Pre-charging and pre-discharging control circuit, pre-charging control method and pre-discharging control method

Abstract

The invention provides a pre-charging and pre-discharging control circuit, a pre-charging control method and a pre-discharging control method. The pre-charging and pre-discharging control circuit comprises a pre-charging control module, a pre-discharging control module, a temperature protection switch module, a current limiting module and a host awakening module. After the pre-charging control module, the pre-discharging control module, the temperature protection switch module and the current limiting module are connected in series, one end is connected with a positive electrode of a battery pack, and the other end is connected with a load positive electrode port; the host awakening module is connected in parallel with the current limiting module; and the pre-charging and discharging control circuit is also in communication connection with a processor MCU in the battery pack system. Through the design of the pre-charging and discharging control circuit, the pre-charging and discharging control of the battery pack system can be effectively and efficiently realized, the rapid pre-charging and discharging function with multiple safety protections can be realized with lower material cost and production cost, and the cost performance incomparable to other schemes is achieved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a pre-charge and discharge control circuit, a pre-charge control method and a pre-discharge control method. Background Art

[0002] With the development of battery-powered systems, more and more large-capacity battery projects are being developed and put into the terminal market. Large-capacity battery cells are of high value and require a long total usage time. However, if the battery pack is not recharged after a long period of power loss, it is easy to cause the battery cell voltage to be too low. For safety reasons, it must be charged with a small current until the battery reaches the over-discharge voltage, and then it can be charged with a standard charging current. As a result, various pre-charging strategies and circuits have been generated.

[0003] There are several general pre-charging circuits: 1. Use large-value resistors to limit current. In this type of circuit, the pre-charging current is small and the pre-charging time is the longest. 2. Use medium-value resistors to limit current and significantly reduce the output power of the charger to avoid resistor over-power. The pre-charging current of this type of circuit is larger than the first one. Although the pre-charging time is shortened, the battery pack MCU must communicate with the charger, and the system becomes complicated. There are also high requirements for the charger, which must be able to work stably after reducing the power.

[0004] In most cases, the load of the battery resistor contains large capacitance, and the instantaneous large current output by the battery pack may cause a short circuit problem. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a pre-charge and discharge control circuit, a pre-charge control method and a pre-discharge control method.

[0006] In a first aspect, the present application provides a pre-charge control circuit, comprising: Pre-charge control module, pre-discharge control module, temperature protection switch module, current limiting module and host wake-up module.

[0007] in, The pre-charge control module, the pre-discharge control module, the temperature protection switch module and the current limiting module are connected in series with one end connected to the positive electrode of the battery pack and the other end connected to the positive electrode port of the load.

[0008] The host wake-up module is connected in parallel with the current limiting module.

[0009] in, The pre-charge and discharge control circuit is also connected to the processor MCU in the battery pack system for communication.

[0010] The pre-charge control module is used to control the opening or closing of the pre-charge circuit, the pre-discharge control module is used to control the opening or closing of the pre-discharge circuit, the temperature protection switch module and the current limiting module are used to control the current size of the pre-charge circuit and the pre-discharge circuit, and the host wake-up module is used to activate the main discharge circuit.

[0011] Since there is a communication connection between the modules in the pre-charge and discharge control circuit and the processor MCU in the battery pack system, the processor MCU can timely obtain parameter information in the pre-charge and discharge control circuit, such as voltage, current or temperature, and perform corresponding operations based on the obtained parameter information.

[0012] Furthermore, the pre-filling control module includes: Pre-charged MOS tube, pre-charged switch unit and pre-charged protection unit.

[0013] in, The drain of the pre-charge MOS tube is connected to the positive electrode of the battery pack, and the source of the pre-charge MOS tube is connected to the pre-discharge control module.

[0014] The input end of the pre-charge switch unit is connected to the first signal generator, and the output end of the pre-charge switch unit is connected to the gate of the pre-charge MOS tube.

[0015] The pre-charge protection unit is connected in parallel between the gate and source of the pre-charge MOS tube.

[0016] in, The pre-charging switch unit at least includes a pre-charging switch MOS tube.

[0017] The pre-charge protection unit at least includes a pre-charge voltage regulator diode.

