Direct-current power supply input circuit and battery management system

Abstract

The utility model relates to the technical field of power electronics, in particular to a direct-current power supply input circuit and a battery management system, the direct-current power supply input circuit comprises an overvoltage detection unit, a driving unit, an anti-reverse connection unit and a soft start protection unit, and when a power supply voltage is greater than a first preset voltage, the overvoltage detection unit outputs a first control signal to the driving unit. The driving unit is switched on and outputs a second control signal when receiving the first control signal. The anti-reverse connection unit is conducted when the anode voltage of the power supply is greater than the cathode voltage of the power supply and the power supply voltage is greater than a second preset voltage, and is cut off when a second control signal is received. The soft start protection unit charges a capacitor in the soft start protection unit when the power supply is powered on, the soft start protection unit is switched on until the voltage of the capacitor is greater than a third preset voltage, and the soft start protection unit is switched off when a second control signal is received. And the functions of overvoltage protection, input power supply reverse connection protection and the like are considered in design, so that the reliability of system operation is improved.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a direct current power supply input circuit and a battery management system. Background Art

[0002] In the application process of battery management system, due to the influence of various reasons such as abnormal power supply voltage, complex electromagnetic environment, illegal operation of construction personnel, thunderstorm weather, etc., overvoltage, undervoltage, overcurrent, reverse polarity or signal interference often occur at the DC power input port, which in turn causes damage to BMS (BATTERY MANAGEMENT SYSTEM) and affects subsequent circuits, reducing the reliability of system operation. Therefore, it is particularly important to design an effective DC port protection circuit. Utility Model Content

[0003] The embodiments of the present application provide a DC power input circuit and a battery management system, which are designed to take into account functions such as overvoltage protection and input power reverse connection protection, thereby improving the reliability of system operation.

[0004] In a first aspect, an embodiment of the present application provides a DC power input circuit, comprising an overvoltage detection unit, a drive unit, an anti-reverse connection unit, and a soft start protection unit; the overvoltage detection unit is connected to the power supply, the overvoltage detection unit is connected to the drive unit, the anti-reverse connection unit and the soft start protection unit are both connected to the drive unit, the anti-reverse connection unit is connected to the soft start protection unit, and the soft start protection unit is also connected to a load; the overvoltage detection unit is used to output a first control signal to the drive unit when the power supply voltage is greater than a first preset voltage; the power supply voltage is the voltage drop between the positive voltage of the power supply and the negative voltage of the power supply; the drive unit is used to turn on when receiving the first control signal and output a second control signal; the anti-reverse connection unit is used to turn on when the positive voltage of the power supply is greater than the negative voltage of the power supply and the power supply voltage is greater than the second preset voltage, and to turn off when receiving the second control signal; the soft start protection unit is used to charge the capacitor of the soft start protection unit when the power supply is powered on, until the voltage of the capacitor is greater than the third preset voltage and then turns on, and to turn off when receiving the second control signal.

[0005] In some embodiments, the overvoltage detection unit includes a resistor R1 and a Zener diode D2; the first end of the resistor R1 is connected to the positive electrode of the power supply and the driving unit, the second end of the resistor R1 is connected to the negative electrode of the Zener diode D2 and the driving unit, and the positive electrode of the Zener diode D2 is connected to the negative electrode of the power supply and the driving unit.

[0006] In some embodiments, the driving unit includes a resistor R2, a resistor R4, a resistor R5, a switch tube Q1, and a switch tube Q2; the first end of the resistor R2 is connected to the overvoltage detection unit, the second end of the resistor R2 is connected to the control end of the switch tube Q1, the second end of the switch tube Q1 is connected to the anti-reverse connection unit and the soft start protection unit, the third end of the switch tube Q1 is connected to the control end of the switch tube Q2 through the resistor R4, the second end of the switch tube Q2 is connected to the anti-reverse connection unit, the third end of the switch tube Q2 is connected to the negative electrode of the power supply, the first end of the resistor R5 is connected to the control end of the switch tube Q2, and the second end of the resistor R5 is connected to the third end of the switch tube Q2.

[0007] In some embodiments, the anti-reverse connection unit includes a switch tube Q3, a voltage-stabilizing diode D4, a resistor R3, and a resistor R6; the control end of the switch tube Q3 is connected to the second end of the resistor R6, the first end of the resistor R6, the cathode of the voltage-stabilizing diode D4, and the driving unit, the first end of the resistor R3 is connected to the positive electrode of the power supply, the second end of the switch tube Q3 is connected to the negative electrode of the power supply, and the third end of the switch tube Q3 is connected to the second end of the resistor R6, the anode of the voltage-stabilizing diode D4, and the soft start protection unit.

