A drive circuit for a power semiconductor device

Abstract

The embodiment of the application discloses a driving circuit of a power semiconductor device, which comprises a resonance circuit, wherein the resonance circuit comprises a resonance resistance, a resonance inductance and a resonance capacitance; the resonance resistance and the resonance inductance are connected in series to form a series circuit; one end of the series circuit is connected to an output end of an isolation device of the driving circuit; the other end of the series circuit is connected to an input end of an amplification circuit of the driving circuit and one end of the resonance capacitance respectively; and the other end of the resonance capacitance is connected to a reference ground of a power supply of the driving circuit; wherein the resonance circuit is in an underdamped state and is used for outputting a reference voltage of the amplification circuit; and wherein the reference voltage is a voltage with a preset change rate.

Description

Technical Field

[0001] The present application relates to the technical field of drive circuits for power semiconductor devices, and in particular to a drive circuit for a power semiconductor device. Background Art

[0002] Currently, wide-bandgap semiconductor devices, such as silicon carbide metal-oxide-semiconductor field-effect transistors (MOSFETs), are used in an increasing number of power electronic devices. However, how to safely and reliably drive silicon carbide MOSFETs has become the key to the reliability of power electronic devices. Currently, the driving circuit of silicon carbide MOSFETs is similar to that of insulated gate bipolar transistors (IGBTs), mainly including isolation, current amplification, overcurrent protection, etc. The main difference is that the driving voltage is slightly different.

[0003] In related technologies, parasitic inductance and gate capacitance exist in the gate drive loop of the silicon carbide MOSFET drive circuit. Coupled with the Miller effect, the gate voltage waveform oscillates. This oscillation may cause increased switching losses of the silicon carbide MOSFET, false turn-on or false turn-off, and affect the operating stability of the power semiconductor device.

[0004] Application Contents

[0005] The embodiments of the present application are intended to provide a driving circuit for a power semiconductor device to improve the operating stability of the power semiconductor device in the related art.

[0006] The technical solution of this application is achieved as follows:

[0007] A drive circuit for a power semiconductor device, the drive circuit comprising: a resonant circuit, the resonant circuit comprising: a resonant resistor, a resonant inductor, and a resonant capacitor, the resonant resistor and the resonant inductor being connected in series to form a series circuit, one end of the series circuit being connected to the output end of an isolation device of the drive circuit, the other end of the series circuit being respectively connected to the input end of an amplifier circuit of the drive circuit and one end of the resonant capacitor, the other end of the resonant capacitor being connected to a reference ground of a power supply of the drive circuit; wherein:

[0008] The resonant circuit is in an underdamped state and is used to output a reference voltage of the amplifier circuit; wherein the reference voltage is a voltage with a preset change rate.

[0009] The driving circuit of the power semiconductor device provided in the embodiment of the present application includes: a resonant circuit, the resonant circuit includes: a resonant resistor, a resonant inductor and a resonant capacitor, the resonant resistor and the resonant inductor are connected in series to obtain a series circuit, one end of the series circuit is connected to the output end of the isolation device of the driving circuit, the other end of the series circuit is respectively connected to the input end of the amplifier circuit of the driving circuit and one end of the resonant capacitor, and the other end of the resonant capacitor is connected to the reference ground of the power supply of the driving circuit; wherein the resonant circuit is in an underdamped state and is used to output a reference voltage of the amplifier circuit; wherein the reference voltage is a voltage with a preset change rate; that is, in the embodiment of the present application, by A resonant circuit is added between the output end and the input end of the amplifier circuit, and the resonant circuit operates in an underdamped state, so that the output voltage of the resonant circuit is a voltage with a controllable change rate. Then, the output voltage of the resonant circuit, that is, the reference voltage of the amplifier circuit is controlled to a voltage with a preset change rate, so that the resonant circuit provides a reference voltage with a controllable change rate to the amplifier circuit. The reference voltage with a controllable change rate passes through the amplifier circuit so that the gate voltage of the power semiconductor device also becomes a gate voltage with a controllable change rate, thereby eliminating the oscillation of the gate voltage, avoiding the switching loss of the power semiconductor device, and avoiding erroneous turn-on or turn-off, thereby improving the working stability of the power semiconductor device. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A schematic structural diagram of an optional driving circuit for a power semiconductor device provided in an embodiment of the present application;

