Power switching device driving circuit

Abstract

The utility model discloses a power switch device driving circuit, and relates to the technical field of power electronics, and the circuit comprises a driving chip module which is used for generating a driving signal; the driving power supply module is used for generating power supply voltage; the charging and discharging module is connected with the driving power supply module and is used for adjusting the amplitude of the power supply voltage through charging and discharging and outputting variable power supply voltage; the push-pull module is respectively connected with the driving chip module and the charging and discharging module and is used for generating a variable driving signal according to the driving signal and the variable power supply voltage; the switch module is connected with the push-pull module, and the switch module is used for driving the power switch device to execute switching action according to the variable driving signal; and the control module is respectively connected with the driving power supply module, the charging and discharging module and the push-pull module through the driving chip module, and is used for outputting a control signal and controlling the driving power supply module, the charging and discharging module and the push-pull module to work. According to the invention, the structure complexity of the power switch device driving circuit can be reduced, so that the miniaturization design of products is realized.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and particularly to a driving circuit for a power switch device. Background Art

[0002] In the related art, generally, a circuit composed of n groups of switches and resistors is respectively used to control the gate resistance value of the driving loop in each stage of the switching process, so as to control the change speed of the current and voltage in different transient stages during the switching process, and to realize the coordinated regulation of multiple characteristic quantities of the power switch device during the switching process. However, the above circuit will lead to a relatively large number of switches and resistors added in the entire driving system, with a complex structure, which is not conducive to the miniaturization of products. Summary of the Utility Model

[0003] The main purpose of this application is to provide a driving circuit for a power switch device, aiming to solve the technical problem of the complex structure of the driving circuit for the power switch device in the related art.

[0004] To achieve the above object, this application proposes a driving circuit for a power switch device, including:

[0005] A driving chip module for generating a driving signal;

[0006] A driving power supply module for generating a supply voltage;

[0007] A charge and discharge module connected to the driving power supply module, for adjusting the amplitude of the supply voltage through charge and discharge to output a variable supply voltage;

[0008] A push-pull module respectively connected to the driving chip module and the charge and discharge module, for generating a variable driving signal according to the driving signal and the variable supply voltage;

[0009] A switching module connected to the push-pull module, the switching module includes a power switch device, and the switching module is used to drive the power switch device to perform a switching action according to the variable driving signal;

[0010] A control module is respectively connected to the driving power supply module, the charge and discharge module and the push-pull module through the driving chip module, for outputting a control signal to control the operation of the driving power supply module, the charge and discharge module and the push-pull module.

[0011] In one embodiment, the charge and discharge module includes an inductor L1, an inductor L2, a diode D3, a diode D4, a field effect transistor Q3, a capacitor C6, a capacitor C7 and a resistor R5;

[0012] One end of the inductor L1 is connected to the drive power supply module, the other end of the inductor L1 is connected to the anode of the diode D3, the cathode of the diode D3 is respectively connected to one end of the resistor R5, one end of the capacitor C6 and the push-pull module, the other end of the resistor R5 is connected to the drain of the field effect transistor Q3, one end of the inductor L2 is connected to the drive power supply module, the other end of the inductor L2 is connected to the cathode of the diode D4, the anode of the diode D4 is respectively connected to the source of the field effect transistor Q3, one end of the capacitor C7 and the push-pull module, the gate of the field effect transistor Q3 is connected to the control module through the drive chip module, and the other ends of the capacitor C6 and the capacitor C7 are grounded.

[0013] In one embodiment, the push-pull module includes a resistor R6, a resistor R7, a resistor R8, a field effect transistor Q4 and a field effect transistor Q5;

[0014] One end of the resistor R6 and one end of the resistor R7 are both connected to the control module through the drive chip module, the other end of the resistor R6 is connected to the gate of the field effect transistor Q4, the source of the field effect transistor Q4 is connected to the charge and discharge module, the other end of the resistor R7 is connected to the gate of the field effect transistor Q5, the source of the field effect transistor Q5 is connected to the charge and discharge module, the drains of the field effect transistor Q4 and the field effect transistor Q5 are both connected to one end of the resistor R8, and the other end of the resistor R8 is connected to the switch module.

[0015] In one embodiment, the drive power supply module includes an open-loop push-pull unit and a transformer unit;

[0016] The open-loop push-pull unit is used to generate an AC inverter signal;

[0017] The primary side of the transformer unit is connected to the open-loop push-pull unit, the secondary side of the transformer unit is connected to the charge and discharge module, and the transformer unit is used to generate a supply voltage according to the AC inverter signal.

[0018] In one embodiment, the open-loop push-pull unit includes a field effect transistor Q1, a field effect transistor Q2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a capacitor C2 and a capacitor C3;

[0019] The drain of the field effect transistor Q1 is respectively connected to one end of the resistor R2, one end of the resistor R3 and the primary side of the transformer unit, the gate of the field effect transistor Q1 is connected to the control module, the drain of the field effect transistor Q2 is respectively connected to one end of the resistor R1, one end of the resistor R4 and the primary side of the transformer unit, the gate of the field effect transistor Q2 is connected to the control module, the other end of the resistor R3 is connected to the other end of the resistor R4, the common connection point of the resistor R3 and the resistor R4 is respectively connected to the primary side of the transformer unit, one end of the capacitor C3 and the external power supply V1, the other end of the capacitor C3 is grounded, the other end of the resistor R2 is grounded through the capacitor C2, the other end of the resistor R1 is grounded through the capacitor C1, and the sources of the field effect transistor Q1 and the field effect transistor Q2 are both grounded.