[0008] In some embodiments, the soft start protection unit includes a switch tube Q4, a resistor R7, a resistor R8, a capacitor C11, and a diode D3; the control end of the switch tube Q4 is connected to the positive electrode of the diode D3, the first end of the resistor R8 and the driving unit, the negative electrode of the diode D3 is connected to the positive electrode of the power supply and the positive electrode of the load, the first end of the capacitor C11 is connected to the second end of the resistor R8, the second end of the switch tube Q4 is connected to the second end of the capacitor C11, the first end of the resistor R7 and the anti-reverse connection unit, and the third end of the switch tube Q4 is connected to the second end of the resistor R7 and the negative electrode of the load.

[0009] In some embodiments, the DC power input circuit further includes a first filtering unit, which includes an inductor L1, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, and a capacitor C10; the capacitor C3 and the capacitor C4 are connected in series to form a first group of capacitors, the capacitor C5 and the capacitor C6 are connected in series to form a second group of capacitors, the capacitor C7 and the capacitor C8 are connected in series to form a third group of capacitors, and the capacitor C9 and the capacitor C10 are connected in series to form a fourth group of capacitors, a first end of the first group of capacitors is connected to a first end of the second group of capacitors, a second end of the inductor L1, and a positive electrode of the power supply, a second end of the first group of capacitors is connected to a second end of the second group of capacitors, a first end of the inductor L1, and a negative electrode of the power supply, a first end of the third group of capacitors is connected to a first end of the fourth group of capacitors, a third end of the inductor L1, and a positive electrode of the load, and a second end of the third group of capacitors is connected to a second end of the fourth group of capacitors, a fourth end of the inductor L1, and a negative electrode of the load.

[0010] In some embodiments, the DC power input circuit also includes a second filtering unit, which includes capacitor C12, capacitor C13, capacitor C14, and capacitor C15; the first end of the capacitor C12 is connected to the first end of the capacitor C13, the first end of the capacitor C14, the first end of the capacitor C15, the soft start protection unit, and the positive electrode of the load, and the second end of the capacitor C12 is connected to the second end of the capacitor C13, the second end of the capacitor C14, the second end of the capacitor C15, the soft start protection unit, and the negative electrode of the load.

[0011] In some embodiments, the DC power supply input circuit also includes a surge protection unit, which includes a diode D1, a capacitor C1, and a capacitor C2; the first end of the diode D1 is connected to the first end of the capacitor C1, the positive electrode of the power supply, and the overvoltage detection unit, the second end of the diode D1 is connected to the second end of the capacitor C2, the negative electrode of the power supply, and the overvoltage detection unit, and the second end of the capacitor C1 is connected to the first end of the capacitor C2.

[0012] In some embodiments, the DC power input circuit further includes: a fuse protection unit, the fuse protection unit includes a fuse F1; a first end of the fuse F1 is connected to the positive electrode of the power supply, and a second end of the fuse F1 is connected to the overvoltage detection unit.

[0013] In a second aspect, an embodiment of the present application provides a battery management system, which includes the DC power input circuit as described above.

[0014] The embodiment of the present application provides a DC power input circuit, including an overvoltage detection unit, a drive unit, an anti-reverse connection unit, and a soft start protection unit. When the power supply voltage is greater than a first preset voltage, the overvoltage detection unit outputs a first control signal to the drive unit. The drive unit is turned on and outputs a second control signal when it receives the first control signal. The anti-reverse connection unit is turned on when the positive voltage of the power supply is greater than the negative voltage of the power supply and the power supply voltage is greater than the second preset voltage, and is turned off when the second control signal is received. The soft start protection unit charges the capacitor in the soft start protection unit when the power supply is powered on, until the voltage of the capacitor is greater than the third preset voltage, the soft start protection unit is turned on, and is turned off when the second control signal is received. The design takes into account functions such as overvoltage protection and input power reverse connection protection, thereby improving the reliability of system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] One or more embodiments are exemplarily described by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and the figures in the drawings do not constitute proportional limitations unless otherwise stated.