[0011] Figure 2 A schematic structural diagram of another optional driving circuit for a power semiconductor device provided in an embodiment of the present application;

[0012] Figure 3 A schematic structural diagram of another optional driving circuit for a power semiconductor device provided in an embodiment of the present application;

[0013] Figure 4 A schematic structural diagram of another optional driving circuit for a power semiconductor device provided in an embodiment of the present application;

[0014] Figure 5 A schematic structural diagram of an example of an optional driving circuit for a power semiconductor device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0015] In order to better understand the purpose, structure and function of the present application, the control method and control system of a motor of the present application are further described in detail below with reference to the accompanying drawings.

[0016] The embodiment of the present application provides a driving circuit for a power semiconductor device. Figure 1A schematic diagram of a drive circuit for a power semiconductor device according to an embodiment of the present invention is provided. Figure 1 As shown, the driving circuit may include:

[0017] The resonant circuit 100 includes a resonant resistor 11, a resonant inductor 12, and a resonant capacitor 13. The resonant resistor 11 and the resonant inductor 12 are connected in series to form a series circuit. One end of the series circuit is connected to the output end of the isolation device of the driving circuit. The other end of the series circuit is respectively connected to the input end of the amplifier circuit of the driving circuit and one end of the resonant capacitor 13. The other end of the resonant capacitor 13 is connected to the reference ground of the power supply of the driving circuit.

[0018] The resonant circuit 100 is in an underdamped state and is used to output a reference voltage of the amplifier circuit; wherein the reference voltage is a voltage with a preset change rate.

[0019] At present, in the relevant technology, the driving circuit of the power semiconductor device has the problem of gate voltage oscillation, which leads to increased switching loss of the power semiconductor device, false turn-on or false turn-off, and affects the working stability of the power semiconductor device. In order to improve the working stability of the power semiconductor device, the embodiment of the present application provides an RLC circuit, namely the above-mentioned resonant circuit 100, and the resonant circuit 100 is arranged between the isolation device and the amplifier circuit, so that the output of the resonant circuit 100 is the input voltage of the amplifier circuit, that is, the reference voltage. By operating the resonant circuit 100 in an underdamped state, the resonant circuit 100 outputs a reference voltage with a preset change rate.

[0020] By adding the above-mentioned resonant circuit 100, the reference voltage of the amplifier circuit can be adjusted according to the needs of each component of the resonant circuit 100 to obtain a reference voltage with a controllable change rate, thereby eliminating the oscillation of the gate voltage by controlling the reference voltage of the amplifier circuit, thereby improving the operating stability of the power semiconductor device.

[0021] It should be noted that the above-mentioned power semiconductor device can be a MOSFET, a silicon carbide MOSFET, or an IGBT. Here, the embodiments of the present application do not make specific limitations on this.

[0022] Among them, the above-mentioned isolation device can be an optical isolation device, a capacitive isolation device, or a magnetic field isolation device. Here, the embodiments of the present application do not make specific limitations on this.

[0023] In addition, in order to prevent the gate voltage of power semiconductor devices from being too high and causing loss to power semiconductor devices, Figure 2 A schematic structural diagram of another optional semiconductor power device driving circuit provided in an embodiment of the present application is shown in FIG. Figure 2As shown, in an optional embodiment, the resonant circuit 100 further includes: a voltage stabilizing circuit 21; one end of the voltage stabilizing circuit 21 is connected to the input end of the amplifier circuit, and the other end of the voltage stabilizing circuit 21 is connected to the reference ground; wherein,

[0024] The voltage stabilizing circuit 21 is used to clamp the reference voltage so that the reference voltage falls within a preset voltage range.