[0020] In one embodiment, the voltage conversion unit includes a transformer T1, a diode D1, a diode D2, a capacitor C4, and a capacitor C5;

[0021] The tap of the primary coil of the transformer T1 is connected to the other end of the resistor R3, one end of the primary coil of the transformer T1 is connected to one end of the resistor R3, one end of the secondary coil of the transformer T1 is connected to the anode of the diode D1, the cathode of the diode D1 is respectively connected to one end of the capacitor C4 and the charge and discharge module, the other end of the primary coil of the transformer T1 is connected to one end of the resistor R4, the other end of the secondary coil of the transformer T1 is connected to the cathode of the diode D2, the anode of the diode D2 is respectively connected to one end of the capacitor C5 and the charge and discharge module, and the tap of the secondary coil of the transformer T1, the other end of the capacitor C4, and the other end of the capacitor C5 are all grounded.

[0022] In one embodiment, the switch module includes a resistor R9, a capacitor C8, a capacitor C9, a capacitor C10, an inductor L3, an inductor L4, and a field effect transistor Q6;

[0023] One end of the resistor R9 is connected to the push-pull module, the other end of the resistor R9 is respectively connected to one end of the capacitor C8, one end of the capacitor C9, and the gate of the field effect transistor Q6, the other end of the capacitor C8 is respectively connected to the drain of the field effect transistor Q6 and one end of the capacitor C10, the other end of the capacitor C9 is respectively connected to the source of the field effect transistor Q6 and the other end of the capacitor C10, the drain of the field effect transistor Q6 is connected to one end of the inductor L3, the source of the field effect transistor Q6 is connected to one end of the inductor L4, and the other ends of the inductor L3 and the inductor L4 are respectively connected to the switch application circuit to control the on and off of the switch application circuit.

[0024] One or more technical solutions proposed in this application have at least the following technical effects:

[0025] In a power switch device driving circuit provided in this application, the power switch device driving circuit includes a driving chip module for generating a driving signal; a driving power supply module for generating a supply voltage; a charge and discharge module connected to the driving power supply module, which can adjust the amplitude of the supply voltage through charge and discharge to output a variable supply voltage; a push-pull module respectively connected to the driving chip module and the charge and discharge module for generating a variable driving signal according to the driving signal and the variable supply voltage; a switch module connected to the push-pull module, the switch module includes a power switch device, and the switch module is used to drive the power switch device to perform a switching action according to the variable driving signal; a control module is respectively connected to the driving power supply module, the charge and discharge module, and the push-pull module through the driving chip module for outputting a control signal to control the operation of the driving power supply module, the charge and discharge module, and the push-pull module.

[0026] In the power switch device driving circuit of the present application, the charge and discharge module can adjust the amplitude of the supply voltage by means of charge and discharge to generate a variable supply voltage. This variable supply voltage can be combined with a driving signal and processed by a push-pull module to generate a variable driving signal for driving the power switch device in the switch module to perform a switching action. Compared with the circuit composed of n groups of switches and resistors in the related art, which controls the gate resistance value at each stage of the switching process in the driving loop to realize the control of the switching process, the driving circuit provided by the present application can dynamically adjust the amplitude of the driving signal in the form of charge and discharge, so that the performance of the power switch device can always be at an optimal value within an acceptable range during the switching process. The overall circuit structure is concise, which is convenient for realizing the miniaturization of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with the present application and, together with the specification, are used to explain the principles of the present application.

[0028] To more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the drawings required for use in the description of the embodiments or the related art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a schematic structural diagram provided for the first embodiment of the power switch device driving circuit of the present application;

[0030] Figure 2 It is a schematic structural diagram provided for the second embodiment of the power switch device driving circuit of the present application;

[0031] Figure 3 It is a detailed circuit schematic diagram of the power switch device driving circuit of the present application;

[0032] Figure 4 It is a schematic flow chart provided for the first embodiment of the power switch device driving method of the present application;

[0033] Figure 5 It is a schematic diagram of the switching trajectory of the power switch device in the CGD driving mode;

[0034] Figure 6 It is a schematic diagram of the voltage control of the charge and discharge module;

[0035] Figure 7 It is an actual measurement diagram of the waveform during the control process of the SiC MOSFET.

[0036] The realization of the purpose, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] Next, in combination with the accompanying drawings in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present application.

[0038] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present application, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0039] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel scenarios. Taking "A and / or B" as an example, it includes scenario A, scenario B, or the scenario where A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present application.

[0040] In the field of new energy vehicles, power switch devices are often used in automotive electronic control products, and the driving of power switch devices is basically CGD (Conventional Gate Driver, traditional gate driving mode). However, it is difficult to ensure the switching speed of power switch devices during CGD driving. Therefore, a more advanced AGD (Active Gate Driver, active gate driving mode) has emerged. AGD can dynamically adjust the speed of power switch devices in each working area to make it always at the optimal value within the acceptable range of the device and the system, so as to achieve the balance of efficiency improvement, device safety, and EMI control.