[0016] Figure 1 is a structural block diagram of a DC power input circuit provided in an embodiment of the present application;

[0017] Figure 2 is a structural block diagram of another DC power input circuit provided in an embodiment of the present application;

[0018] Figure 3 It is a circuit structure diagram of a fuse protection unit, a surge protection unit, and a first filtering unit of a DC power supply input circuit provided in an embodiment of the present application;

[0019] Figure 4 It is a circuit structure diagram of an overvoltage detection unit, a drive unit, an anti-reverse connection unit, a soft start protection unit, and a second filtering unit of a DC power supply input circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and in detail in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0021] The technical features involved in the various embodiments of the present application described below do not conflict with each other and can be combined with each other.

[0022] When an element is referred to as being “connected to” another element, it can be directly connected to the other element, or one or more intervening elements may be present therebetween.

[0023] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0024] See also Figure 1 , Figure 1 It is a structural block diagram of a DC power input circuit 100 provided in an embodiment of the present application.

[0025] The embodiment of the present application provides a DC power input circuit 100, including an overvoltage detection unit 40, a drive unit 50, an anti-reverse connection unit 60, and a soft start protection unit 70. The overvoltage detection unit 40 is connected to the power supply, the overvoltage detection unit 40 is connected to the drive unit 50, the anti-reverse connection unit 60 and the soft start protection unit 70 are both connected to the drive unit 50, the anti-reverse connection unit 60 is connected to the soft start protection unit 70, and the soft start protection unit 70 is also connected to the load.

[0026] Specifically, the overvoltage detection unit 40 is used to output a first control signal to the drive unit 50 when the power supply voltage is greater than a first preset voltage. The power supply voltage is the voltage drop between the positive voltage of the power supply and the negative voltage of the power supply. The drive unit 50 is turned on when receiving the first control signal and outputs a second control signal. The anti-reverse connection unit 60 is turned on when the positive voltage of the power supply is greater than the negative voltage of the power supply and the power supply voltage is greater than the second preset voltage, and is turned off when receiving the second control signal. The soft start protection unit 70 charges the capacitor in the soft start protection unit 70 when the power supply is powered on, until the voltage of the capacitor is greater than the third preset voltage, the soft start protection unit 70 is turned on, and is turned off when receiving the second control signal.

[0027] The first control signal is a signal for turning on the driving unit 50, and the second control signal is a signal for turning off the anti-reverse connection unit 60 and the soft start protection unit 70. The specific values ​​of the first preset voltage, the second preset voltage and the third preset voltage are determined by the parameters of each component of the circuit and the connection relationship between the components, and are not specifically limited here.

[0028] The embodiment of the present application provides a DC power input circuit 100, including an overvoltage detection unit 40, a drive unit 50, an anti-reverse connection unit 60, and a soft start protection unit 70. When the power supply voltage is greater than the first preset voltage, the overvoltage detection unit 40 outputs a first control signal to the drive unit 50. The drive unit 50 is turned on and outputs a second control signal when receiving the first control signal. The anti-reverse connection unit 60 is turned on when the positive voltage of the power supply is greater than the negative voltage of the power supply and the power supply voltage is greater than the second preset voltage, and is turned off when receiving the second control signal. The soft start protection unit 70 charges the capacitor in the soft start protection unit 70 when the power supply is powered on, until the voltage of the capacitor is greater than the third preset voltage, the soft start protection unit 70 is turned on, and is turned off when receiving the second control signal. The design takes into account functions such as overvoltage protection and input power reverse connection protection, thereby improving the reliability of system operation.

[0029] See also Figure 2 , Figure 2 It is a structural block diagram of another DC power input circuit 100 provided in an embodiment of the present application.

[0030] In some embodiments, the DC power input circuit 100 further includes a fuse protection unit 10, which is connected in series to the positive electrode of the power supply. When the current input by the power supply is too large, the fuse protection unit 10 will cut off the circuit path.

[0031] In some embodiments, the DC power input circuit 100 further includes a surge protection unit 20. A first end of the surge protection unit 20 is connected to the positive electrode of the current, and a second end of the surge protection unit 20 is connected to the negative electrode of the power supply. The surge protection unit 20 is used to absorb the energy of the input differential mode surge to protect the subsequent circuit.

[0032] In some embodiments, the DC power input circuit 100 further includes a first filtering unit 30, a first end of the first filtering unit 30 is connected to the positive electrode of the power supply, a second end of the first filtering unit 30 is connected to the positive electrode of the load, a third end of the first filtering unit 30 is connected to the negative electrode of the power supply, and a fourth end of the first filtering unit 30 is connected to the negative electrode of the load. The first filtering unit 30 is used to filter the input clutter.