[0018] The pre-charge switch unit receives the signal sent by the first signal generator and is turned on when a high level is received. The output end of the pre-charge switch unit is connected to the gate of the pre-charge MOS tube. When the pre-charge switch unit is turned on, the gate of the pre-charge MOS tube receives a high level, and then the pre-charge MOS tube is turned on, and the pre-charge circuit is turned on. Through this inventive design, double protection can be set for the pre-charge circuit.

[0019] The pre-charge protection unit is connected in parallel between the gate and source of the pre-charge MOS tube to prevent the VGS of the pre-charge MOS tube from exceeding the safety voltage.

[0020] Furthermore, the pre-release control module includes: Pre-amplifier MOS tube, pre-amplifier switch unit and pre-amplifier protection unit.

[0021] in, The source of the pre-discharge MOS tube is connected to the pre-charge control module, and the drain of the pre-discharge MOS tube is connected to the temperature protection switch module.

[0022] The input end of the pre-amplifier switch unit is connected to the second signal generator, and the output end of the pre-amplifier switch unit is connected to the gate of the pre-amplifier MOS tube.

[0023] The pre-discharge protection unit is connected in parallel between the gate and source of the pre-discharge MOS tube.

[0024] in, The pre-amplifier switch unit at least includes a pre-amplifier switch MOS tube.

[0025] The pre-discharge protection unit at least includes a pre-discharge voltage-stabilizing diode.

[0026] The pre-amplifier switch unit receives the signal sent by the second signal generator, and is turned on when a high level is received. The output end of the pre-amplifier switch unit is connected to the gate of the pre-amplifier MOS tube. When the pre-amplifier switch unit is turned on, the gate of the pre-amplifier MOS tube receives a high level, and then the pre-amplifier MOS tube is turned on, and the pre-amplifier loop is turned on. Through this inventive design, double protection can be set for the pre-amplifier loop.

[0027] The pre-discharge protection unit is connected in parallel between the gate and source of the pre-discharge MOS tube to prevent the VGS of the pre-discharge MOS tube from exceeding the safety voltage.

[0028] Furthermore, the first signal generator is located in the processor MCU.

[0029] Furthermore, the second signal generator is located in the processor MCU.

[0030] Furthermore, one end of the temperature protection switch module is connected to the pre-release control module, and the other end is connected to the current limiting module.

[0031] The temperature protection switch module is used to limit the temperature of the pre-charge and discharge control circuit. If the pre-charge MOS is out of control, the temperature of the pre-charge and discharge control circuit will continue to rise, and the temperature switch will shut down the pre-charge circuit in time to achieve the protection purpose.

[0032] Furthermore, one end of the current limiting module is connected to the temperature protection switch module, and the other end is connected to the load positive electrode port.

[0033] in, The current limiting module includes two current limiting resistors connected in parallel and having NTCs placed thereon.

[0034] The current limiting module is used to assist the processor MCU in controlling the current of the pre-charge and discharge circuit. The current limiting module includes two current limiting resistors placed in parallel with NTCs. The NTC can collect the temperature of the current limiting resistors and send it to the processor MCU. The processor MCU controls the signal frequency of the first signal generator or the second signal generator based on the temperature.

[0035] Furthermore, the host wake-up module includes: A first switch transistor, a first switch MOS tube, a first voltage-dividing resistor, a second voltage-dividing resistor, a third voltage-dividing resistor, a fourth voltage-dividing resistor, and a first diode.

[0036] The emitter of the first transistor is connected to the temperature protection switch module, the collector of the first transistor is connected to the input end of the third voltage-dividing resistor, and the base of the first transistor is connected to the input end of the second voltage-dividing resistor.

[0037] The source of the first switch MOS tube is connected to the processor MCU, the drain of the first switch MOS tube is grounded, and the gate of the first switch MOS tube is connected to the output end of the third voltage-dividing resistor.

[0038] The cathode of the first diode is connected to the output end of the second voltage-dividing resistor, and the anode of the first diode is connected to the positive electrode interface of the load.

[0039] The input end of the first voltage-dividing resistor is connected to the emitter of the first switching transistor, and the output end of the first voltage-dividing resistor is connected to the base of the first switching transistor.

[0040] The input end of the fourth voltage-dividing resistor is connected to the gate of the first switch MOS tube, and the output end of the fourth voltage-dividing resistor is grounded.

