Power switching device driving circuit and method

Abstract

The invention discloses a power switch device driving circuit and method, 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 in particular to a power switching device driving circuit and method. Background Technology

[0002] In related technologies, circuits typically employ n sets of switches and resistors to control the gate resistance value of the drive circuit at each stage of the switching process. This allows for control of the rate of change of current and voltage during different transient stages of the switching process, enabling coordinated regulation of multiple characteristic quantities of the power switching device during switching. However, such circuits result in a large number of switches and resistors in the entire drive system, leading to a complex structure that is not conducive to product miniaturization. Summary of the Invention

[0003] The main objective of this application is to provide a power switching device driving circuit and method, aiming to solve the technical problem of complex structure of power switching device driving circuits in related technologies.

[0004] To achieve the above objectives, this application proposes a power switching device driving circuit, comprising:

[0005] The driver chip module is used to generate drive signals;

[0006] The driver power supply module is used to generate the power supply voltage;

[0007] The charging and discharging module, connected to the drive power module, is used to adjust the amplitude of the supply voltage through charging and discharging, and output a variable supply voltage.

[0008] The push-pull module is connected to the driver chip module and the charging / discharging module respectively, and is used to generate a variable drive signal based on the drive signal and the variable power supply voltage.

[0009] A switching module, connected to a push-pull module, includes power switching devices and is used to drive the power switching devices to perform switching actions according to a variable drive signal.

[0010] The control module is connected to the drive power module, charge / discharge module, and push-pull module respectively through the drive chip module. It is used to output control signals to control the operation of the drive power module, charge / discharge module, and push-pull module.

[0011] In one embodiment, the charging and discharging module includes inductor L1, inductor L2, diode D3, diode D4, field-effect transistor Q3, capacitor C6, capacitor C7, and resistor R5;

[0012] One end of inductor L1 is connected to the drive power module, and the other end of inductor L1 is connected to the anode of diode D3. The cathode of diode D3 is 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, and the other end of inductor L2 is connected to the cathode of diode D4. The anode of diode D4 is 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. The other ends of capacitors C6 and C7 are grounded.

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

[0014] One end of resistor R6 and one end of resistor R7 are both connected to the control module through the driver chip module. The other end of resistor R6 is connected to the gate of field-effect transistor Q4. The source of field-effect transistor Q4 is connected to the charging and discharging module. The other end of resistor R7 is connected to the gate of field-effect transistor Q5. The source of field-effect transistor Q5 is connected to the charging and discharging module. The drains of field-effect transistors Q4 and Q5 are both connected to one end of resistor R8. The other end of resistor R8 is connected to the switching module.

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

[0016] An open-loop push-pull unit is used to generate AC inverter signals;

[0017] 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 / discharge module. The transformer unit is used to generate the power supply voltage based on 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 MOSFET Q1 is connected to one end of resistor R2, one end of resistor R3, and the primary side of the transformer unit. The gate of MOSFET Q1 is connected to the control module. The drain of MOSFET Q2 is connected to one end of resistor R1, one end of resistor R4, and the primary side of the transformer unit. The gate of MOSFET Q2 is connected to the control module. The other end of resistor R3 is connected to the other end of resistor R4. The common junction of resistors R3 and R4 is connected to the primary side of the transformer unit, one end of capacitor C3, and the 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 sources of MOSFETs Q1 and Q2 are both grounded.

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

[0021] The tap of the primary winding of transformer T1 is connected to the other end of resistor R3. One end of the primary winding of transformer T1 is connected to one end of resistor R3. One end of the secondary winding of transformer T1 is connected to the anode of diode D1. The cathode of diode D1 is connected to one end of capacitor C4 and the charging / discharging module. The other end of the primary winding of transformer T1 is connected to one end of resistor R4. The other end of the secondary winding of transformer T1 is connected to the cathode of diode D2. The anode of diode D2 is connected to one end of capacitor C5 and the charging / discharging module. The tap of the secondary winding of transformer T1, the other end of capacitor C4, and the other end of capacitor C5 are all grounded.

[0022] In one embodiment, the switching 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 resistor R9 is connected to the push-pull module. The other end of resistor R9 is connected to one end of capacitor C8, one end of capacitor C9, and the gate of MOSFET Q6. The other end of capacitor C8 is connected to the drain of MOSFET Q6 and one end of capacitor C10. The other end of capacitor C9 is connected to the source of MOSFET Q6 and the other end of capacitor C10. The drain of MOSFET Q6 is connected to one end of inductor L3. The source of MOSFET Q6 is connected to one end of inductor L4. The other ends of inductor L3 and inductor L4 are connected to the switching application circuit to control the on / off state of the switching application circuit.

[0024] Furthermore, to achieve the above objectives, this application also proposes a power switching device driving method, which can be used in the power switching device driving circuit described above. The power switching device driving method includes:

[0025] The control module outputs control signals.

[0026] The drive signal is output through the driver chip module;

[0027] The power supply module generates a power supply voltage based on the control signal.

[0028] The amplitude of the power supply voltage is adjusted by the charging and discharging module, and a variable power supply voltage is output.