[0033] In some embodiments, the DC power input circuit 100 further includes a second filtering unit 80, wherein a first end of the second filtering unit 80 is connected to the positive electrode of the load, and a second end of the first filtering unit 80 is connected to the negative electrode of the load. The second filtering unit 80 is used to filter the clutter output to the load.

[0034] See also Figure 3 , Figure 3It is a circuit structure diagram of a fuse protection unit 10, a surge protection unit 20, and a first filtering unit 30 of a DC power input circuit 100 provided in an embodiment of the present application.

[0035] In some embodiments, the fuse protection unit 10 includes a fuse F1. Specifically, a first end of the fuse F1 is connected to the positive electrode of the power supply, and a second end of the fuse F1 is connected to the overvoltage detection unit 40. When the current in the fuse F1 is too large, the fuse F1 will be blown, thereby disconnecting the power supply to protect the subsequent circuit from being damaged.

[0036] In some embodiments, the surge protection unit 20 includes a diode D1, a capacitor C1, and a capacitor C2. Specifically, the first end of the diode D1 is connected to the first end of the capacitor C1, the positive electrode of the power supply, and the overvoltage detection unit 40, the second end of the diode D1 is connected to the second end of the capacitor C2, the negative electrode of the power supply, and the overvoltage detection unit 40, and the second end of the capacitor C1 is connected to the first end of the capacitor C2. The diode D1 is a transient suppression diode. The transient suppression diode can effectively absorb the energy of the input differential mode surge to protect the subsequent circuit.

[0037] In some embodiments, the first filtering unit 30 includes an inductor L1, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, and a capacitor C10. Specifically, the capacitor C3 and the capacitor C4 are connected in series to form a first group of capacitors, the capacitor C5 and the capacitor C6 are connected in series to form a second group of capacitors, the capacitor C7 and the capacitor C8 are connected in series to form a third group of capacitors, the capacitor C9 and the capacitor C10 are connected in series to form a fourth group of capacitors, the first end of the first group of capacitors is connected to the first end of the second group of capacitors, the second end of the inductor L1, and the positive electrode of the power supply, the second end of the first group of capacitors is connected to the second end of the second group of capacitors, the first end of the inductor L1, and the negative electrode of the power supply, the first end of the third group of capacitors is connected to the first end of the fourth group of capacitors, the third end of the inductor L1, and the positive electrode of the load, and the second end of the third group of capacitors is connected to the second end of the fourth group of capacitors, the fourth end of the inductor L1, and the negative electrode of the load. Among them, the capacitors C3, C4, C5, C6, C7, C8, C9, and C10 realize differential mode filtering, and the inductor L1 is a common mode inductor. The structure of the first filter unit 30 can realize EMC (Electro Magnetic Compatibility) filtering.

[0038] See also Figure 4 , Figure 4 It is a circuit structure diagram of an overvoltage detection unit 40, a drive unit 50, an anti-reverse connection unit 60, a soft start protection unit 70, and a second filtering unit 80 of a DC power input circuit 100 provided in an embodiment of the present application.

[0039] In some embodiments, the second filtering unit 80 includes a capacitor C12, a capacitor C13, a capacitor C14, and a capacitor C15. Specifically, a first end of the capacitor C12 is connected to a first end of the capacitor C13, a first end of the capacitor C14, a first end of the capacitor C15, the soft start protection unit 70, and a positive electrode of the load, and a second end of the capacitor C12 is connected to a second end of the capacitor C13, a second end of the capacitor C14, a second end of the capacitor C15, the soft start protection unit 70, and a negative electrode of the load.

[0040] In some embodiments, the overvoltage detection unit 40 includes a resistor R1 and a voltage regulator diode D2. Specifically, the first end of the resistor R1 is connected to the positive electrode of the power supply and the driving unit 50, the second end of the resistor R1 is connected to the negative electrode of the voltage regulator diode D2 and the driving unit 50, and the positive electrode of the voltage regulator diode D2 is connected to the negative electrode of the power supply and the driving unit 50. The voltage regulator diode D2 is a Zener voltage regulator diode.