[0025] Here, a voltage stabilizing circuit 21 is provided between the input end of the amplifier circuit and the reference ground, so that the reference voltage before the amplifier is clamped within a preset voltage range. In this way, by clamping the reference voltage of the amplifier circuit, it is possible to prevent excessive power consumption caused by excessive gate voltage of the power semiconductor device and the risk of damage to the power semiconductor device due to spike voltage.

[0026] In order to achieve the clamping of the reference voltage, in an optional embodiment, the voltage stabilizing circuit 21 includes: a first voltage stabilizing tube and a second voltage stabilizing tube; wherein,

[0027] The anode of the first voltage-stabilizing tube is connected to the anode of the second voltage-stabilizing tube, the cathode of the first voltage-stabilizing tube is connected to the input end of the amplifier circuit, and the cathode of the second voltage-stabilizing tube is connected to the reference ground.

[0028] It can be understood that a voltage stabilizing circuit is formed by connecting two voltage stabilizing tubes in series. For example, the anodes of the two voltage stabilizing tubes are connected, and the cathodes of the two voltage stabilizing tubes are respectively connected to the input end of the amplifier circuit and the reference ground. In this way, the two voltage stabilizing tubes can clamp the reference voltage.

[0029] In practical applications, the reference voltage is usually clamped at (1.05-1.1) times the power supply voltage, which may be the first power supply voltage or the second power supply voltage.

[0030] In order to make the reference voltage a reference voltage with a preset change rate, the values ​​of the resonant resistor 11, the resonant capacitor 13 and the resonant inductor 12 can be set as needed. In an optional embodiment, the capacitance value of the resonant capacitor 13 is positively correlated with the ratio of the gate capacitance of the power semiconductor device to the amplification factor of the transistor in the amplifier circuit.

[0031] That is to say, from the structure of the driving circuit provided in the embodiment of the present application, it can be seen that the angular frequency of the resonant circuit 100 is proportional to the rate of change of the reference voltage. Therefore, the rate of change of the reference voltage can be controlled by controlling the angular frequency of the resonant circuit 100. Specifically, the size of the angular frequency of the resonant circuit 100 can be determined by setting the values ​​of the resonant capacitor 13, the resonant inductor 12 and the resonant resistor 11.

[0032] Among them, for the structure of the above-mentioned resonant circuit 100, the capacitance value of the resonant capacitor 13 is mainly related to the gate capacitance of the power semiconductor device and the amplification factor of the amplifier circuit transistor. Specifically, the capacitance value of the resonant capacitor 13 is positively correlated with the ratio of the gate capacitance to the amplification factor of the transistor. It can be seen that the larger the ratio of the gate capacitance of the power semiconductor device to the amplification factor of the transistor is, the larger the capacitance value of the resonant capacitor 13 is, and the smaller the gate capacitance of the power semiconductor device and the amplification factor of the transistor is, the smaller the capacitance value of the resonant capacitor 13 is.

[0033] Regarding the inductance of the resonant inductor 12 , in an optional embodiment, the inductance of the resonant inductor 12 is inversely correlated with the product of the square of the angular frequency of the resonant circuit 100 and the capacitance of the resonant capacitor 13 .

[0034] The inductance of the above-mentioned resonant circuit 100 is mainly related to the square of the angular frequency of the resonant circuit 100 and the capacitance of the resonant capacitor 13. Specifically, the inductance of the resonant circuit 100 is positively correlated with the product of the square of the angular frequency of the resonant circuit 100 and the capacitance of the resonant capacitor 13. It can be seen that when the product of the square of the angular frequency of the resonant circuit 100 and the capacitance of the resonant capacitor 13 is larger, the inductance of the resonant circuit 100 is smaller, and when the product of the square of the angular frequency of the resonant circuit 100 and the capacitance of the resonant capacitor 13 is smaller, the inductance of the resonant circuit 100 is smaller.

