Starting circuit of battery pack and electronic equipment

Abstract

The embodiment of the utility model discloses a starting circuit of a battery pack and electronic equipment, and relates to the field of circuits. A starting circuit of a battery pack is applied to the battery pack composed of a plurality of batteries connected in series and is characterized by comprising a controller, a first resistor, a second resistor, a first diode and a first switching tube, a second switch tube, a third resistor, a fourth resistor and a second diode; the circuit comprises a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube, a fifth MOS tube, a sixth MOS tube, a first inductor, a second inductor, a first capacitor, a second capacitor, a fifth resistor, a sixth resistor, a third diode and a fourth diode. Through the well-designed circuit and control strategy, the gate voltage on the switch tube is gradually increased, and the drain-source voltage is slowly increased, so that the effect of flexibly starting the load is achieved. The flexible starting mode not only can effectively protect the load from current impact, but also can improve the stability and reliability of the system.

Description

Technical Field

[0001] The utility model relates to the field of circuits, in particular to a starting circuit of a battery pack and electronic equipment. Background Art

[0002] Electric motorcycles and electric bicycles are increasingly using 48V and 60V batteries. For safety reasons, the new national standard requires the battery management system to disconnect the high-voltage end when the battery is not in use or protected. In this case, using NMOS on the high-voltage side is the best solution to ensure safe disconnection.

[0003] Since NMOS needs to provide a positive gate voltage to turn on, and this voltage must be generated inside the power management chip, it is difficult to achieve safe, controllable and convenient implementation, which increases the difficulty of chip design. When the NMOS feed is turned on, a large impact current will be generated due to the large capacitance of the external inverter circuit. Utility Model Content

[0004] The starting circuit and electronic device provided in the embodiments of the present application can solve the problem of large current impact when starting the load in the prior art. The technical solution is as follows:

[0005] In a first aspect, an embodiment of the present application provides a startup circuit of a battery pack, which is applied to a battery pack composed of a plurality of batteries connected in series, and is characterized in that it includes: a controller, a first resistor, a second resistor, a first diode, and a first switch tube; a second switch tube, a third resistor, a fourth resistor, and a second diode; a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube, a fifth MOS tube, a sixth MOS tube, a first inductor, a second inductor, a first capacitor, a second capacitor, a fifth resistor, a sixth resistor, a third diode, and a fourth diode;

[0006] The first end of the first resistor is connected to the gate of the first switch tube; the second end of the first resistor is respectively connected to the cathode of the first diode, the second end of the second resistor, the second end of the first capacitor, the cathode of the third diode, and the first end of the fifth resistor; the first end of the second resistor is respectively connected to the positive electrode of the battery pack, the first end of the first capacitor, the anode of the first diode, and the source of the first switch tube;

[0007] The second end of the fifth resistor is connected to the source of the first MOS tube; the anode of the third diode is respectively connected to the source of the second MOS tube and the first end of the first inductor; the drains of the first MOS tube and the second MOS tube are respectively connected to the negative electrode of the battery pack; the second end of the first inductor is connected to the drain of the third MOS tube; the drain of the first switch tube is respectively connected to the drain of the second switch tube, the charging port, the source of the third MOS tube, and the source of the fourth MOS tube;

[0008] The gate of the second switch tube is connected to the first end of the third resistor; the second end of the third resistor is respectively connected to the second end of the fourth resistor, the cathode of the second diode, the cathode of the fourth diode, the first end of the sixth resistor, and the first end of the second capacitor; the second end of the second capacitor is respectively connected to the source of the second switch tube, the first end of the fourth resistor, the anode of the second diode, and the load port;

[0009] The anode of the fourth diode is respectively connected to the second end of the second inductor and the source of the fifth MOS tube, the first end of the second inductor is connected to the drain of the fourth MOS tube; the second end of the sixth resistor is connected to the source of the sixth MOS tube; the drains of the fifth MOS tube and the sixth MOS tube are respectively connected to the negative electrode of the battery pack; the negative electrode of the battery pack is grounded;

[0010] The gates of the first MOS tube, the second MOS tube, the third MOS tube, the fourth MOS tube, the fifth MOS tube and the sixth MOS tube are respectively connected to the controller.

[0011] In a second aspect, the present application provides an electronic device, including the starting circuit of the present application.

[0012] The beneficial effects brought about by the technical solutions provided by some embodiments of the present application include at least:

[0013] Through the circuit and control strategy of the present application, the gate voltage of the switch tube is gradually increased and the drain-source voltage is slowly increased, thereby achieving the effect of flexible load startup. This flexible startup method can not only effectively protect the load from current shock, but also improve the stability and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a circuit structure diagram of the starting circuit of the battery pack provided in this application. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0017] See also Figure 1 As shown, the utility model provides a schematic structural diagram of a starting circuit of a battery pack according to an embodiment. The starting circuit is applied to a battery pack BAT formed by a plurality of batteries connected in series. The voltage value of the battery pack BAT can be 24V or 48V.