[0041] In some embodiments, the driving unit 50 includes a resistor R2, a resistor R4, a resistor R5, a switch tube Q1, and a switch tube Q2. Specifically, the first end of the resistor R2 is connected to the overvoltage detection unit 40, the second end of the resistor R2 is connected to the control end of the switch tube Q1, the second end of the switch tube Q1 is connected to the anti-reverse connection unit 60 and the soft start protection unit 70, the third end of the switch tube Q1 is connected to the control end of the switch tube Q2 through the resistor R4, the second end of the switch tube Q2 is connected to the anti-reverse connection unit 60, the third end of the switch tube Q2 is connected to the negative electrode of the power supply, the first end of the resistor R5 is connected to the control end of the switch tube Q2, and the second end of the resistor R5 is connected to the third end of the switch tube Q2. In some embodiments, the switch tube Q1 is a PNP type triode, the base of the switch tube Q1 is the control end of the switch tube Q1, the emitter of the switch tube Q1 is the second end of the switch tube Q2, and the collector of the switch tube Q1 is the third end of the switch tube Q1. The switch tube Q2 is an NPN transistor, the base of the switch tube Q2 is the control end of the switch tube Q2, the collector of the switch tube Q2 is the second end of the switch tube Q2, and the emitter of the switch tube Q2 is the third end of the switch tube Q2.

[0042] In some embodiments, the anti-reverse connection unit 60 includes a switch tube Q3, a voltage stabilizing diode D4, a resistor R3, and a resistor R6. Specifically, the control end of the switch tube Q3 is connected to the second end of the resistor R6, the first end of the resistor R6, the cathode of the voltage stabilizing diode D4, and the driving unit 50, the first end of the resistor R3 is connected to the anode of the power supply, the second end of the switch tube Q3 is connected to the cathode of the power supply, and the third end of the switch tube Q3 is connected to the second end of the resistor R6, the anode of the voltage stabilizing diode D4, and the soft start protection unit 70. In some embodiments, the switch tube Q3 is an NMOS tube, the gate of the switch tube Q3 is the control end of the switch tube Q3, the drain of the switch tube Q3 is the second end of the switch tube Q3, and the source of the switch tube Q3 is the third end of the switch tube Q.

[0043] In some embodiments, the soft start protection unit 70 includes a switch tube Q4, a resistor R7, a resistor R8, a capacitor C11, and a diode D3. Specifically, the control end of the switch tube Q4 is connected to the positive electrode of the diode D3, the first end of the resistor R8, and the driving unit 50, the negative electrode of the diode D3 is connected to the positive electrode of the power supply and the positive electrode of the load, the first end of the capacitor C11 is connected to the second end of the resistor R8, the second end of the switch tube Q4 is connected to the second end of the capacitor C11, the first end of the resistor R7, and the anti-reverse connection unit 60, and the third end of the switch tube Q4 is connected to the second end of the resistor R7 and the negative electrode of the load. In some embodiments, the switch tube Q4 is an NMOS tube, the gate of the switch tube Q4 is the control end of the switch tube Q4, the source of the switch tube Q4 is the second end of the switch tube Q4, and the drain of the switch tube Q4 is the third end of the switch tube Q4.

[0044] In this embodiment, for the overvoltage detection unit 40, when the power supply voltage is greater than the first preset voltage and the voltage across the Zener diode D2 is greater than the Zener voltage of the Zener diode D2, the current of the Zener diode D2 increases, causing the switch tube Q1 to be turned on. After the switch tube Q1 is turned on, the switch tube Q2 is driven to be turned on. After the switch tube Q2 is turned on, the gate-source voltage VGS of the switch tubes Q3 and Q4 is less than the turn-on voltage of the two switch tubes, thereby causing the switch tubes Q3 and Q4 to be turned off, thereby protecting the subsequent circuit.

[0045] For the anti-reverse connection unit 60, when the positive voltage of the power input is greater than the negative voltage and the power voltage is greater than the second preset voltage, the divided voltage of the resistor R6 in the series circuit of the resistor R6 and the resistor R3 is greater than the turn-on voltage of the switch tube Q3, so that the switch tube Q3 is turned on and the subsequent circuit functions normally; otherwise, the switch tube Q3 is turned off to prevent the power supply polarity of the subsequent circuit from reversing.

