Driving circuit and direct current charging pile

Abstract

The embodiment of the application provides a driving circuit and a direct current charging pile, the driving circuit comprises a switching unit, a driving signal input end, an energy storage unit, the switching unit has a control end and a conduction end; the driving signal input end is connected with the control end and is used for inputting a driving signal; the energy storage unit comprises a first voltage end and a second voltage end, the first voltage end is connected with the driving signal input end, and the second voltage end is connected with the conduction end; wherein when the driving signal input end inputs a high level, the switching unit is turned on; when the driving signal input end inputs a low level, the first voltage end provides a negative voltage to turn off the switching unit. The driving circuit of the embodiment of the application provides a negative voltage through the first voltage end, accelerates the discharging speed, thereby accelerating the turn-off of the switching unit and improving the response speed of the driving circuit.

Description

Technical Field

[0001] This application relates to the field of electronic system technology, and in particular to a drive circuit and a DC charging pile. Background Technology

[0002] DC charging pile power modules are used to convert AC power from the grid into DC power required by electric vehicle batteries. Within the power module, the driving performance of the drive circuit typically determines the module's efficiency, power density, reliability, and output power.

[0003] In related technologies, the discharge capability of the drive circuit to the gate capacitor is usually insufficient, resulting in a slow turn-off process of the MOSFET, which increases turn-off losses and delays the response speed of the drive circuit. Summary of the Invention

[0004] This application provides a driving circuit and a DC charging pile, which provides a negative voltage at a first voltage terminal to accelerate the discharge speed, thereby accelerating the turn-off of the switching unit and improving the response speed of the driving circuit.

[0005] The driving circuit of this application embodiment includes a switching unit, a driving signal input terminal, and an energy storage unit. The switching unit has a control terminal and a conduction terminal. The driving signal input terminal is connected to the control terminal and is used to input a driving signal. The energy storage unit includes a first voltage terminal and a second voltage terminal. The first voltage terminal is connected to the driving signal input terminal, and the second voltage terminal is connected to the conduction terminal. When the drive signal input terminal is high, the switch unit is turned on; when the drive signal input terminal is low, the first voltage terminal provides a negative voltage to turn the switch unit off.

[0006] In some embodiments, the energy storage unit includes an energy storage capacitor C1, with a first voltage terminal and a second voltage terminal formed at both ends of the energy storage capacitor C1.

[0007] In some embodiments, the energy storage unit further includes a Zener diode D1, the anode of which is connected to a first voltage terminal of the energy storage capacitor C1, and the cathode of which is connected to a second voltage terminal of the energy storage capacitor C1.

[0008] In some embodiments, the driving circuit further includes a resistor R1, one end of which is connected to the negative terminal of the Zener diode D1, and the other end of which is connected to the positive terminal of an external power supply. The positive terminal of the Zener diode D1 is connected to the negative terminal of the external power supply.

[0009] In some embodiments, the driving circuit further includes a bias circuit, which is connected between the driving signal input terminal and the control terminal, and the bias circuit includes a first current path and a second current path. When the drive signal input terminal is high, the first current path is turned on and the second current path is turned off; when the drive signal input terminal is low, both the first current path and the second current path are turned on.

[0010] In some embodiments, the first current path includes a resistor R2, with the two ends of the resistor R2 connected to the drive signal input terminal and the control terminal, respectively. The second current path includes a resistor R3 and a diode D2. One end of the resistor R3 is connected to the positive terminal of the diode D2, and the other end of the resistor R3 is connected between the resistor R2 and the control terminal. The negative terminal of the diode D2 is connected between the resistor R2 and the drive signal input terminal.

[0011] In some embodiments, the driving circuit further includes a bleed resistor R4, one end of which is connected between the resistor R2 and the driving signal input terminal, and the other end of which is connected between the second voltage terminal and the conduction terminal.

[0012] In some embodiments, the driving circuit further includes a protection circuit, which includes a resistor R5 and a capacitor C2. One end of the resistor R5 is connected to one end of the capacitor C2, and the other end of the resistor R5 is connected between the resistor R2 and the control terminal. The other end of the capacitor C2 is connected between the second voltage terminal and the conduction terminal.

[0013] In some embodiments, the driving circuit further includes a diode D3, the anode of which is connected to the first voltage terminal, and the cathode of which is connected to the driving signal input terminal.

[0014] The DC charging pile of this application embodiment includes the drive circuit of any of the above embodiments.