[0041] The host wake-up module can collect the voltage of the current limiting resistor in the current limiting module, and generate a corresponding high / low level signal to the processor MCU based on the voltage. The processor MCU starts / does not start the main release circuit based on the high / low level signal. Through the design of the present invention, the entire battery pack system can be started smoothly with load and effectively reduce the power consumption of the battery pack itself.

[0042] In a second aspect, the present application proposes a pre-filling control method, the pre-filling control method comprising: The processor MCU controls the first signal generator to generate a PWM signal with an adjustable duty cycle. When the PWM signal is at a high level, the pre-charge control module starts the pre-charge circuit until the battery pack reaches the over-discharge voltage, and the processor MCU controls the main charging circuit to be turned on.

[0043] The current limiting module collects the module temperature and sends it to the processor MCU. The processor MCU adjusts the duty cycle of the PWM signal according to the module temperature.

[0044] The temperature protection switch module limits the temperature of the pre-charge and discharge control circuit and cuts off the circuit when the temperature reaches a threshold temperature.

[0045] In a third aspect, the present application proposes a pre-release control method, the pre-release control method comprising: The processor MCU controls the second signal generator to generate a PWM signal with an adjustable duty cycle. When the PWM signal is at a high level, the pre-amplifier control module turns on the pre-amplifier loop. When the voltage of the current limiting module reaches the second threshold voltage, the host wake-up module is turned on, and a signal is sent to the processor MCU, and the processor MCU starts the main release circuit.

[0046] The current limiting module collects the module temperature and sends it to the processor MCU. The processor MCU adjusts the duty cycle of the PWM signal according to the module temperature.

[0047] The temperature protection switch module limits the temperature of the pre-charge and discharge control circuit and cuts off the circuit when the temperature reaches a threshold temperature.

[0048] In summary, the present application proposes a pre-charge and discharge control circuit, a pre-charge control method and a pre-discharge control method. The pre-charge and discharge control circuit includes a pre-charge control module, a pre-discharge control module, a temperature protection switch module, a current limiting module and a host wake-up module; the pre-charge control module, the pre-discharge control module, the temperature protection switch module and the current limiting module are connected in series, one end of which is connected to the positive electrode of the battery pack, and the other end is connected to the positive electrode port of the load; the host wake-up module is connected in parallel with the current limiting module; the pre-charge and discharge control circuit is also communicatively connected to the processor MCU in the battery pack system.

[0049] Compared with the prior art, this application has at least the following beneficial effects: This solution can effectively and efficiently realize the pre-charge and discharge control of the battery pack system, and can realize the fast pre-charge and discharge functions with multiple safety protections at a lower material cost and production cost, and has a cost-effectiveness that other solutions cannot match.

[0050] This solution uses a small-value resistor to limit the current and uses PWM to control the pre-charge MOS tube. There is no need to adjust the output power of the charger, and a pre-discharge control module is added to avoid short-circuit problems caused by the battery pack releasing large current instantly. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a structural diagram of the pre-charge and discharge control circuit shown in an embodiment of the present application.

[0052] Figure 2 It is a schematic diagram of the pre-charging control module shown in an embodiment of the present application.

[0053] Figure 3 It is a schematic diagram of a pre-release control module shown in an embodiment of the present application.

[0054] Figure 4 It is a schematic diagram of a temperature protection switch module and a current limiting module shown in an embodiment of the present application.

[0055] Figure 5 It is a schematic diagram of a host wake-up module shown in an embodiment of the present application. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] Embodiment 1: The present application provides a pre-charge control circuit, comprising: Pre-charge control module, pre-discharge control module, temperature protection switch module, current limiting module and host wake-up module.

[0058] in, The pre-charge control module, the pre-discharge control module, the temperature protection switch module and the current limiting module are connected in series with one end connected to the positive electrode of the battery pack and the other end connected to the positive electrode port of the load.

[0059] The host wake-up module is connected in parallel with the current limiting module.

[0060] in, The pre-charge and discharge control circuit is also connected to the processor MCU in the battery pack system for communication.

[0061] In the embodiment of the present invention, optionally, as shown in the attached Figure 1 As shown, the circuit structure of each module can be clearly seen; the main components of the pre-charge control module and the pre-discharge control module are two PMOS tubes and a diode; the temperature protection switch module is composed of a fuse; the current limiting module is composed of two current limiting resistors with NTC placed in parallel; the host wake-up module is composed of a transistor, a PMOS tube, four voltage-dividing resistors and a diode.