[0018] The startup circuit includes: a controller ( Figure 1 The controller plays a control role and can be implemented in at least one hardware form of digital signal processing (DSP), field programmable gate array (FPGA), and programmable logic array (PLA).

[0019] The connection relationship of the above components is as follows: the first end of the first resistor R1 is connected to the gate of the first switch tube Q1; the second end of the first resistor R1 is respectively connected to the cathode of the first diode D1, the second end of the second resistor R2, the second end of the first capacitor C1, the cathode of the third diode D3, and the first end of the fifth resistor R5. The first end of the second resistor R2 is respectively connected to the positive electrode of the battery pack BAT, the first end of the first capacitor C1, the anode of the first diode D1, and the source of the first switch tube Q1.

[0020] The second end of the fifth resistor R5 is connected to the source of the first MOS tube M1; the anode of the third diode D3 is connected to the source of the second MOS tube M2 and the first end of the first inductor L1 respectively. The drains of the first MOS tube M1 and the second MOS tube M2 are connected to the negative electrode of the battery pack BAT respectively. The second end of the first inductor L1 is connected to the drain of the third MOS tube M3; the drain of the first switch tube Q1 is connected to the drain of the second switch tube Q2, the charging port, the source of the third MOS tube M3, and the source of the fourth MOS tube M4 respectively.

[0021] The gate of the second switch tube Q2 is connected to the first end of the third resistor R3. The second end of the third resistor R3 is respectively connected to the second end of the fourth resistor R4, the cathode of the second diode D3, the cathode of the fourth diode D4, the first end of the sixth resistor R6, and the first end of the second capacitor C2. The second end of the second capacitor C2 is respectively connected to the source of the second switch tube Q2, the first end of the fourth resistor R4, the anode of the second diode D2, and the load port.

[0022] The anode of the fourth diode D4 is respectively connected to the second end of the second inductor L2 and the source of the fifth MOS tube M5, and the first end of the second inductor L2 is connected to the drain of the fourth MOS tube M4; the second end of the sixth resistor R6 is connected to the source of the sixth MOS tube M6; the drains of the fifth MOS tube M5 and the sixth MOS tube M6 are respectively connected to the negative electrode of the battery pack BAT, and the negative electrode of the battery pack BAT is grounded.

[0023] The gates of the first MOS tube M1, the second MOS tube M2, the third MOS tube M3, the fourth MOS tube M4, the fifth MOS tube M5 and the sixth MOS tube M6 are respectively connected to the controller, and the controller sends PWM signals to the first MOS tube M1 to the sixth MOS tube M6 through the PWM port to control the on and off of each MOS tube.

[0024] The working principle of the starting circuit of the present application is: the controller determines the working mode, and the working modes are charging mode and power supply mode. The charging mode means charging the battery pack through the charging port using an external power supply, and the power supply mode means using the battery pack to power the load connected to the load port.

[0025] In the power supply mode, when the controller receives a turn-on instruction for the second switch tube Q2, it controls the fourth MOS tube M4 to be in the on state. At the same time, the controller sends a PWM signal to the fifth MOS tube M5 to make the fifth MOS tube M5 turn on and off periodically. When the fifth MOS tube M5 is in the on state, the current from the battery pack BAT will flow through the second inductor L2. When the fifth MOS tube M5 is in the off state, since the current of the inductor L2 cannot disappear immediately, it will charge the second capacitor C2 through the fourth diode D4. In this process, the controller collects the voltage value across the second capacitor C2 and uses a closed-loop control method to adjust the duty cycle of the PWM signal sent to the fifth MOS tube M5. The gradual increase in the duty cycle will gradually increase the voltage on the gate voltage of the second switch tube Q2, thereby controlling its drain-source voltage to gradually change, and realizing the flexible connection of the load switch. When the controller receives a turn-off instruction for the second switch tube Q2, it will control the fourth MOS tube M4 and the fifth MOS tube M5 to be in the off state. At the same time, the controller will control the sixth MOS tube M6 to be in the on state. Due to the conduction of the sixth MOS tube M6 , the charge stored in the second capacitor C2 is quickly discharged, thereby realizing the rapid shut-off of the second switch tube Q2 .