[0015] In this embodiment of the driving circuit, when the driving signal input terminal is high-level, the switching unit is charged, causing it to turn on. When the driving signal input terminal is low-level, the switching unit is discharged, turning it off. Simultaneously, a negative voltage is provided at the first voltage terminal, which can be synchronously applied to the driving signal input terminal. This allows the switching unit to discharge under a larger voltage difference, accelerating the discharge speed and thus speeding up the turn-off speed, reducing turn-off losses, and improving the response speed of the driving circuit. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the driving circuit in an embodiment of this application.

[0018] Figure 2 This is a circuit example diagram of a driving circuit according to an embodiment of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] In the description of this application, it should be understood that terms such as “first” and “second” are used only to distinguish similar objects and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0021] This application provides a drive circuit, which can generally be applied to switching power supplies such as server power supplies and communication base station power supplies, as well as in power generation and storage devices such as photovoltaic inverters, wind power converters, and energy storage converters, and in mechanical devices such as frequency converters, servo drives, and industrial robots. In this embodiment, the drive circuit is used in the power module of a DC charging pile.

[0022] In practical applications, the turn-off process of MOSFET Q1 is slow, resulting in a slow response speed of the entire drive circuit. The drive circuit of this application embodiment can accelerate the turn-off of MOSFET Q1 and improve the response speed of the drive circuit.

[0023] refer to Figure 1 The driving circuit includes a switching unit, a driving signal input terminal 11, and an energy storage unit.

[0024] The switching unit has a control terminal 10 and a conduction terminal 20. For practical applications, please refer to... Figure 2The switching unit can be a MOSFET Q1. The control terminal 10 forms the gate (G) of the MOSFET Q1, and the conduction terminal 20 forms the source (S) of the MOSFET Q1. The MOSFET Q1 also has a drain (D) for connecting an external load. A parasitic capacitance exists between the gate (G) and the source (S). The driving circuit charges and discharges this parasitic capacitance. During charging, the MOSFET Q1 is turned on; during discharging, the MOSFET Q1 is turned off. In this embodiment, the MOSFET Q1 is specifically a silicon carbide MOSFET Q1.

[0025] Continue to refer to Figure 1 The drive signal input terminal 11 is connected to the control terminal 10 and is used to input drive signals.

[0026] The energy storage unit includes a first voltage terminal 30 and a second voltage terminal 40. The first voltage terminal 30 is connected to the drive signal input terminal 11, and the second voltage terminal 40 is connected to the conduction terminal 20.

[0027] Specifically, when the drive signal input terminal 11 is high, the drive switch unit is turned on; when the drive signal input terminal 11 is low, the first voltage terminal 30 provides a negative voltage to drive the switch unit to turn off.

[0028] In this embodiment of the driving circuit, when the driving signal input terminal 11 is high, the gate G of the MOSFET Q1 is charged to turn on the MOSFET Q1. When the driving signal input terminal 11 is low, the gate G of the MOSFET Q1 is discharged to turn off the MOSFET Q1. During the discharge of the gate G of the MOSFET Q1, the first voltage terminal 30 provides a negative voltage, which can be synchronously applied to the driving signal input terminal 11. This allows the gate G of the MOSFET Q1 to discharge under a larger voltage difference, accelerating the discharge speed, speeding up the turn-off speed of the MOSFET Q1, reducing turn-off losses, and improving the response speed of the driving circuit.

[0029] In some embodiments, continue to refer to Figure 2 The energy storage unit includes an energy storage capacitor C1. A first voltage terminal 30 and a second voltage terminal 40 are formed across the two ends of the energy storage capacitor C1, for example, at the two plates of the energy storage capacitor C1. In practical applications, the energy storage unit also includes a Zener diode D1. The positive terminal of the Zener diode D1 is connected to the first voltage terminal 30 of the energy storage capacitor C1, and the negative terminal of the Zener diode D1 is connected to the second voltage terminal 40 of the energy storage capacitor C1.

[0030] The energy storage capacitor C1 stores electrical energy and provides a low voltage when the MOSFET Q1 is turned off, thus facilitating the turn-off of Q1. The Zener diode D1 regulates its reverse current when the input voltage of the drive circuit changes significantly or for a long period, thereby stabilizing the voltage across the energy storage capacitor C1 and achieving a voltage regulation effect.