[0035] Regarding the resistance value of the resonant resistor 11 , in an optional embodiment, the resistance value of the resonant resistor 11 is positively correlated with the product of the square root of the ratio of the inductance value of the resonant inductor 12 to the capacitance value of the resonant capacitor 13 and the damping ratio of the resonant circuit 100 .

[0036] According to the structure of the resonant circuit 100, it can be obtained that the resistance value of the resonant resistor 11 is related to the damping ratio of the resonant circuit 100, and is also related to the capacitance value of the resonant capacitor 13 and the inductance value of the resonant inductor 12. The square root of the ratio between the inductance value of the resonant inductor 12 and the capacitance value of the resonant capacitor 13 is calculated, and the resistance value of the resonant resistor 11 is proportional to the product of the square root of the ratio and the damping ratio. It can be seen that the greater the product of the square root of the ratio between the inductance value of the resonant inductor 12 and the capacitance value of the resonant capacitor 13 and the damping ratio, the greater the resistance value of the resonant resistor 11, and the smaller the product of the square root of the ratio between the inductance value of the resonant inductor 12 and the capacitance value of the resonant capacitor 13 and the damping ratio, the smaller the resistance value of the resonant resistor 11.

[0037] In addition, when the resonant circuit 100 is in an underdamped state, in order to control the reference voltage to a voltage with a preset change rate, in an optional embodiment, the damping ratio of the resonant circuit 100 is greater than or equal to 0.2 and less than or equal to 0.5.

[0038] That is, when the damping ratio of the resonant circuit 100 is between 0.2 and 0.5, the reference voltage can be controlled to a voltage with a preset change rate, which can eliminate the existing oscillation of the gate voltage, thereby improving the operating stability of the power semiconductor device.

[0039] In addition, in addition to the oscillation of gate voltage, power semiconductor devices also experience excessive spike voltages and damage during shutdown due to the presence of parasitic inductance in the commutation circuit. To prevent power semiconductor devices from being subjected to excessive spike voltages, Figure 3 A schematic structural diagram of another optional driving circuit of a power semiconductor device provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, in an optional embodiment, the drive circuit further includes: a feedforward circuit 300, the feedforward circuit 300 includes: a transient voltage suppressor diode 31, a feedforward capacitor 32, a first feedforward resistor 33, a second feedforward resistor 34, a first diode 35 and a second diode 36; wherein, the cathode of the transient voltage suppressor diode 31 is connected to the drain or collector of the power semiconductor device, the anode of the transient voltage suppressor diode 31 is connected to one end of the feedforward capacitor 32, one end of the feedforward capacitor 32 is respectively connected to one end of the first feedforward resistor 33 and the anode of the first diode 35, the cathode of the first diode 35 is connected to one end of the second feedforward resistor 34, the other end of the second feedforward resistor 34 is connected to the gate of the power semiconductor device, the other end of the first feedforward resistor 33 is connected to the cathode of the second diode 36, and the anode of the second diode 36 is connected to the second power supply of the power supply; wherein,

[0040] The feedforward circuit 300 is used to charge the gate capacitor to reduce the rate of decrease of the gate voltage when the power semiconductor device is turned off;

[0041] The feedforward circuit 300 is further configured to discharge the feedforward capacitor 32 when the power semiconductor device is turned on.

[0042] That is to say, in addition to the above-mentioned resonant circuit 100, the above-mentioned driving circuit also includes a feedforward circuit 300. The feedforward circuit 300 has a total of three ports, one port is the cathode of the transient voltage suppression diode 31, connected to the drain or collector of the power semiconductor device, another port is one end of the second feedforward resistor 34, connected to the gate of the power semiconductor device, and another port is the anode of the second diode 36, connected to the second power supply, thus serving as the feedforward circuit 300.