[0026] By controlling the duty cycle of the PWM signal of the fifth MOS tube M5, the present application can accurately control the gate voltage and drain-source voltage of the second switch tube Q2, realize the flexible connection of the load switch, and reduce the impact on the load. By turning on the sixth MOS tube M6, the charge in the second capacitor C2 can be quickly discharged, thereby realizing the rapid shutdown of the second switch tube Q2. The controller performs closed-loop control according to the collected voltage value to ensure stable operation of the system. The circuit system of the present application realizes accurate management of the battery pack power supply mode through fine MOS tube control and closed-loop control strategy, and provides a stable and controllable power supply for the load.

[0027] In the charging mode, after the controller receives the on-instruction for the first switch tube Q1, the controller controls the third MOS tube M3 to be in the on-state, and then controls the second MOS tube M2 to be periodically turned on and off through the PWM signal. When the second MOS tube M2 is in the on-state, the battery pack BAT flows through the first inductor L1. When the second MOS tube M2 is in the off-state, the current of the first inductor L1 charges the first capacitor C1 through the third diode D3. In the process of charging the first capacitor C1, the controller collects the voltage across the first capacitor C1 and uses a closed-loop control method to adjust the duty cycle of the PWM signal output to the gate of the second MOS tube M2. The process of the duty cycle changing from small to large causes the gate voltage to gradually increase, so as to achieve the purpose of gradually increasing the drain-source voltage of the first switch tube Q1, thereby realizing the flexible connection between the charger and the battery pack, and avoiding the charging current from causing a large impact on the battery pack.

[0028] When the controller receives a shutdown instruction for the first switch tube Q1, it controls the third MOS tube to be in the M3 shutdown state, the second MOS tube M2 to be in the disconnected state, and the first MOS tube M1 to be in the on state, so that the charge stored in the first capacitor C1 can be quickly discharged, and the first switch tube Q1 can be quickly turned off.

[0029] In some embodiments of the present application, the process in which the controller uses a closed-loop method to adjust the duty cycle of the PWM signal input to the fifth MOS tube includes:

[0030] The controller continuously monitors the voltage value across the second capacitor C2 through an internal ADC (analog-to-digital converter) or other voltage detection circuit. In the power supply mode, the controller sets a target voltage value according to the system requirements and preset parameters. This target voltage value is usually the voltage level expected to be reached across the second capacitor C2. The controller compares the actual voltage value across the second capacitor C2 collected with the set target voltage value and calculates the difference (i.e., error). According to the calculated error value, the controller adjusts the duty cycle of the PWM signal sent to the fifth MOS tube M5. If the actual voltage is lower than the target voltage, the controller will increase the duty cycle of the PWM signal to increase the conduction time of the fifth MOS tube M5, thereby increasing the charging current of the battery pack BAT to the second capacitor C2, so that the actual voltage rises. If the actual voltage is higher than the target voltage, the controller will reduce the duty cycle of the PWM signal to reduce the conduction time of the fifth MOS tube M5, reduce the charging current, and reduce the actual voltage. The controller will continue to repeat the above-mentioned process of voltage acquisition, error calculation and PWM signal duty cycle adjustment until the voltage value across the second capacitor C2 stabilizes near the target voltage value. This process of continuously adjusting the control signal (PWM duty cycle) through the feedback signal (i.e., voltage error) is the core of closed-loop control.

[0031] In some embodiments of the present application, the first diode D1 and the second diode D2 are Zener diodes. The main function is to provide a stable voltage reference in the circuit. The working principle of the Zener diode is based on the reverse breakdown phenomenon. When the reverse voltage across the Zener diode increases to a certain value (called the Zener voltage or breakdown voltage), it will suddenly start to conduct, the current will increase significantly, but the voltage will remain almost unchanged. This characteristic allows the Zener diode to be used as a stable voltage source in the circuit, and the output voltage can be kept stable regardless of how the input voltage or load current changes.

[0032] In some embodiments of the present application, the first capacitor C1 and the second capacitor C2 are electrolytic capacitors, the first end of the first capacitor C1 is a negative electrode -, and the second end is a positive electrode +; the first end of the second capacitor C2 is a positive electrode +, and the second end is a negative electrode -. An electrolytic capacitor is a capacitor with polarity, and its positive electrode (+) and negative electrode (-) cannot be interchanged.