[0062] In the embodiment of the present invention, the fuse is optionally a three-terminal fuse, which generally refers to a fuse assembly with three pins, also known as a "three-terminal fuse" or a "three-terminal fuse tube". This type of fuse is generally used in a DC circuit, and its main function is to provide protection against overcurrent or overload conditions in the circuit.

[0063] A three-terminal fuse usually consists of a fuse element, two electrode pins and a ground pin. The fuse element is generally located between the two electrode pins. When the fuse is broken, it will disconnect the circuit between the two electrode pins.

[0064] When the current in the circuit exceeds the rated current (overload current) of the three-terminal fuse, the fuse element heats up and eventually melts. This melting interrupts the circuit between the two electrode pins, preventing the overcurrent from continuing to flow, thereby protecting other components in the circuit from damage.

[0065] In the embodiment of the present invention, NTC (Negative Temperature Coefficient) is a negative temperature coefficient thermistor, which is a resistor device that changes its resistance value according to temperature changes. Specifically: Negative temperature coefficient: As the temperature increases, the resistance of NTC decreases; when the temperature decreases, the resistance increases. This reverse resistance-temperature characteristic makes NTC widely used in temperature measurement and control circuits.

[0066] NTCs are usually made of metal oxide ceramics, whose main components are usually nickel oxide (NiO) or zinc oxide (ZnO), and their resistance-temperature characteristics are adjusted by adding appropriate amounts of other metal oxides.

[0067] In the embodiment of the present invention, optionally, as shown in the attached Figure 2 As shown, the pre-charge control module includes: Pre-charge MOS tube Q1, pre-charge switch unit and pre-charge protection unit.

[0068] The pre-charge switch unit includes a pre-charge switch MOS tube Q4, a resistor R2, a resistor R8, a resistor R11 and a resistor R13.

[0069] The pre-charge protection unit includes a diode Z2.

[0070] The input end of the resistor R11 is connected to the PCH interface of the processor MCU, and the PCH interface periodically sends a PWM signal with an adjustable duty cycle, and the output end is connected to the gate of the pre-charge switch MOS tube Q4.

[0071] The source of the pre-charging switch MOS tube Q4 is connected to the input end of the resistor R8, and the drain of the pre-charging switch MOS tube Q4 is grounded.

[0072] The resistor R13 is connected between the drain and the gate of the pre-charge switch MOS tube Q4.

[0073] The resistor R2 is connected between the source and the gate of the pre-charge MOS tube Q1.

[0074] The diode Z2 is connected between the source and the gate of the pre-charge MOS tube Q1.

[0075] In an embodiment of the present invention, optionally, the processor MCU periodically sends a PWM signal with an adjustable duty cycle to the gate of the pre-charging MOS tube Q4 through the PCH interface, which can control the pre-charging MOS tube Q4 to be turned on or off; the source of the pre-charging MOS tube Q4 is controlled to be connected to the gate of the pre-charging MOS tube Q1 through the resistor Q8, so as to control the pre-charging MOS tube Q1 to be turned on or off, and thus control the opening or closing of the entire pre-charging loop.

[0076] In the embodiment of the present invention, optionally, the diode Z2 is connected between the gate and the source of the pre-charge MOS tube Q1 to prevent the Vgs of the pre-charge MOS tube Q1 from being over-voltage.

[0077] In the embodiment of the present invention, optionally, as shown in the attached Figure 3 As shown, the pre-amplification control module includes: Pre-amplifier MOS tube Q2, pre-amplifier switch unit and pre-amplifier protection unit.

[0078] The pre-amp switch unit includes a pre-amp switch MOS tube Q3, a resistor R3, a resistor R7, a resistor R10 and a resistor R14.

[0079] The pre-discharge protection unit includes a diode Z1.

[0080] The input end of the resistor R10 is connected to the PDH interface of the processor MCU, and the PDH interface periodically sends a PWM signal with an adjustable duty cycle, and the output end is connected to the gate of the pre-amplifier switch MOS tube Q3.

[0081] The source of the pre-amplifier switch MOS tube Q3 is connected to the input end of the resistor R7, and the drain of the pre-amplifier switch MOS tube Q3 is grounded.

[0082] The resistor R14 is connected between the drain and the gate of the pre-amplifier switch MOS tube Q3.