[0046] For the soft start protection unit 70, when the capacitor is powered on, the voltage of the capacitor C11 rises slowly. When the voltage of the capacitor C11 is less than the third preset voltage, the gate-source voltage VGS of the switch tube Q4 is less than the turn-on voltage of the switch tube Q4, and the electrolytic capacitor of the subsequent stage is charged through the resistor R7 with current limiting. When the voltage of the capacitor C11 is greater than the third preset voltage, the gate-source voltage VGS of the switch tube Q4 is greater than the turn-on voltage of the switch tube Q4, the switch tube Q4 is turned on, and the circuit is in a low resistance state. In addition, when the power is off, the diode D3 quickly discharges the charge of the capacitor C11 to ensure the normal operation of the soft start when the power is turned on again.

[0047] The embodiment of the present application provides a DC power input circuit 100, including an overvoltage detection unit 40, a drive unit 50, an anti-reverse connection unit 60, and a soft start protection unit 70. When the power supply voltage is greater than the first preset voltage, the overvoltage detection unit 40 outputs a first control signal to the drive unit 50. The drive unit 50 is turned on and outputs a second control signal when receiving the first control signal. The anti-reverse connection unit 60 is turned on when the positive voltage of the power supply is greater than the negative voltage of the power supply and the power supply voltage is greater than the second preset voltage, and is turned off when the second control signal is received. The soft start protection unit 70 charges the capacitor in the soft start protection unit 70 when the power supply is powered on, until the voltage of the capacitor is greater than the third preset voltage, the soft start protection unit 70 is turned on, and is turned off when the second control signal is received.

[0048] The DC power input circuit provided in the embodiment of the present application has anti-reverse connection and soft start functions, and at the same time adds surge protection and EMC (Electro Magnetic Compatibility) filtering, and further adds an overvoltage protection circuit, so that the circuit can take into account EMC protection, lightning surge protection, input power reverse connection protection and overvoltage protection functions, thereby improving the safety and stability of the circuit.

[0049] A battery management system includes the DC power input circuit 100 as described above. The specific structure of the DC power input circuit 100 can be referred to the above embodiment, and will not be described in detail here.

[0050] Among them, the battery management system can be an active balancing battery management system. The power input circuit of the active balancing battery management system has the function of bidirectional energy flow of energy input (charging) and output (discharging), and has an input reverse connection protection function, which can realize both the reverse connection protection function and the bidirectional energy flow with very little loss.

[0051] The existing active balancing adopts a switching power supply solution, so the power input circuit of the battery management system has good EMC filtering capability, but requires a larger capacitor, which will cause excessive current impact when the external power supply is powered on. Therefore, the embodiment of the present application adopts a MOS switch tube to achieve soft start, prevent the startup current from being too large, and provide a larger capacitor capacity for active balancing.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the idea of ​​the present application, the technical features in the above embodiments or different embodiments may also be combined, and there are many other changes in different aspects of the present application as described above, which are not provided in detail for the sake of simplicity. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A DC power input circuit, It is characterized in that Including overvoltage detection unit, drive unit, anti-reverse connection unit, and soft start protection unit; The overvoltage detection unit is connected to the power supply, the overvoltage detection unit is connected to the driving unit, the anti-reverse connection unit and the soft start protection unit are both connected to the driving unit, the anti-reverse connection unit is connected to the soft start protection unit, and the soft start protection unit is also connected to the load; The overvoltage detection unit is used to output a first control signal to the driving unit when the power supply voltage is greater than a first preset voltage; the power supply voltage is a voltage drop between a positive voltage of the power supply and a negative voltage of the power supply; The driving unit is configured to be turned on upon receiving the first control signal and output a second control signal; The anti-reverse connection unit is used to be turned on when the positive voltage of the power supply is greater than the negative voltage of the power supply and the power supply voltage is greater than a second preset voltage, and is turned off when receiving the second control signal; The soft start protection unit is used to charge the capacitor of the soft start protection unit when the power supply is powered on, and is turned on when the voltage of the capacitor is greater than a third preset voltage, and is turned off when the second control signal is received.

2. The DC power input circuit according to claim 1, It is characterized in that The overvoltage detection unit includes a resistor R1 and a voltage stabilizing diode D2; The first end of the resistor R1 is connected to the positive electrode of the power supply and the driving unit, the second end of the resistor R1 is connected to the negative electrode of the voltage zener diode D2 and the driving unit, and the positive electrode of the voltage zener diode D2 is connected to the negative electrode of the power supply and the driving unit.