[0041] In the related art, AGD generally uses circuits composed of n groups of switches and resistors respectively to control the gate resistance value of the driving circuit at each stage of the switching process, and then realizes the control of the current and voltage change speeds in different transient stages during the switching process, so as to realize the coordinated regulation of multiple characteristic quantities of the power switch device during the switching process. However, the above circuit will lead to a relatively large number of switches and resistors added in the entire driving system, with a complex structure, which is not conducive to the miniaturization of products.

[0042] To solve this technical problem, a driving circuit for a power switch device according to the present application is proposed. The charging and discharging module can adjust the amplitude of the power supply voltage of the driving chip by charging and discharging to generate a variable power supply voltage. The variable power supply voltage can be combined with the driving signal output by the driving chip and processed by the push-pull module to generate a variable driving signal for driving the power switch device in the switching module to perform a switching action. Compared with the circuit composed of n groups of switches and resistors respectively in the related art, which controls the gate resistance value of the driving circuit at each stage of the switching process to realize the control of the switching process, the driving circuit provided by the present application can dynamically regulate the amplitude of the driving signal in the form of charging and discharging, so that the performance of the power switch device can always be at a better value within an acceptable range during the switching process. The overall circuit structure is concise, which is convenient for realizing the miniaturization of products.

[0043] The following will be described and introduced through multiple embodiments.

[0044] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of the first embodiment of the driving circuit for the power switch device of the present application.

[0045] In this embodiment, the driving circuit for the power switch device includes:

[0046] A driving chip module for generating a driving signal;

[0047] A driving power supply module for generating a power supply voltage;

[0048] A charging and discharging module, connected to the driving power supply module, for adjusting the amplitude of the power supply voltage by charging and discharging and outputting a variable power supply voltage;

[0049] A push-pull module, respectively connected to the driving chip module and the charging and discharging module, for generating a variable driving signal according to the driving signal and the variable power supply voltage;

[0050] A switching module, connected to the push-pull module, the switching module includes a power switch device, and the switching module is used to drive the power switch device to perform a switching action according to the variable driving signal;

[0051] The control module is connected to the drive power module, the charge and discharge module, and the push-pull module through the drive chip module respectively, and is used to output control signals to control the operation of the drive power module, the charge and discharge module, and the push-pull module.

[0052] Specifically, the drive chip module can generate and output drive signals, and the drive chip module can integrate multiple drive chips; the drive power module can generate a stable supply voltage according to the control signal of the control module to provide a drive voltage for the drive chips. The control module can be a control chip such as an FGPA (Field-Programmable Gate Array). The drive power module can be a switching regulated power supply to ensure a stable supply voltage output. Or as a feasible implementation, referring to Figure 2 , Figure 2 shows a detailed structural schematic diagram of the first embodiment of the power switch device drive circuit. In this implementation, the drive power module can include an open-loop push-pull unit and a transformer unit;

[0053] The open-loop push-pull unit can be used to generate an AC inverter signal;

[0054] The primary side of the transformer unit is connected to the open-loop push-pull unit, and the secondary side of the transformer unit is connected to the charge and discharge module. The transformer unit is used to generate a supply voltage according to the AC inverter signal.

[0055] The open-loop push-pull unit can receive a control signal from the control module through the drive chip IC2 of the drive chip module and generate an AC inverter signal through its internal push-pull structure. The primary side of the transformer unit is connected to the open-loop push-pull unit, and the secondary side of the transformer is connected to the charge and discharge module. Thus, the transformer unit can generate a corresponding supply voltage on the secondary side according to the AC inverter signal input on the primary side. The supply voltage can be further processed by the charge and discharge module connected to the transformer unit.

[0056] In a feasible implementation, referring to Figure 3 , Figure 3 shows the detailed circuit schematic diagram of the power switch device drive circuit of the present application. As Figure 3 shown, the open-loop push-pull unit can include a field effect transistor Q1, a field effect transistor Q2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a capacitor C2, and a capacitor C3;

[0057] The drain of field effect transistor Q1 is respectively connected to one end of resistor R2, one end of resistor R3, and the primary side of the transformer unit. The gate of field effect transistor Q1 is connected to the control module. The drain of field effect transistor Q2 is respectively connected to one end of resistor R1, one end of resistor R4, and the primary side of the transformer unit. The gate of field effect transistor Q2 is connected to the control module. The other end of resistor R3 is connected to the other end of resistor R4. The common connection point of resistor R3 and resistor R4 is respectively connected to the primary side of the transformer unit, one end of capacitor C3, and external power supply V1. The other end of capacitor C3 is grounded. The other end of resistor R2 is grounded through capacitor C2. The other end of resistor R1 is grounded through capacitor C1. The source electrodes of field effect transistor Q1 and field effect transistor Q2 are both grounded.

[0058] The transformer unit may include transformer T1, diode D1, diode D2, capacitor C4, and capacitor C5;

[0059] The tap of the primary coil of transformer T1 is connected to the other end of resistor R3. One end of the primary coil of transformer T1 is connected to one end of resistor R3. One end of the secondary coil of transformer T1 is connected to the anode of diode D1. The cathode of diode D1 is respectively connected to one end of capacitor C4 and the charge and discharge module. The other end of the primary coil of transformer T1 is connected to one end of resistor R4. The other end of the secondary coil of transformer T1 is connected to the cathode of diode D2. The anode of diode D2 is respectively connected to one end of capacitor C5 and the charge and discharge module. The tap of the secondary coil of transformer T1, the other end of capacitor C4, and the other end of capacitor C5 are all grounded.