[0031] In some embodiments, continue to refer to Figure 2 The driving circuit also includes a resistor R1. One end of resistor R1 is connected to the cathode of Zener diode D1, and the other end of resistor R1 is connected to the positive terminal of the external power supply. The anode of Zener diode D1 is connected to the negative terminal of the external power supply. The voltage between the positive and negative terminals of the external power supply is +18V.

[0032] In this embodiment, the external power supply may include a power module and a transformer. The transformer is connected to the power module and has a first pin and a second pin. The first pin constitutes the positive terminal of the external power supply, and the second pin constitutes the negative terminal. The transformer transforms the voltage from the power module and applies it to a resistor R1 and a Zener diode D1. The resistor R1 limits the current to prevent excessive current from damaging the Zener diode D1. Additionally, the resistor R1 and the Zener diode D1 also achieve a voltage divider effect.

[0033] In one example, continue to refer to Figure 2 The driving circuit may also include a capacitor C3, with one end of capacitor C3 connected to one end of resistor R1 and the other end of capacitor C3 connected to the other end of resistor R1. Capacitor C3 and resistor R1 can form an RC filter to smooth the signal, remove noise, and achieve filtering of the external power supply.

[0034] In some embodiments, continue to refer to Figure 1 The driving circuit also includes a bias circuit, which is connected between the driving signal input terminal 11 and the control terminal 10. The bias circuit includes a first current path and a second current path.

[0035] When the drive signal input terminal 11 is high, the first current path is turned on and the second current path is turned off; when the drive signal input terminal 11 is low, both the first and second current paths are turned on.

[0036] In practical applications, continue to refer to Figure 2 The first current path includes resistor R2, with its two ends connected to the drive signal input terminal 11 and the control terminal 10, respectively. The second current path includes resistor R3 and diode D2, with one end of resistor R3 connected to the anode of diode D2, the other end of resistor R3 connected between resistor R2 and control terminal 10, and the cathode of diode D2 connected between resistor R2 and drive signal input terminal 11.

[0037] When the drive signal input terminal 11 is high, due to the unidirectional conductivity of diode D2, the current flows only through resistor R2 into the gate G of MOSFET Q1, charging the gate G of MOSFET Q1. When the drive signal input terminal 11 is low, the gate G of MOSFET Q1 discharges outward, i.e., outputs current. Under the unidirectional conductivity of diode D2, this current flows through resistor R2, resistor R3, and diode D2, i.e., simultaneously through the first current path and the second current path. Thus, the gate G of MOSFET Q1 discharges through a dual path, accelerating the discharge speed and further speeding up the turn-off of MOSFET Q1, making the response speed of the drive circuit faster.

[0038] In some embodiments, continue to refer to Figure 2 The driving circuit also includes a bleed resistor R4. One end of the bleed resistor R4 is connected between the resistor R2 and the driving signal input terminal 11, and the other end of the bleed resistor R4 is connected between the second voltage terminal 40 and the conduction terminal 20.

[0039] When the drive signal input terminal 11 stops inputting the drive signal, the gate G of MOSFET Q1 may continue to accumulate charge due to device leakage. The bleed resistor R4 forms a bleed path from the gate G to the source S of MOSFET Q1. The charge accumulated at the gate G can pass through this bleed path to the source S, preventing the gate voltage from continuously rising and causing a false turn-on phenomenon, thereby preventing the device from burning out.

[0040] In some embodiments, continue to refer to Figure 2 The driving circuit also includes a protection circuit, which includes a resistor R5 and a capacitor C2. One end of the resistor is connected to one end of the capacitor C2, the other end of the resistor R5 is connected between the resistor R2 and the control terminal 10, and the other end of the capacitor C2 is connected between the second voltage terminal 40 and the conduction terminal 20.

[0041] In some embodiments, continue to refer to Figure 2 The driving circuit also includes diode D3, with the anode of diode D3 connected to the first voltage terminal 30 and the cathode of diode D3 connected to the driving signal input terminal 11. The first voltage terminal 30 is connected to the driving signal input terminal 11 through diode D3.

[0042] refer to Figure 2 In this embodiment of the application, the driving circuit further includes a single-channel isolated gate driver U1, which has an input side and an output side isolated by an insulating material.

[0043] The input side has an anode (ANODE), a first power supply terminal (VCC1), and a cathode (CATHODE). The anode (ANODE) ​​is connected to the PWM output pin of the MCU (controller) through a current-limiting resistor (R6) to receive drive signals. The first power supply terminal (VCC1) is connected to the same supply voltage of the MCU, for example, +3.3V. The cathode (CATHODE) is grounded through a current-limiting resistor (R7).