[0043] Here, it should be noted that the anode of the second diode 36 can be connected to the positive electrode of the second power supply, or can be connected to the negative electrode of the second power supply, and this embodiment of the present application does not specifically limit this.

[0044] Among them, taking the power semiconductor device as silicon carbide MOSFET as an example, when the power semiconductor device is turned off, after the drain-source voltage of the power semiconductor device exceeds the breakdown voltage of the transient voltage suppression diode 31, current will flow through the feed-forward capacitor 32 and charge the gate capacitor through the first diode 35 and the second feed-forward resistor 34, thereby slowing down the gate voltage drop speed, thereby suppressing the drain-source voltage of the silicon carbide MOSFET from peaking and damaging the silicon carbide MOSFET.

[0045] In addition, when the silicon carbide MOSFET is turned on, the feed-forward capacitor 32 is discharged through the transient voltage suppression diode 31, the silicon carbide MSOFET, the second power supply, the second diode 36 and the first feed-forward resistor 33, so that the current on the feed-forward capacitor is larger when the power semiconductor device is turned off, which can increase the charging speed of the gate capacitance of the power semiconductor device when it is turned off, thereby effectively achieving the suppression of the drain-source voltage when the power semiconductor device is turned off next time.

[0046] When the power semiconductor device is a MOSFET or a silicon carbide MOSFET, the cathode of the transient voltage suppression diode 31 is connected to the drain of the MOSFET or the silicon carbide MOSFET; when the power semiconductor device is an IGBT, the cathode of the transient voltage suppression diode 31 is connected to the collector of the IGBT.

[0047] The feedforward circuit 300 mainly reduces the falling speed of the gate voltage by charging the feedforward capacitor 32 when the power semiconductor device is turned off. Based on this, in order to further slow down the falling speed of the gate voltage, Figure 4 A schematic structural diagram of another optional driving circuit of a power semiconductor device provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, in an optional embodiment, the feedforward circuit 300 further includes: a transistor 41, a third diode 42, a third feedforward resistor 43 and a fourth feedforward resistor 44; wherein,

[0048] The third feed-forward resistor 43 is arranged between the first feed-forward resistor 33 and the second diode 36. The base of the transistor 41 is connected to the connection point of the first feed-forward resistor 33 and the third feed-forward resistor 43. The collector of the transistor 41 is connected to the positive electrode of the first power supply. The emitter of the transistor 41 is connected to the cathode of the second diode 36. One end of the fourth feed-forward resistor 44 is connected to the anode of the third diode 42. The other end of the fourth feed-forward resistor 44 is connected to the emitter of the transistor 41. The cathode of the third diode 42 is connected to one end of the resonant capacitor 13.

[0049] The feedforward circuit 300 is used to charge the resonant capacitor 13 after the current amplified by the transistor 41 flows through the fourth feedforward resistor 44 and the third diode 42 when the power semiconductor device is turned off, so as to reduce the falling rate of the reference voltage.

[0050] It can be understood that a transistor 41 is added to the feedforward circuit 300. The transistor 41 is used to amplify the base current when the power semiconductor device is turned off. The amplified current flows through the fourth feedforward resistor 44 and the third diode 42 and then flows to the resonant capacitor 13, thereby charging the resonant capacitor 13, slowing down the falling speed of the reference voltage, and further slowing down the falling speed of the gate voltage, thereby preventing the power semiconductor device from being damaged by excessive peak voltage.

[0051] Finally, in order to enable the transistor to amplify the base current, in an optional embodiment, the feedforward circuit further includes: a fourth diode; wherein,

[0052] The anode of the fourth diode is connected to the base of the transistor, and the cathode of the fourth diode is connected to the collector of the transistor;

[0053] The fourth diode is used to clamp the base voltage of the transistor to the power supply voltage of the first power supply.