[0060] Specifically, the gates of field effect transistor Q1 and field effect transistor Q2 in the open-loop push-pull unit can both be connected to the control module. The control module can output control signals for the gates of the field effect transistors ( Figure 3 GATE_Q1 and GATE_Q2 in wherein, V out is the output voltage value of the secondary side of transformer T1, V in is the input voltage value of the primary side of transformer T1 ( Figure 3 V1 in M is the conduction voltage drop value of the field effect transistors (Q1, Q2) in the open-loop push-pull unit connected to the primary side of transformer T1, V D is the conduction voltage drop value of the diodes (D1, D2) on the secondary side of transformer T1, N sis the number of turns of the secondary side winding of transformer T1, N P is the number of turns of the primary side winding of transformer T1, T ON is the conduction time of the field effect transistor in the push - pull unit, and T is the period of the alternating conduction of the field effect transistor. It can be seen from the above formula that when the input voltage is determined and the device types in the open - loop push - pull unit and the transformer unit are determined, the amplitude of the output voltage (i.e., the supply voltage) on the secondary side of the transformer can be adjusted by the conduction duty cycle of the field effect transistor. In this embodiment, the output positive voltage of the drive signal can be adjusted to + 17V, and the output negative voltage of the drive signal can be adjusted to - 4.5V. In addition, in the above circuit structure, capacitor C4 and capacitor C5 are voltage - stabilizing capacitors, which can perform voltage - stabilizing processing on the output voltage of transformer T1 to ensure the stability of the supply voltage.

[0061] After obtaining the supply voltage by using the drive power module, charge - discharge processing can be performed based on the supply voltage through the charge - discharge module connected to the drive power module to achieve the purpose of adjusting the amplitude of the supply voltage and obtain a variable supply voltage. The variable supply voltage and the drive signal output by the drive chip module can obtain a variable drive signal after being processed by the push - pull module, and this variable drive signal can be used to drive the power switching device in the above - mentioned switching module to perform switching actions.

[0062] In a feasible implementation manner, as Figure 3 shown, the charge - discharge module may include inductor L1, inductor L2, diode D3, diode D4, field effect transistor Q3, capacitor C6, capacitor C7, and resistor R5;

[0063] One end of inductor L1 is connected to the drive power module, the other end of inductor L1 is connected to the anode of diode D3, the cathode of diode D3 is respectively connected to one end of resistor R5, one end of capacitor C6, and the push - pull module, the other end of resistor R5 is connected to the drain of field effect transistor Q3, one end of inductor L2 is connected to the drive power module, the other end of inductor L2 is connected to the cathode of diode D4, the anode of diode D4 is respectively connected to the source of field effect transistor Q3, one end of capacitor C7, and the push - pull module, the gate of field effect transistor Q3 is connected to the control module through the drive chip module, and the other ends of capacitor C6 and capacitor C7 are grounded.

[0064] Specifically, the drive chip module may include an isolated drive chip IC1, and the control signal output by the control module (such as Figure 3The shown AGD_1 signal can be input to the gate of the field effect transistor Q3 through the isolation drive chip IC1 to control the conduction or cut-off of the field effect transistor Q3. When the field effect transistor Q3 is conducting, the inductors L1 and L2 can cooperate with the diodes D3 and D4 to form a charging circuit, and the inductors L1 and L2 store electrical energy. When the field effect transistor Q3 is cut off, the electrical energy stored in the inductors L1 and L2 is released. During the charge and discharge process, the supply voltage can change in real time as the charge and discharge process progresses, and thus a variable supply voltage can be obtained. The capacitors C6 and C7 can filter out some signal noise interference to maintain the stability of the circuit. In some cases, they can also be used to temporarily store or release electrical energy. The resistor R5 is a current limiting resistor, which can prevent the circuit current from changing suddenly and excessively during the charging process, affecting the circuit stability or damaging other components. The drive chip module may further include an isolation drive chip IC3. The isolation drive chip IC3 is the drive chip of the power switch device in the switch module. The control module can output an initial drive signal, and after passing through the isolation drive chip IC3, a drive signal can be output to the push-pull module. The push-pull module can generate a variable drive signal according to the variable supply voltage output by the charge and discharge module and the drive signal output by the drive chip to drive the power switch device of the switch module to perform a switching action.

[0065] In a feasible implementation manner, as Figure 3 shown, the push-pull module may include a resistor R6, a resistor R7, a resistor R8, a field effect transistor Q4, and a field effect transistor Q5;

[0066] One end of the resistor R6 and one end of the resistor R7 are both connected to the control module through the drive chip module. The other end of the resistor R6 is connected to the gate of the field effect transistor Q4. The source of the field effect transistor Q4 is connected to the charge and discharge module. The other end of the resistor R7 is connected to the gate of the field effect transistor Q5. The source of the field effect transistor Q5 is connected to the charge and discharge module. The drains of the field effect transistor Q4 and the field effect transistor Q5 are both connected to one end of the resistor R8, and the other end of the resistor R8 is connected to the switch module.

