

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