[0033] In some embodiments of the present application, the first capacitor C1, the second capacitor C2, the third diode D3, the fourth diode D4, the fifth resistor R5, the sixth resistor R6, the first MOS tube M1, the second MOS tube M2, the third MOS tube M3, the fourth MOS tube M4, the fifth MOS tube M5, the sixth MOS tube M6, and the controller are packaged in the chip. The first capacitor C1, the second capacitor C2, the third diode D3, the fourth diode D4, the fifth resistor R5, the sixth resistor R6, the first MOS tube M1 to the sixth MOS tube M6 and the controller are packaged in the chip, which greatly improves the integration of the circuit. For example: the above period is packaged in the BMS chip. This integrated design makes the circuit more compact, reduces the occupied space of the circuit board, and reduces the complexity of the external connection and potential interference sources. The connection between the components packaged inside the chip and the controller is tighter, reducing the performance loss and noise interference that may be caused by the external connection. The packaged chip can be specially tested and optimized to ensure that its performance is stable and reliable. The packaged chip can be produced as a standardized module, which simplifies the production process and improves production efficiency. During repair and replacement, only the entire chip needs to be replaced without checking and replacing internal components one by one, reducing the complexity and cost of maintenance.

[0034] This application has the following beneficial effects:

[0035] Through the carefully designed circuit and control strategy, the gate voltage on the switch tube is gradually increased and the drain-source voltage is slowly increased, thus achieving the effect of soft start-up of the load. This soft start-up method can not only effectively protect the load from current shock, but also improve the stability and reliability of the system.

[0036] The electronic device provided in the embodiments of the present application includes but is not limited to communication equipment, terminal equipment, computer equipment, etc. In addition to the above-mentioned starting circuit, the electronic device may also include: a housing for accommodating various components, a display screen and an input device (for example: a keyboard, a mouse or a touch screen), etc.

[0037] The above-described implementation methods do not constitute a limitation on the protection scope of the technical solution. Any modification, equivalent replacement and improvement made within the spirit and principle of the above-described implementation methods shall be included in the protection scope of the technical solution.

Claims

1. A battery pack starting circuit, applied to a battery pack consisting of a plurality of batteries connected in series, characterized in that: include: A controller, a first resistor, a second resistor, a first diode, and a first switch tube; The second switch tube, the third resistor, the fourth resistor, and the second diode; the first MOS tube, the second MOS tube, the third MOS tube, the fourth MOS tube, the fifth MOS tube, the sixth MOS tube, the first inductor, the second inductor, the first capacitor, the second capacitor, the fifth resistor, the sixth resistor, the third diode, and the fourth diode; The first end of the first resistor is connected to the gate of the first switch tube; the second end of the first resistor is respectively connected to the cathode of the first diode, the second end of the second resistor, the second end of the first capacitor, the cathode of the third diode, and the first end of the fifth resistor; the first end of the second resistor is respectively connected to the positive electrode of the battery pack, the first end of the first capacitor, the anode of the first diode, and the source of the first switch tube; The second end of the fifth resistor is connected to the source of the first MOS tube; the anode of the third diode is respectively connected to the source of the second MOS tube and the first end of the first inductor; the drains of the first MOS tube and the second MOS tube are respectively connected to the negative electrode of the battery pack; the second end of the first inductor is connected to the drain of the third MOS tube; the drain of the first switch tube is respectively connected to the drain of the second switch tube, the charging port, the source of the third MOS tube, and the source of the fourth MOS tube; The gate of the second switch tube is connected to the first end of the third resistor; the second end of the third resistor is respectively connected to the second end of the fourth resistor, the cathode of the second diode, the cathode of the fourth diode, the first end of the sixth resistor, and the first end of the second capacitor; the second end of the second capacitor is respectively connected to the source of the second switch tube, the first end of the fourth resistor, the anode of the second diode, and the load port; The anode of the fourth diode is respectively connected to the second end of the second inductor and the source of the fifth MOS tube, the first end of the second inductor is connected to the drain of the fourth MOS tube; the second end of the sixth resistor is connected to the source of the sixth MOS tube; the drains of the fifth MOS tube and the sixth MOS tube are respectively connected to the negative electrode of the battery pack; the negative electrode of the battery pack is grounded; The gates of the first MOS tube, the second MOS tube, the third MOS tube, the fourth MOS tube, the fifth MOS tube and the sixth MOS tube are respectively connected to the controller.

2. The circuit according to claim 1, characterized in that The first diode and the second diode are Zener diodes.

3. The circuit according to claim 2, characterized in that The first capacitor and the second capacitor are electrolytic capacitors, the first end of the first capacitor is a negative electrode, and the second end is a positive electrode; the first end of the second capacitor is a positive electrode, and the second end is a negative electrode.

4. The circuit according to claim 1, 2 or 3, characterized in that: The first capacitor, the second capacitor, the third diode, the fourth diode, the fifth resistor, the sixth resistor, the first MOS transistor, the second MOS transistor, the third MOS transistor, the fourth MOS transistor, the fifth MOS transistor, the sixth MOS transistor, and the controller are packaged in a chip.

5. An electronic device, characterized in that: The invention comprises a starting circuit and a battery pack according to any one of claims 1 to 4.

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