[0067] Specifically, the gates of the field effect transistor Q4 and the field effect transistor Q5 are respectively connected to the isolation drive chip IC3 in the above drive chip module through the resistors R6 and R7, and then connected to the control module through the isolation drive chip IC3. The control module can output an initial drive signal, and after passing through IC3, a drive signal can be output (such as Figure 3in PWM_Vgs_1) to control the on or off states of field effect transistor Q4 and field effect transistor Q5. When field effect transistor Q4 is on, field effect transistor Q5 is off. At this time, the positive output voltage (forward power supply voltage) of the charge and discharge module can be input to the gate of the power switch device to turn on the power switch device. When field effect transistor Q4 is off, field effect transistor Q5 is on. At this time, the negative output voltage (negative power supply voltage) of the charge and discharge module can be input to the gate of the power switch device to turn off the power switch device. The above-mentioned field effect transistor Q4 can be a P-channel enhancement type field effect transistor, and field effect transistor Q5 can be an N-channel enhancement type field effect transistor. It should be noted that Figure 3 V2 and V3 shown in are the output points of the drive power supply module. The isolated drive chip IC3 can obtain power from V2 and V3. V4 and V5 are the output points of the charge and discharge module, and the push-pull module can obtain power from V4 and V5.

[0068] In addition, as Figure 3 shown, the switch module can include resistor R9, capacitor C8, capacitor C9, capacitor C10, inductor L3, inductor L4, and field effect transistor Q6;

[0069] One end of resistor R9 is connected to the push-pull module. The other end of resistor R9 is respectively connected to one end of capacitor C8, one end of capacitor C9, and the gate of field effect transistor Q6. The other end of capacitor C8 is respectively connected to the drain of field effect transistor Q6 and one end of capacitor C10. The other end of capacitor C9 is respectively connected to the source of field effect transistor Q6 and the other end of capacitor C10. The drain of field effect transistor Q6 is connected to one end of inductor L3. The source of field effect transistor Q6 is connected to one end of inductor L4. The other ends of inductor L3 and inductor L4 are respectively connected to the switch application circuit to control the on and off of the switch application circuit.

[0070] The above-mentioned resistor R9, capacitor C8, capacitor C9, capacitor C10, inductor L3, inductor L4, and field effect transistor Q6 can form an equivalent model of the power switch device. During the turn-on and turn-off processes of the power switch device (such as a silicon carbide metal-oxide-semiconductor field effect transistor SiC MOSFET), the charging speeds of the input capacitance Ciss, output capacitance Coss, and reverse transfer capacitance Crss of the power switch device are mainly adjusted by adjusting the gate of the power switch device to adjust the various characteristics during the switching process of the power switch device. Among them, Ciss = C8 + C9, Coss = C8 + C10, Crss = C8; the formula for the capacitor charging voltage and time is as follows: In the formula, V t is the voltage value at time t, V 0V is the power supply voltage value for charging the capacitor (i.e., the gate drive voltage of the power switch device), R is the value of the gate drive resistance (i.e., the resistance value of R8 + R9), C is the junction capacitance value of the power switch device (Ciss, Coss, and Crss), and t is the charging time. When the gate drive resistance and the junction capacitance of the power switch device are determined, by adjusting the amplitude of the gate drive voltage (i.e., the drive signal), the voltage and current change rates in different working regions during the turn-on process of the power switch device can be directly controlled, achieving a balance between the losses, current overshoot, and vibration during the turn-on process. Similarly, by adjusting the amplitude of the gate drive voltage (i.e., the drive signal), the balance between the losses, overshoot, and oscillation during the turn-off process of the power switch device can also be achieved.

[0071] It can be seen from this that in the power switch device drive circuit provided in this embodiment, the amplitude of the power supply voltage can be adjusted by the charge and discharge module through the charge and discharge method to generate a variable power supply voltage. This variable power supply voltage is combined with the drive signal and can generate a variable drive signal after being processed by the push-pull module, so as to drive the power switch device in the switch module to perform the switch action. Instead of using a circuit composed of n groups of switches and resistors respectively to control the gate resistance value at each stage of the switch process of the drive loop to achieve the control of the switch process of the power switch device, the power switch device drive circuit provided in this embodiment dynamically adjusts the amplitude of the drive signal in the form of charge and discharge, so that the performance of the power switch device can always be at a better value within an acceptable range during the switch process. The overall circuit structure is concise and it is convenient to realize the miniaturization of the product.

[0072] Furthermore, an embodiment of the present application provides a method for driving a power switch device, which can be used for the power switch device drive circuit as described above. Refer to Figure 4 , Figure 4 which shows the schematic flow chart of the first embodiment of the method for driving a power switch device of the present application.

[0073] In this embodiment, the method for driving a power switch device includes steps S100 to S600:

[0074] Step S100, output a control signal through the control module.

[0075] Step S200, output a drive signal through the drive chip module.

[0076] Step S300, generate a power supply voltage according to the control signal through the drive power supply module.

[0077] Step S400, use the charge and discharge module to adjust the amplitude of the power supply voltage by charge and discharge, and output a variable power supply voltage.

[0078] Step S500, generate a variable drive signal according to the drive signal and the variable power supply voltage through the push-pull module.

[0079] Step S600: Drive the power switch device to perform a switching action according to the variable drive signal through the switch module.

[0080] Specifically, the control module can output a control signal to the drive power module so that the drive power module can generate a stable supply voltage accordingly. For specific implementation details, refer to the embodiment part of the power switch device drive circuit, which will not be elaborated here. Then, by using the charge and discharge module connected to the drive power module, the amplitude of the supply voltage can be adjusted through charge and discharge to output a variable supply voltage. The variable supply voltage and the drive signal output by the drive chip module can be processed by the push-pull module to obtain a variable drive signal for driving the power switch device to perform a switching operation.