3. The DC power input circuit according to claim 1, It is characterized in that The driving unit includes a resistor R2, a resistor R4, a resistor R5, a switch tube Q1, and a switch tube Q2; The first end of the resistor R2 is connected to the overvoltage detection unit, the second end of the resistor R2 is connected to the control end of the switch tube Q1, the second end of the switch tube Q1 is connected to the anti-reverse connection unit and the soft start protection unit, the third end of the switch tube Q1 is connected to the control end of the switch tube Q2 through the resistor R4, the second end of the switch tube Q2 is connected to the anti-reverse connection unit, the third end of the switch tube Q2 is connected to the negative electrode of the power supply, the first end of the resistor R5 is connected to the control end of the switch tube Q2, and the second end of the resistor R5 is connected to the third end of the switch tube Q2.

4. The DC power input circuit according to claim 1, It is characterized in that The anti-reverse connection unit includes a switch tube Q3, a voltage stabilizing diode D4, a resistor R3, and a resistor R6; The control end of the switch tube Q3 is connected to the second end of the resistor R6, the first end of the resistor R6, the cathode of the voltage-stabilizing diode D4 and the driving unit, the first end of the resistor R3 is connected to the anode of the power supply, the second end of the switch tube Q3 is connected to the cathode of the power supply, and the third end of the switch tube Q3 is connected to the second end of the resistor R6, the anode of the voltage-stabilizing diode D4 and the soft start protection unit.

5. The DC power input circuit according to claim 1, It is characterized in that The soft start protection unit includes a switch tube Q4, a resistor R7, a resistor R8, a capacitor C11, and a diode D3; The control end of the switch tube Q4 is connected to the positive electrode of the diode D3, the first end of the resistor R8 and the driving unit, the negative electrode of the diode D3 is connected to the positive electrode of the power supply and the positive electrode of the load, the first end of the capacitor C11 is connected to the second end of the resistor R8, the second end of the switch tube Q4 is connected to the second end of the capacitor C11, the first end of the resistor R7 and the anti-reverse connection unit, and the third end of the switch tube Q4 is connected to the second end of the resistor R7 and the negative electrode of the load.

6. The DC power input circuit according to claim 1, It is characterized in that The DC power input circuit further includes a first filtering unit, which includes an inductor L1, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, and a capacitor C10; The capacitor C3 and the capacitor C4 are connected in series to form a first group of capacitors, the capacitor C5 and the capacitor C6 are connected in series to form a second group of capacitors, the capacitor C7 and the capacitor C8 are connected in series to form a third group of capacitors, and the capacitor C9 and the capacitor C10 are connected in series to form a fourth group of capacitors. The first end of the first group of capacitors is connected to the first end of the second group of capacitors, the second end of the inductor L1, and the positive electrode of the power supply, the second end of the first group of capacitors is connected to the second end of the second group of capacitors, the first end of the inductor L1, and the negative electrode of the power supply, the first end of the third group of capacitors is connected to the first end of the fourth group of capacitors, the third end of the inductor L1, and the positive electrode of the load, and the second end of the third group of capacitors is connected to the second end of the fourth group of capacitors, the fourth end of the inductor L1, and the negative electrode of the load.

7. The DC power input circuit according to claim 1, It is characterized in that The DC power input circuit further includes a second filtering unit, which includes a capacitor C12, a capacitor C13, a capacitor C14, and a capacitor C15; The first end of the capacitor C12 is connected to the first end of the capacitor C13, the first end of the capacitor C14, the first end of the capacitor C15, the soft start protection unit and the positive electrode of the load, and the second end of the capacitor C12 is connected to the second end of the capacitor C13, the second end of the capacitor C14, the second end of the capacitor C15, the soft start protection unit and the negative electrode of the load.

8. The DC power input circuit according to claim 1, It is characterized in that The DC power input circuit further includes a surge protection unit, which includes a diode D1, a capacitor C1, and a capacitor C2; The first end of the diode D1 is connected to the first end of the capacitor C1, the positive electrode of the power supply and the overvoltage detection unit, the second end of the diode D1 is connected to the second end of the capacitor C2, the negative electrode of the power supply and the overvoltage detection unit, and the second end of the capacitor C1 is connected to the first end of the capacitor C2.

9. The DC power input circuit according to any one of claims 1 to 8, It is characterized in that The DC power input circuit also includes a fuse protection unit, and the fuse protection unit includes a fuse F1; The first end of the fuse F1 is connected to the positive electrode of the power source, and the second end of the fuse F1 is connected to the overvoltage detection unit.

10. A battery management system, It is characterized in that The battery management system comprises a DC power input circuit as described in any one of claims 1-9.

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