[0083] The resistor R3 is connected between the source and the gate of the pre-amplifier MOS tube Q2.

[0084] The diode Z2 is connected between the source and the gate of the pre-amplifier MOS tube Q2.

[0085] In an embodiment of the present invention, optionally, the processor MCU periodically sends a PWM signal with an adjustable duty cycle to the gate of the pre-amplifier switch MOS tube Q3 through the PDH interface, which can control the pre-amplifier switch MOS tube Q3 to be turned on or off; the source of the pre-amplifier switch MOS tube Q3 is controlled to be connected to the gate of the pre-amplifier MOS tube Q2 through the resistor Q8, so as to control the pre-amplifier MOS tube Q2 to be turned on or off, thereby controlling the opening or closing of the entire pre-amplifier loop.

[0086] In the embodiment of the present invention, optionally, the diode Z2 is connected between the gate and the source of the pre-discharge MOS tube Q2 to prevent the Vgs of the pre-discharge MOS tube Q2 from being over-voltage.

[0087] It should be noted that the above-mentioned pre-charge control module and pre-discharge control module are only one case proposed in this embodiment. In other embodiments, other circuit forms may also exist, such as adding multiple protection resistors to protect the circuit, or adding voltage divider resistors to adjust parameters. For those skilled in the art, circuits with consistent circuit operation logic should be within the protection scope of this application.

[0088] In the embodiment of the present invention, optionally, as shown in the attached Figure 4 As shown, one end of the temperature protection switch module is connected to the pre-release control module, and the other end is connected to the current limiting module.

[0089] In an embodiment of the present invention, optionally, the temperature protection switch module is composed of a fuse F1, which is connected between the pre-release control module and the current limiting module. The model used is AC250V / 2A, the operating temperature is 85±5℃, and the reset temperature is 60±15℃, but it is not limited to this. Other devices with the same functions can be flexibly selected according to usage requirements.

[0090] The fuse F1 is used to limit the temperature of the pre-charge control circuit. If the pre-charge MOS is out of control, the temperature of the pre-charge control circuit continues to rise. When it reaches about 90°C, the fuse F1 blows and the pre-charge circuit is shut down in time to achieve the purpose of protecting the circuit.

[0091] In the embodiment of the present invention, optionally, as shown in the attached Figure 4 As shown, one end of the current limiting module is connected to the temperature protection switch module, and the other end is connected to the load positive terminal.

[0092] in, The current limiting module includes a first current limiting resistor R1 and a second current limiting resistor R4 which are placed in parallel with NTC.

[0093] In the embodiment of the present invention, optionally, NTC is placed inside the first current limiting resistor R1 and the second current limiting resistor R4. The NTC can collect the temperature of the current limiting resistor and send it to the processor MCU. The processor MCU controls the signal frequency of the signal sent by PCH or PDH according to the temperature.

[0094] In the embodiment of the present invention, the resistance and power of the current limiting resistor are optionally calculated as required. Since this case uses PWM drive, the current limiting resistor is only turned on for 0.25mS in a cycle of 0.5mS, and its power can be calculated according to the pulse power on the device parameters to obtain a larger pre-charge current. When using a current limiting resistor designed with pulse power, the temperature rise needs to be tested in actual applications to ensure that it does not exceed the operating temperature of the temperature protection switch (85±5℃) during normal operation. In the embodiment of the present invention, optionally, as shown in the attached Figure 5 As shown, the host wake-up module includes: A first switch transistor Q5, a first switch MOS tube Q6, a first voltage-dividing resistor R6, a second voltage-dividing resistor R9, a third voltage-dividing resistor R12, a fourth voltage-dividing resistor R15, and a first diode Z3.

[0095] The emitter of the first transistor Q5 is connected to the temperature protection switch module, the collector of the first transistor Q5 is connected to the input end of the third voltage-dividing resistor R12, and the base of the first transistor Q5 is connected to the input end of the second voltage-dividing resistor R6.

[0096] The source of the first switch MOS tube Q6 is connected to the processor MCU, the drain of the first switch MOS tube is grounded, and the gate of the first switch MOS tube Q6 is connected to the output end of the third voltage-dividing resistor R12.

[0097] An input end of the second voltage-dividing resistor R9 is connected to the base of the first transistor Q5 , and an output end of the second voltage-dividing resistor R9 is connected to the cathode of the first diode Z3 .