[0081] In a feasible implementation manner, step S400 may specifically include steps S410 to S440 to optimize the performance of the power switch device during the turn-on process.

[0082] Step S410: Receive the turn-on control instruction through the control module, and control the field effect transistor Q3 in the charge and discharge module to conduct according to the turn-on control instruction.

[0083] Step S420: When the power switch device starts to enter the turn-on process, control the field effect transistor Q3 to turn off.

[0084] Step S430: When the gate-source voltage value of the power switch device is greater than the preset turn-on voltage value and close to the Miller plateau voltage value, control the field effect transistor Q3 to conduct;

[0085] Step S440: When the power switch device starts to enter the current-voltage oscillation process, control the field effect transistor Q3 to turn off so that the variable drive signal received by the switch module is stabilized within the first preset voltage range and turn on the power switch device.

[0086] In another feasible implementation manner, step S400 may also specifically include steps S450 to S480 to optimize the performance of the power switch device during the turn-off process.

[0087] Step S450: Receive the turn-off control instruction through the control module, and control the field effect transistor Q3 in the charge and discharge module to conduct according to the turn-off control instruction.

[0088] Step S460: When the power switch device starts to enter the turn-off process, control the field effect transistor Q3 to turn off.

[0089] Step S470: When the gate-source voltage value of the power switch device is close to the Miller plateau voltage value, control the field effect transistor Q3 to conduct.

[0090] Step S480: When the power switch device starts to enter the current-voltage oscillation process, control the field-effect transistor Q3 to turn off, so that the variable drive signal received by the switching module is stabilized within the second preset voltage range, and turn off the power switch device.

[0091] It can be understood that while the faster switching speed of the power switch device brings about a reduction in switching losses, the voltage and current overshoots caused by higher voltage and current change rates will also affect the stability of the power switch device. In the CGD drive mode, the switching trajectory of the power switch device is as Figure 5 shown, Figure 5 where, V EE is the output negative voltage (negative power supply voltage) of the drive signal, V CC is the output positive voltage (positive power supply voltage) of the drive signal, V th is the conduction threshold value of the power switch device (i.e., the preset conduction voltage value), V mp is the Miller plateau voltage value. Region I (t 0 -t 1 ) and Region V (t 5 -t 6 ) respectively represent the turn-on delay and turn-off delay processes of the power switch device. As can be seen from Figure 5 , there is no obvious change in the voltage and current of the power switch device in Region I and Region V, but the duration of these two intervals directly affects the switching speed and dead-time setting of the power switch device. Therefore, the time in this interval should be as short as possible. Region III (t 2 -t 3 ) and Region VII (t 7 -t 8 ) are respectively the current overshoot region during the turn-on process and the voltage overshoot region during the turn-off process. The overshoot voltage and current amplitudes are jointly determined by the parasitic parameters of the power loop and and . Among them, is the rate of change of the drain-source current i ds with time t, is the rate of change of the drain-source voltage v ds with time t, which needs to be strictly controlled within the safe operating area of the device. Regions IV and VIII are the oscillation regions of current and voltage. When the parasitic parameters of the power loop are determined, the magnitude of the oscillation amplitude is determined by in Region III and Each makes its own decision, and the oscillation amplitude needs to be strictly controlled within the system EMI and device tolerance range. Region II and Region VI are the linear rising regions of current and voltage respectively, and are the key control regions for decoupling switch time, switching loss, current, voltage overshoot and oscillation. The quality of control determines the specific effects of reducing switching loss, minimizing current and voltage overshoot and oscillation, reducing EMI (electromagnetic interference) and inter-phase crosstalk. From the above analysis, it is not difficult to know that the switching speed in Region II, Region III, Region VI and Region VII directly determines the turn-on and turn-off losses of the power device. From the perspective of loss, the shorter the time in these four regions, the lower the switching loss of the power device, which is more conducive to improving the system efficiency. However, from the perspective of device tolerance and system EMI, the longer the time in these four regions, the smaller the current and voltage stress of the power device, which is more conducive to device safety and system EMI control. Therefore, it is necessary to dynamically adjust the above regions to achieve the best performance of the power switch device.

[0092] Specifically, the control module can receive an external conduction control instruction for the power switch device. The control module can control the field effect transistor Q3 in the charging module to conduct according to the conduction control instruction, that is, before the switching trajectory enters Region I, control the field effect transistor Q3 to conduct, forming a charging circuit. The inductor in the circuit stores energy. At this time, the supply voltage can drop from 21.5V to 15V. The drop of the supply voltage causes the gate-source voltage v gs amplitude to rise from -4.5V to -3V; when the power switch device starts to enter the turn-on process, that is, v gs enters Region I (t 0 - t 1 ), the field effect transistor Q3 can be controlled to turn off. At this time, the circuit formed by the field effect transistor Q3 is disconnected, and the inductor electrical energy is released, causing the supply voltage to rise from 15V to 23V. The rise of the supply voltage causes the reference voltage amplitude of v gs to rise from +12V to +18V, thereby shortening the time of the power switch device in Region I and Region II. When the gate-source voltage value of the power switch device is greater than the preset conduction voltage value and close to the Miller plateau voltage value, the field effect transistor Q3 can be controlled to conduct. At this time, the inductor stores energy again, and the supply voltage drops again. The amplitude of v gs in the Miller plateau slows down the rising speed due to the drop of the supply voltage amplitude. Thus, the time of the power switch device in Region III (t 2 - t 3 ) is extended, and the drain-source current i ds in Region III (t 2 - t 3)The amplitudes of overshoot and oscillation in Region IV both decrease. When the power switching device starts to enter the current-voltage oscillation process (entering Region IV), the field-effect transistor Q3 can be controlled to turn off again, so that the amplitude of the variable drive signal received by the switching module can be stabilized within the first preset voltage range. After the field-effect transistor Q3 turns off, the inductive energy storage is released again, causing v gs The amplitude rises again and finally stabilizes at +17V, completing the conduction process of the power switching device.