[0044] The output side has a second power supply terminal VCC2, an output terminal VOUT, and a reference terminal VEE. The second power supply terminal VCC2 is connected to the positive terminal of the external power supply, the reference terminal VEE is connected to the negative terminal of the external power supply, and the output terminal VOUT is connected to the drive signal input terminal 11.

[0045] The MCU's drive signal is sent from the anode ANODE, through the gate driver U1, to the output VOUT, and finally to the control terminal 10 through the drive signal input terminal 11, thereby realizing the charging and discharging control of the gate G of the MOS transistor Q1.

[0046] In one example, continue to refer to Figure 2 A decoupling capacitor C4 is connected between the second power supply terminal VCC2 and the reference terminal VEE.

[0047] This application also provides a DC charging pile, including the drive circuit in any of the above embodiments.

[0048] The technical advantages of the DC charging pile in this embodiment are the same as those of the drive circuit in the above embodiments, and will not be repeated here.

[0049] It should be noted that in the embodiments of this application, "connection" can be understood as electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0050] It should be noted that, in the embodiments of this application, "electrical connection" can be a direct connection between two electrical components or an indirect connection. For example, the electrical connection between A and B can be achieved by A and B being directly connected, or by A and B being indirectly connected through one or more other electrical components.

[0051] The driving circuit and DC charging pile provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A driving circuit, characterized in that, include: The switching unit has a control terminal and a conduction terminal; The drive signal input terminal is connected to the control terminal and is used to input drive signals; An energy storage unit includes a first voltage terminal and a second voltage terminal, wherein the first voltage terminal is connected to the drive signal input terminal and the second voltage terminal is connected to the conduction terminal; When the drive signal input terminal is high, the switch unit is turned on; when the drive signal input terminal is low, the first voltage terminal provides a negative voltage to turn the switch unit off.

2. The driving circuit according to claim 1, characterized in that, The energy storage unit includes an energy storage capacitor C1, with the first voltage terminal and the second voltage terminal formed at both ends of the energy storage capacitor C1.

3. The driving circuit according to claim 2, characterized in that, The energy storage unit also includes a Zener diode D1, the positive terminal of which is connected to the first voltage terminal of the energy storage capacitor C1, and the negative terminal of which is connected to the second voltage terminal of the energy storage capacitor C1.

4. The driving circuit according to claim 3, characterized in that, It also includes a resistor R1, one end of which is connected to the negative terminal of the Zener diode D1, and the other end of which is connected to the positive terminal of an external power supply. The positive terminal of the Zener diode D1 is connected to the negative terminal of the external power supply.

5. The driving circuit according to claim 1, characterized in that, It also includes a bias circuit, which is connected between the drive signal input terminal and the control terminal, and the bias circuit includes a first current path and a second current path; When the drive signal input terminal is high, the first current path is turned on and the second current path is turned off; when the drive signal input terminal is low, both the first current path and the second current path are turned on.

6. The driving circuit according to claim 5, characterized in that, The first current path includes a resistor R2, with its two ends connected to the drive signal input terminal and the control terminal, respectively. The second current path includes a resistor R3 and a diode D2. One end of the resistor R3 is connected to the positive terminal of the diode D2, and the other end of the resistor R3 is connected between the resistor R2 and the control terminal. The negative terminal of the diode D2 is connected between the resistor R2 and the drive signal input terminal.

7. The driving circuit according to claim 6, characterized in that, The driving circuit further includes a bleed resistor R4, one end of which is connected between the resistor R2 and the driving signal input terminal, and the other end of which is connected between the second voltage terminal and the conducting terminal.

8. The driving circuit according to claim 6, characterized in that, The driving circuit also includes a protection circuit, which includes a resistor R5 and a capacitor C2. One end of the resistor R5 is connected to one end of the capacitor C2, and the other end of the resistor R5 is connected between the resistor R2 and the control terminal. The other end of the capacitor C2 is connected between the second voltage terminal and the conduction terminal.

9. The driving circuit according to claim 1, characterized in that, The driving circuit also includes a diode D3, the positive terminal of which is connected to the first voltage terminal, and the negative terminal of which is connected to the driving signal input terminal.

10. A DC charging pile, characterized in that, Includes the driving circuit described in any one of claims 1-9.

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