[0098] The cathode of the first diode Z3 is connected to the output end of the second voltage-dividing resistor R9, and the anode of the first diode Z3 is connected to the positive electrode interface of the load.

[0099] An input end of the first voltage-dividing resistor R6 is connected to the emitter of the first switching transistor Q5 , and an output end of the first voltage-dividing resistor R6 is connected to the base of the first switching transistor Q5 .

[0100] An input end of the fourth voltage-dividing resistor R15 is connected to the gate of the first switch MOS tube Q6 , and an output end of the fourth voltage-dividing resistor R15 is grounded.

[0101] The host wake-up module can collect the voltage of the current limiting resistor in the current limiting module, and generate a corresponding high / low level signal to the processor MCU based on the voltage. The processor MCU starts / does not start the main release circuit based on the high / low level signal. Through the design of the present invention, the entire battery pack system can be started smoothly with load and effectively reduce the power consumption of the battery pack itself.

[0102] In a second aspect, the present application proposes a pre-filling control method, the pre-filling control method comprising: The processor MCU controls the first signal generator to generate a PWM signal with an adjustable duty cycle. When the PWM signal is at a high level, the pre-charge control module starts the pre-charge circuit until the battery pack reaches the over-discharge voltage, and the processor MCU controls the main charging circuit to be turned on.

[0103] The current limiting module collects the module temperature and sends it to the processor MCU. The processor MCU adjusts the duty cycle of the PWM signal according to the module temperature.

[0104] The temperature protection switch module limits the temperature of the pre-charge and discharge control circuit and cuts off the circuit when the temperature reaches a threshold temperature.

[0105] In an embodiment of the present invention, optionally, the first signal generator sends a PWM signal with an adjustable duty cycle to the gate of the pre-charge switch MOS tube Q4. When the PWM is at a low level, the pre-charge switch MOS tube Q4 is turned off, and then the entire pre-charge loop is turned off; when the PWM is at a high level, the pre-charge switch MOS tube Q4 is turned on, and a high level is output to the pre-charge MOS tube Q1, and the pre-charge MOS tube Q1 is turned on, and then the entire pre-charge loop is turned on.

[0106] In an embodiment of the present invention, optionally, the current limiting resistor collects its own temperature and feeds it back to the processor MCU. The processor MCU obtains the current in the entire circuit system at this time based on the temperature. When the current is too large, the processor MCU increases the duty cycle of the PWN signal. When the current is too small, the processor MCU decreases the duty cycle of the PWM signal.

[0107] In the embodiment of the present invention, optionally, when the circuit current is out of control, the circuit temperature will continue to rise until it reaches the operating temperature of the fuse F1 (85±5°C), the fuse F1 will melt, and the entire pre-charging circuit will be disconnected.

[0108] In a third aspect, the present application proposes a pre-release control method, the pre-release control method comprising: The processor MCU controls the second signal generator to generate a PWM signal with an adjustable duty cycle. When the PWM signal is at a high level, the pre-amplifier control module turns on the pre-amplifier loop. When the voltage of the current limiting module reaches the second threshold voltage, the host wake-up module is turned on, and a signal is sent to the processor MCU, and the processor MCU starts the main release circuit.

[0109] The current limiting module collects the module temperature and sends it to the processor MCU. The processor MCU adjusts the duty cycle of the PWM signal according to the module temperature.

[0110] The temperature protection switch module limits the temperature of the pre-charge and discharge control circuit and cuts off the circuit when the temperature reaches a threshold temperature.

[0111] In an embodiment of the present invention, optionally, the second signal generator sends a PWM signal with an adjustable duty cycle to the gate of the pre-amplifier switch MOS tube Q3. When the PWM is at a low level, the pre-amplifier switch MOS tube Q3 is turned off, and then the entire pre-amplifier loop is turned off; when the PWM is at a high level, the pre-amplifier switch MOS tube Q3 is turned on, and a high level is output to the pre-amplifier MOS tube Q2, and the pre-amplifier MOS tube Q2 is turned on, and then the entire pre-amplifier loop is turned on.