[0093] As Figure 6 shown, Figure 6 Figure 9 is a schematic diagram of the voltage adjustment process of the charge and discharge module. Figure 6 The load loop control PWM in gs is the AGD_1 signal applied to the field-effect transistor Q3. Similarly, the control module can receive an external turn-off control instruction for the power switching device, and the control module can control the field-effect transistor Q3 in the charging module to turn on according to the turn-off control instruction, that is, before the switching trajectory enters Region V, control the field-effect transistor Q3 to turn on to form a charging loop. The inductive energy storage in the loop, at this time, the supply voltage can drop from 21.5V to 15V. The drop in the supply voltage causes the gate-source voltage v gs of the switching power device to drop from +17V to +12V; when the power switching device starts to enter the turn-off process, that is, v 5 enters Region V (t 6 -t gs ), the field-effect transistor Q3 can be controlled to turn off. At this time, the loop formed by the field-effect transistor Q3 is disconnected, and the inductive electrical energy is released, causing the supply voltage to rise from 15V to 23V. The rise in the supply voltage causes the amplitude of the Vgs reference voltage to drop from -3V to -5V, thereby shortening the time of the power switching device in Region V and Region VI. When the gate-source voltage value of the power switching device is close to the Miller plateau voltage value, the field-effect transistor Q3 can be controlled to turn on. At this time, the inductor stores energy again, the supply voltage drops again, and the drop speed of the v 7 amplitude slows down due to the drop in the supply voltage amplitude, causing the power switching device to be in Region VII (t 8 ) for a longer time. The amplitudes of overshoot in Region VII and oscillation in Region VIII both decrease. When the power switching device starts to enter the current-voltage oscillation process (entering Region VIII), the field-effect transistor Q3 can be controlled to turn off again, so that the amplitude of the variable drive signal received by the switching module can be stabilized within the second preset voltage range. After the field-effect transistor Q3 turns off, the inductive energy storage is released again, causing v ds amplitude to drop and finally stabilize at -4.5V, completing the conduction process of the power switching device. gs Figure 10 is a schematic diagram of the voltage adjustment process of the charge and discharge module.

[0094] It can be understood that in the power switch device driving method provided in this embodiment, a control signal can be output by a control module, a power supply voltage can be generated by a driving power supply module according to the control signal, the amplitude of the power supply voltage can be adjusted by a charge and discharge module using charge and discharge, and a variable power supply voltage can be output. The variable power supply voltage and the driving signal output by the driving chip module can be processed by a push-pull module to obtain a variable driving signal. Thus, the power switch device can be driven to perform a switching action according to the variable driving signal by a switching module. The control and implementation scheme of the circuit is relatively concise, which is convenient for realizing the miniaturized design of the driving circuit product.

[0095] In addition, in order to verify the effectiveness of the power switch device driving method in this embodiment, taking SiC MOSFET as an example, various signal waveforms were measured in real time during the control process, such as Figure 7 shown. Channel 1 is the turn-off voltage of the SiC MOSFET, channel 2 is the turn-on voltage of the SiC MOSFET, and channel 3 is the AGD control signal of the field effect transistor Q3. Before the SiC MOSFET is turned on, the power supply voltage drops due to the conduction of the field effect transistor Q3 circuit, causing the reference voltage of v gs to rise from -4.5V to about -3V; when the SiC MOSFET enters region I, the circuit of the field effect transistor Q3 is disconnected, causing the reference voltage of Vgs to rise to about +18V; when the SiC MOSFET enters region III, the circuit of the field effect transistor Q3 conducts again, and the downward adjustment of the v gs reference voltage will slow down the rising speed of i ds and extend the time of the SiC MOSFET in region III; when the SiC MOSFET is in region IV, the circuit of the field effect transistor Q3 is disconnected again, causing the reference voltage of v gs to rise and finally stabilize at +17V, which is consistent with the theoretical situation.

[0096] The above are only some embodiments of the present application, and thus do not limit the patent scope of the present application. Any equivalent structural transformation made under the technical concept of the present application by using the content of the specification and drawings of the present application, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A power switch device driving circuit, characterized in that: The power switch device driving circuit comprises: A driving chip module, used for generating a driving signal; A driving power supply module, used for generating a supply voltage; A charge and discharge module, connected to the driving power supply module, for adjusting the amplitude of the supply voltage by charge and discharge, and outputting a variable supply voltage; A push-pull module, connected to the driving chip module and the charging and discharging module respectively, and used to generate a variable driving signal according to the driving signal and the variable supply voltage; A switch module, connected to the push-pull module, the switch module comprising a power switch device, and the switch module is used to drive the power switch device to perform a switching action according to the variable drive signal; The control module is respectively connected to the driving power module, the charging and discharging module and the push-pull module through the driving chip module, and is used to output a control signal to control the operation of the driving power module, the charging and discharging module and the push-pull module.