[0054] That is to say, by adding a fourth diode in the feedforward circuit 300, specifically, adding the fourth diode between the base and the collector of the transistor 41, the fourth diode is used to clamp the base voltage of the transistor 41 to the voltage of the first power supply, so that the transistor 41 can be turned on and the current flowing through the base can be amplified, thereby charging the resonant capacitor.

[0055] The following examples are used to illustrate the driving circuit of the power semiconductor device described in one or more of the above embodiments.

[0056] Figure 5 A schematic diagram of an example of a drive circuit for a power semiconductor device provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, the power semiconductor device is a silicon carbide MOSFET, represented by M1, the first power supply is V1, the second power supply is V2, the gate of M1 is connected to the output end of the amplifier circuit, and the amplifier circuit is a push-pull amplifier circuit composed of a transistor Q1, a transistor Q2, an on-resistor R3 and an off-resistor R4. The negative electrodes of V1 and V2 are both connected to the reference ground of the power supply, wherein V1 and V2 are power supplies for the drive circuit, the source of M1 is connected to the reference ground, and the drain of M1 is connected to the U-phase lower bridge in the three-phase inverter circuit.

[0057] In addition, in order to improve the working stability of M1, Figure 5In the embodiment, the driving circuit further includes: an RLC resonant stage circuit (equivalent to the above resonant circuit) and a dv / dt feedforward control stage circuit (equivalent to the above feedforward circuit).

[0058] Among them, Vin is the input voltage of the resonant circuit and the control voltage signal output by the optocoupler, ranging from -5V to +15V; the reference voltage Vref is the output voltage of the RLC resonant circuit composed of R1, L1 and C1, ZD1 and ZD2 are Zener diodes; Q1 and Q2 form the amplifier stage circuit, R3 and R4 are the turn-on resistor and turn-off resistor of the gate drive, respectively; transient suppression diode TVS2 is used for gate protection; transient suppression diode TVS1, C2, D2, R5, R6, R7, Q3, D4, R2, and D1 constitute the dv / dt feedforward control stage circuit.

[0059] For the RLC resonant stage circuit, the working principle is as follows:

[0060] The RLC resonant circuit operates in an underdamped state, with a damping ratio δ between 0.2 and 0.5. The overshoot voltage of Vref is approximately 20% to 50%. ZD1 and ZD2 clamp Vref at (1.05 to 1.1) times the V1 or V2 supply voltage. The rising and falling slopes of Vref can be determined based on the switching speed and loss of M1. The angular frequency of the RLC resonant circuit is:

[0061]

[0062] Among them, ω N represents the angular frequency, and δ represents the damping ratio.

[0063] If Ciss is the gate capacitance of M1 and β is the gain of Q1 and Q2, then

[0064] C1=(5~10)·Ciss / β (2)

[0065]

[0066]

[0067] For the amplifier stage circuit (equivalent to the above amplifier circuit), the working principle is as follows:

[0068] The amplifier circuit is composed of Q1, Q2, R3 and R4, among which R3 is the gate drive turn-on resistor, which is used to control the turn-on time of M1; R4 is the gate drive turn-off resistor, which is used to control the turn-off time of M1; the input of the amplifier circuit is the reference voltage Vref, and Vg is the output voltage of the amplifier circuit, that is, the gate voltage of M1. Figure 5 The structure of the circuit is known.

[0069] Vg=Vref+Vbe (5)

[0070] Wherein, Vbe is the base voltage of Q1 or Q2; Q1 and Q2 form a push-pull amplifier circuit for amplifying the output current of the RLC resonant stage and driving M1.

[0071] For the dv / dt feedforward control stage circuit, the working principle is as follows:

[0072] If the parasitic inductance of the commutation circuit of M1 is Ls, the drain-source current is Id, the drain-source voltage is Vds, the transconductance of M1 is gm, and the gate turn-on voltage is Vth, then it can be seen from the following formula (6) that when the parasitic inductance is constant, the drain-source voltage peak Vds is proportional to the rate of decrease of the gate voltage Vg.