[0112] In an embodiment of the present invention, optionally, the host wake-up module can collect the voltage of the current limiting module in parallel. When the current on the current limiting resistor increases, the voltage across the current limiting resistor increases. When the voltage breaks through the first diode Z3, a voltage divider is generated on the first voltage divider resistor R6 and the second voltage divider resistor R9. When the voltage on the first voltage divider resistor R6 reaches the turn-on threshold of the first transistor Q5, the Ic of the first transistor Q5 generates a voltage drop on the second voltage divider resistor R12 and the third voltage divider resistor R15, and then turns on the first switch MOS tube Q6. At this time, the signal PDIS_INT is pulled low. The signal PDIS_INT is connected to the internal pull-up interrupt port of the processor MCU. Therefore, when the pre-discharge current increases, the processor MCU interrupt can be triggered, so that the processor MCU can detect the change in peripheral power consumption and open the main discharge loop in time.

[0113] In an embodiment of the present invention, optionally, the current limiting resistor collects its own temperature and feeds it back to the processor MCU. The processor MCU obtains the current in the entire circuit system at this time based on the temperature. When the current is too large, the processor MCU increases the duty cycle of the PWN signal. When the current is too small, the processor MCU decreases the duty cycle of the PWM signal.

[0114] In the embodiment of the present invention, optionally, when the circuit current is out of control, the circuit temperature will continue to rise until it reaches the operating temperature of the fuse F1 (85±5°C), the fuse F1 will melt, and the entire pre-charging circuit will be disconnected.

[0115] In summary, the present application proposes a pre-charge and discharge control circuit, a pre-charge control method and a pre-discharge control method. The pre-charge and discharge control circuit includes a pre-charge control module, a pre-discharge control module, a temperature protection switch module, a current limiting module and a host wake-up module; the pre-charge control module, the pre-discharge control module, the temperature protection switch module and the current limiting module are connected in series, one end of which is connected to the positive electrode of the battery pack, and the other end is connected to the positive electrode port of the load; the host wake-up module is connected in parallel with the current limiting module; the pre-charge and discharge control circuit is also communicatively connected to the processor MCU in the battery pack system.

[0116] This solution can effectively and efficiently realize the pre-charge and discharge control of the battery pack system, and can realize the fast pre-charge and discharge functions with multiple safety protections at a lower material cost and production cost, and has a cost-effectiveness that other solutions cannot match.

[0117] This solution uses a small-value resistor to limit the current and uses PWM to control the pre-charge MOS tube. There is no need to adjust the output power of the charger, and a pre-discharge control module is added to avoid short-circuit problems caused by the battery pack releasing large current instantly.

[0118] In several embodiments provided in the present application, it is understood that each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved.

[0119] If the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can essentially or in other words, the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for an electronic device to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

[0120] The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the scope of protection of the present application. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A pre-charge control circuit, characterized in that: It includes a pre-charge control module, a pre-discharge control module, a temperature protection switch module, a current limiting module and a host wake-up module; The pre-charge control module is used to control the opening or closing of the pre-charge circuit; the pre-discharge control module is used to control the opening or closing of the pre-discharge circuit; the temperature protection switch module is used to limit the current of the pre-charge control circuit; the current limiting module is used to collect the current size of the pre-charge control circuit; the host wake-up module is used to activate the main discharge circuit; in, The pre-charge control module, the pre-discharge control module, the temperature protection switch module and the current limiting module are connected in series with one end connected to the positive electrode of the battery pack and the other end connected to the positive electrode port of the load; The host wake-up module is connected in parallel with the current limiting module; The pre-charge and discharge control circuit is also connected to the processor MCU in the battery pack system for communication.

2. The pre-charge control circuit according to claim 1, characterized in that: The pre-charge control module comprises: Pre-charge MOS tube, pre-charge switch unit and pre-charge protection unit; in, The drain of the pre-charge MOS tube is connected to the positive electrode of the battery pack, and the source of the pre-charge MOS tube is connected to the pre-discharge control module; The input end of the pre-charging switch unit is connected to the first signal generator, and the output end of the pre-charging switch unit is connected to the gate of the pre-charging MOS tube; The pre-charge protection unit is connected in parallel between the gate and source of the pre-charge MOS tube; in, The pre-charge switch unit at least includes a pre-charge switch MOS tube, which is used to control the conduction or cut-off of the pre-charge control module; The pre-charge protection unit at least includes a pre-charge voltage regulator diode, which is used to protect the pre-charge control module.