2. The power switch device driving circuit according to claim 1, characterized in that: The charging and discharging module includes an inductor L1, an inductor L2, a diode D3, a diode D4, a field effect transistor Q3, a capacitor C6, a capacitor C7 and a resistor R5; One end of the inductor L1 is connected to the driving power module, the other end of the inductor L1 is connected to the anode of the diode D3, the cathode of the diode D3 is respectively connected to one end of the resistor R5, one end of the capacitor C6 and the push-pull module, the other end of the resistor R5 is connected to the drain of the field effect tube Q3, one end of the inductor L2 is connected to the driving power module, the other end of the inductor L2 is connected to the cathode of the diode D4, the anode of the diode D4 is respectively connected to the source of the field effect tube Q3, one end of the capacitor C7 and the push-pull module, the gate of the field effect tube Q3 is connected to the control module through the driving chip module, and the other end of the capacitor C6 and the other end of the capacitor C7 are grounded.

3. The power switch device driving circuit according to claim 1, characterized in that: The push-pull module includes a resistor R6, a resistor R7, a resistor R8, a field effect transistor Q4 and a field effect transistor Q5; One end of the resistor R6 and one end of the resistor R7 are both connected to the control module through the driving chip module, the other end of the resistor R6 is connected to the gate of the field effect tube Q4, the source of the field effect tube Q4 is connected to the charging and discharging module, the other end of the resistor R7 is connected to the gate of the field effect tube Q5, the source of the field effect tube Q5 is connected to the charging and discharging module, the drain of the field effect tube Q4 and the drain of the field effect tube Q5 are both connected to one end of the resistor R8, and the other end of the resistor R8 is connected to the switch module.

4. The power switch device driving circuit according to claim 1, characterized in that: The driving power supply module includes an open-loop push-pull unit and a voltage transformation unit; The open-loop push-pull unit is used to generate an AC inverter signal; The primary side of the transformer unit is connected to the open-loop push-pull unit, the secondary side of the transformer unit is connected to the charge and discharge module, and the transformer unit is used to generate the supply voltage according to the AC inverter signal.

5. The power switch device driving circuit according to claim 4, characterized in that: The open-loop push-pull unit includes a field effect transistor Q1, a field effect transistor Q2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a capacitor C2 and a capacitor C3; The drain of the field effect tube Q1 is respectively connected to one end of the resistor R2, one end of the resistor R3 and the primary side of the transformer unit, the gate of the field effect tube Q1 is connected to the control module, the drain of the field effect tube Q2 is respectively connected to one end of the resistor R1, one end of the resistor R4 and the primary side of the transformer unit, the gate of the field effect tube Q2 is connected to the control module, the other end of the resistor R3 is connected to the other end of the resistor R4, the common point of the resistor R3 and the resistor R4 is respectively connected to the primary side of the transformer unit, one end of the capacitor C3 and the external power supply V1, the other end of the capacitor C3 is grounded, the other end of the resistor R2 is grounded through the capacitor C2, the other end of the resistor R1 is grounded through the capacitor C1, and the source of the field effect tube Q1 and the source of the field effect tube Q2 are both grounded.

6. The power switch device driving circuit according to claim 5, characterized in that: The voltage transformation unit includes a transformer T1, a diode D1, a diode D2, a capacitor C4 and a capacitor C5; The tap of the primary coil of the transformer T1 is connected to the other end of the resistor R3, one end of the primary coil of the transformer T1 is connected to one end of the resistor R3, one end of the secondary coil of the transformer T1 is connected to the anode of the diode D1, the cathode of the diode D1 is respectively connected to one end of the capacitor C4 and the charging and discharging module, the other end of the primary coil of the transformer T1 is connected to one end of the resistor R4, the other end of the secondary coil of the transformer T1 is connected to the cathode of the diode D2, the anode of the diode D2 is respectively connected to one end of the capacitor C5 and the charging and discharging module, and the tap of the secondary coil of the transformer T1, the other end of the capacitor C4 and the other end of the capacitor C5 are all grounded.

7. The power switch device driving circuit according to claim 1, characterized in that: The switch module includes a resistor R9, a capacitor C8, a capacitor C9, a capacitor C10, an inductor L3, an inductor L4 and a field effect transistor Q6; One end of the resistor R9 is connected to the push-pull module, the other end of the resistor R9 is respectively connected to one end of the capacitor C8, one end of the capacitor C9 and the gate of the field effect transistor Q6, the other end of the capacitor C8 is respectively connected to the drain of the field effect transistor Q6 and one end of the capacitor C10, the other end of the capacitor C9 is respectively connected to the source of the field effect transistor Q6 and the other end of the capacitor C10, the drain of the field effect transistor Q6 is connected to one end of the inductor L3, the source of the field effect transistor Q6 is connected to one end of the inductor L4, and the other end of the inductor L3 and the other end of the inductor L4 are respectively connected to the switch application circuit to control the on and off of the switch application circuit.

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