[0073]

[0074] The dv / dt feedforward control stage circuit consists of transient suppressor diode TVS1, C2, D2, R5, R6, R7, Q3, D4, R2, and D1. When M1 is turned off, its drain-source voltage exceeds the breakdown voltage of TVS1, causing current to flow through C2. Part of this current charges M1's gate capacitance through D2 and R5, slowing the rate of Vg's decline. The other part provides base current for Q3 through R6. After being amplified by Q3, this current charges C1 through R2 and D1, slowing the rate of Vref's decline. After passing through the amplification stage, Vref further slows the rate of Vg's decline, thereby suppressing the drain-source voltage spike and preventing M1 from overvoltage.

[0075] Among them, D4 is used to clamp the base potential of Q3 to the power supply V1. When M1 is turned on, C2 is discharged through TVS1, M1, V2, D3, R7 and R6, so that dv / dt feedback can be performed at the next shutdown. According to Kirchhoff's voltage law, the following equation holds:

[0076]

[0077] Where Re is the equivalent resistance from the feedback current flowing through C2 to the power ground. Therefore, the feedback current can be obtained as follows:

[0078]

[0079] In summary, the RLC resonant circuit in the front stage can generate a reference voltage waveform with controllable slope, eliminating oscillation and delay. The drain dv / dt voltage feed-forward circuit in the back stage can quickly adjust the gate voltage according to the drain voltage spike, thereby reducing the turn-off speed of the silicon carbide MOSFET, ensuring that the turn-off voltage spike is within a reasonable range, and effectively preventing device overvoltage.

[0080] The driving circuit of the power semiconductor device provided in the embodiment of the present application includes: a resonant circuit, the resonant circuit includes: a resonant resistor, a resonant inductor and a resonant capacitor, the resonant resistor and the resonant inductor are connected in series to obtain a first series circuit, one end of the first series circuit is connected to the output end of the isolation device of the driving circuit, the other end of the first series circuit is respectively connected to the input end of the amplifier circuit of the driving circuit and one end of the resonant capacitor, and the other end of the resonant capacitor is connected to the reference ground of the power supply of the driving circuit; wherein the resonant circuit is in an underdamped state and is used to output a reference voltage of the amplifier circuit; wherein the reference voltage is a voltage with a preset change rate; that is, in the embodiment of the present application, by the isolator in the driving circuit A resonant circuit is added between the output end of the device and the input end of the amplifier circuit, and the resonant circuit operates in an underdamped state. In this way, the output voltage of the resonant circuit is a voltage with a controllable change rate. Then, the output voltage of the resonant circuit, that is, the reference voltage of the amplifier circuit is controlled to a voltage with a preset change rate, so that the resonant circuit provides the amplifier circuit with a reference voltage with a controllable change rate. The reference voltage with a controllable change rate passes through the amplifier circuit so that the gate voltage of the power semiconductor device also becomes a gate voltage with a controllable change rate, thereby eliminating the oscillation of the gate voltage, avoiding the switching loss of the power semiconductor device, and avoiding erroneous turn-on or turn-off, thereby improving the working stability of the power semiconductor device.

[0081] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Furthermore, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) containing computer-usable program code.

[0082] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0083] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0084] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0085] The above description is merely a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application.