3. The pre-charge control circuit according to claim 1, characterized in that: The pre-release control module comprises: Pre-amplifier MOS tube, pre-amplifier switch unit and pre-amplifier protection unit; in, The source of the pre-discharge MOS tube is connected to the pre-charge control module, and the drain of the pre-discharge MOS tube is connected to the temperature protection switch module; The input end of the pre-amplifier switch unit is connected to the second signal generator, and the output end of the pre-amplifier switch unit is connected to the gate of the pre-amplifier MOS tube; The pre-discharge protection unit is connected in parallel between the gate and source of the pre-discharge MOS tube; in, The pre-amplifier switch unit at least includes a pre-amplifier switch MOS tube, which is used to control the conduction or cut-off of the pre-amplifier control module; The pre-discharge protection unit at least includes a pre-discharge voltage-stabilizing diode, which is used to protect the pre-charge control module.

4. The pre-charge control circuit according to claim 2, characterized in that: The first signal generator is located in the processor MCU.

5. The pre-charge control circuit according to claim 3, characterized in that: The second signal generator is located in the processor MCU.

6. The pre-charge control circuit according to claim 1, characterized in that: One end of the temperature protection switch module is connected to the pre-discharge control module, and the other end is connected to the current limiting module, which is used to limit the current of the pre-charge control circuit.

7. The pre-charge control circuit according to claim 1, characterized in that One end of the current limiting module is connected to the temperature protection switch module, and the other end is connected to the load positive electrode port; in, The current limiting module includes two current limiting resistors with NTC placed in parallel, which are used to collect the current size of the pre-charge and discharge control circuit and feed it back to the processor MCU.

8. The pre-charge control circuit according to claim 1, characterized in that: The host wake-up module comprises: A first switch transistor, a first switch MOS tube, a first voltage-dividing resistor, a second voltage-dividing resistor, a third voltage-dividing resistor, a fourth voltage-dividing resistor, and a first diode; The emitter of the first transistor is connected to the temperature protection switch module, the collector of the first transistor is connected to the input end of the third voltage-dividing resistor, and the base of the first transistor is connected to the input end of the second voltage-dividing resistor; The source of the first switch MOS tube is connected to the processor MCU, the drain of the first switch MOS tube is grounded, and the gate of the first switch MOS tube is connected to the output end of the third voltage-dividing resistor; The cathode of the first diode is connected to the output end of the second voltage-dividing resistor, and the anode of the first diode is connected to the positive electrode interface of the load; The first voltage-dividing resistor input end is connected to the emitter of the first switching transistor, and the first voltage-dividing resistor output end is connected to the base of the first switching transistor; The input end of the fourth voltage-dividing resistor is connected to the gate of the first switch MOS tube, and the output end of the fourth voltage-dividing resistor is grounded; The host wake-up module is used to control the opening or closing of the main amplifier circuit.

9. A pre-charge control method based on the pre-charge control circuit according to any one of claims 1 to 8, characterized in that: The pre-filling control method comprises: The processor MCU controls the first signal generator to generate a PWM signal with an adjustable duty cycle. When the PWM signal is at a high level, the pre-charge control module turns on the pre-charge circuit until the battery pack reaches the over-discharge voltage, and the processor MCU controls the main charge circuit to be turned on. The current limiting module collects the module temperature and sends it to the processor MCU, and the processor MCU adjusts the duty cycle of the PWM signal according to the module temperature; The temperature protection switch module limits the temperature of the pre-charge and discharge control circuit and cuts off the circuit when the temperature reaches a threshold temperature.

10. A pre-discharge control method based on the pre-charge control circuit according to any one of claims 1 to 8, characterized in that: The pre-release control method comprises: The processor MCU controls the second signal generator to generate a PWM signal with an adjustable duty cycle. When the PWM signal is at a high level, the pre-amplifier control module turns on the pre-amplifier loop. When the voltage of the current limiting module reaches the second threshold voltage, the host wake-up module is turned on, and a signal is sent to the processor MCU, and the processor MCU turns on the main release circuit; The current limiting module collects the module temperature and sends it to the processor MCU, and the processor MCU adjusts the duty cycle of the PWM signal according to the module temperature; The temperature protection switch module limits the temperature of the pre-charge and discharge control circuit and cuts off the circuit when the temperature reaches a threshold temperature.

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