Claims

1. A driving circuit for a power semiconductor device, characterized in that: The driving circuit includes: a resonant circuit, the resonant circuit includes: a resonant resistor, a resonant inductor and a resonant capacitor, the resonant resistor and the resonant inductor are connected in series to form a series circuit, one end of the series circuit is connected to the output end of the isolation device of the driving circuit, the other end of the series circuit is respectively connected to the input end of the amplifier circuit of the driving circuit and one end of the resonant capacitor, and the other end of the resonant capacitor is connected to the reference ground of the power supply of the driving circuit; wherein, The resonant circuit is in an underdamped state and is used to output a reference voltage of the amplifier circuit; wherein the reference voltage is a voltage with a preset change rate; Wherein, the drive circuit further includes: a feedforward circuit, which includes: a transient voltage suppression diode, a feedforward capacitor, a first feedforward resistor, a second feedforward resistor, a first diode and a second diode; wherein, the cathode of the transient voltage suppression diode is connected to the drain or collector of the power semiconductor device, the anode of the transient voltage suppression diode is connected to one end of the feedforward capacitor, the other end of the feedforward capacitor is respectively connected to one end of the first feedforward resistor and the anode of the first diode, the cathode of the first diode is connected to one end of the second feedforward resistor, the other end of the second feedforward resistor is connected to the gate of the power semiconductor device, the other end of the first feedforward resistor is connected to the cathode of the second diode, and the anode of the second diode is connected to the second power supply of the power supply; wherein, The feedforward circuit is used to charge the gate capacitance of the power semiconductor device to reduce the rate of decrease of the gate voltage of the power semiconductor device when the power semiconductor device is turned off; The feedforward circuit is further configured to discharge the feedforward capacitor when the power semiconductor device is turned on.

2. The circuit according to claim 1, characterized in that The resonant circuit further includes: a voltage stabilizing circuit; one end of the voltage stabilizing circuit is connected to the input end of the amplifier circuit, and the other end of the voltage stabilizing circuit is connected to the reference ground; wherein, The voltage stabilizing circuit is used to clamp the reference voltage so that the reference voltage falls within a preset voltage range.

3. The circuit according to claim 2, characterized in that The voltage stabilizing circuit includes: a first voltage stabilizing tube and a second voltage stabilizing tube; wherein, The anode of the first voltage-stabilizing tube is connected to the anode of the second voltage-stabilizing tube, the cathode of the first voltage-stabilizing tube is connected to the input end of the amplifier circuit, and the cathode of the second voltage-stabilizing tube is connected to the reference ground.

4. The circuit according to any one of claims 1 to 3, characterized in that The capacitance value of the resonant capacitor is positively correlated with the ratio of the gate capacitance of the power semiconductor device to the amplification factor of the transistor in the amplifier circuit.

5. The circuit according to any one of claims 1 to 3, characterized in that The inductance of the resonant inductor is inversely correlated with the product of the square of the angular frequency of the resonant circuit and the capacitance of the resonant capacitor.

6. The circuit according to any one of claims 1 to 3, characterized in that The resistance value of the resonant resistor is positively correlated with the product of the square root of the ratio of the inductance value of the resonant inductor to the capacitance value of the resonant capacitor and the damping ratio of the resonant circuit.

7. The circuit according to claim 1, wherein: The damping ratio of the resonant circuit is greater than or equal to 0.2 and less than or equal to 0.

5.

8. The circuit according to claim 1, wherein: The feedforward circuit further includes: a transistor, a third diode, a third feedforward resistor and a fourth feedforward resistor; wherein, The third feed-forward resistor is arranged between the first feed-forward resistor and the second diode, the base of the transistor is connected to the connection point of the first feed-forward resistor and the third feed-forward resistor, the collector of the transistor is connected to the positive electrode of the first power supply of the power supply, the emitter of the transistor is connected to the cathode of the second diode, one end of the fourth feed-forward resistor is connected to the anode of the third diode, the other end of the fourth feed-forward resistor is connected to the emitter of the transistor, and the cathode of the third diode is connected to one end of the resonant capacitor; The feedforward circuit is used for charging the resonant capacitor after the current amplified by the transistor flows through the fourth feedforward resistor and the third diode when the power semiconductor device is turned off, so as to reduce the falling rate of the reference voltage.

9. The circuit according to claim 8, characterized in that The feedforward circuit further includes: a fourth diode, the anode of the fourth diode is connected to the base of the transistor, and the cathode of the fourth diode is connected to the collector of the transistor; wherein, The fourth diode is used to clamp the base voltage of the transistor to the power supply voltage of the first power supply.

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