[0029] The push-pull module generates a variable drive signal based on the drive signal and the variable power supply voltage.

[0030] The switching module drives the power switching device to perform switching actions according to the variable drive signal.

[0031] In one embodiment, the step of adjusting the amplitude of the supply voltage by charging and discharging using a charging and discharging module to output a variable supply voltage includes:

[0032] The control module receives the turn-on control command and controls the field-effect transistor Q3 in the charging and discharging module to turn on according to the turn-on control command;

[0033] When the power switching device begins to enter the turn-on process, the control MOSFET Q3 is turned off.

[0034] When the gate-source voltage of the power switching device is greater than the preset turn-on voltage and close to the Miller plateau voltage, the control field-effect transistor Q3 is turned on.

[0035] When the power switching device begins to enter the current and voltage oscillation process, the control MOSFET Q3 is turned off so that the variable drive signal received by the switching module is stabilized within the first preset voltage range, and the power switching device is turned on.

[0036] In one embodiment, the step of adjusting the amplitude of the supply voltage by charging and discharging using the charging and discharging module to output a variable supply voltage further includes:

[0037] The control module receives a shutdown control command and controls the field-effect transistor Q3 in the charging and discharging module to turn on according to the shutdown control command.

[0038] When the power switching device begins to enter the turn-off process, the control MOSFET Q3 is turned off.

[0039] When the gate-source voltage of the power switching device approaches the Miller plateau voltage, the control MOSFET Q3 turns on.

[0040] When the power switching device begins to enter the current and voltage oscillation process, the control MOSFET Q3 is turned off so that the variable drive signal received by the switching module is stabilized within the second preset voltage range, and the power switching device is turned off.

[0041] One or more technical solutions proposed in this application have at least the following technical effects:

[0042] This application provides a power switching device driving circuit and method. The power switching device driving circuit includes a driving chip module for generating a driving signal; a driving power supply module for generating a supply voltage; a charging and discharging module connected to the driving power supply module, which can adjust the amplitude of the supply voltage through charging and discharging to output a variable supply voltage; a push-pull module connected to both the driving chip module and the charging and discharging module, which generates a variable driving signal based on the driving signal and the variable supply voltage; a switching module connected to the push-pull module, which includes a power switching device and is used to drive the power switching device to perform a switching action based on the variable driving signal; and a control module connected to the driving power supply module, the charging and discharging module, and the push-pull module through the driving chip module, which outputs a control signal to control the operation of the driving power supply module, the charging and discharging module, and the push-pull module.

[0043] In the power switching device drive circuit of this application, the charging and discharging module can adjust the amplitude of the supply voltage by charging and discharging to generate a variable supply voltage. This variable supply voltage can be combined with the drive signal and processed by the push-pull module to generate a variable drive signal, which is used to drive the power switching device in the switching module to perform switching actions. Compared with the circuits in related technologies that use n sets of switches and resistors to control the gate resistance value of the drive circuit at each stage of the switching process, thereby controlling the switching process, the drive circuit provided in this application can dynamically adjust the amplitude of the drive signal by charging and discharging, so that the performance of the power switching device can always be within an acceptable and optimal range during the switching process. The overall circuit structure is simplified, which facilitates the miniaturization of the product. Attached Figure Description

[0044] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0045] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of the structure of the power switching device drive circuit according to Embodiment 1 of this application;

[0047] Figure 2 This is a schematic diagram of the structure of the power switching device drive circuit according to Embodiment 2 of this application;

[0048] Figure 3 This is a detailed circuit schematic of the power switching device drive circuit of this application;

[0049] Figure 4 This is a flowchart illustrating an embodiment of the power switching device driving method of this application.

[0050] Figure 5 A schematic diagram of the switching trajectory of the power switching device in CGD drive mode;

[0051] Figure 6 This is a schematic diagram of the voltage control for the charging and discharging module.

[0052] Figure 7 This is a measured waveform diagram of the SiC MOSFET control process.

[0053] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0054] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0055] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0056] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0057] In the field of new energy vehicles, power switching devices are commonly used in automotive electronic control products. The driving method for these devices is primarily CGD (Conventional Gate Driver). However, the switching speed of power switching devices is difficult to guarantee under CGD driving. Therefore, the more advanced AGD (Active Gate Driver) method was developed. AGD can dynamically adjust the speed of power switching devices in various operating regions, ensuring it remains at its optimal value within the acceptable range for both the device and the system, thus achieving a balance between efficiency improvement, device safety, and EMI control.

[0058] In related technologies, AGD typically employs circuits composed of n sets of switches and resistors to control the gate resistance value of the drive circuit at each stage of the switching process. This allows for the control of the rate of change of current and voltage during different transient stages of the switching process, thereby achieving coordinated regulation of multiple characteristic quantities of the power switching device during the switching process. However, the aforementioned circuitry results in a large number of switches and resistors added to the entire drive system, leading to a complex structure that is not conducive to product miniaturization.

[0059] To address this technical problem, this application proposes a power switching device driving circuit. This circuit uses a charging and discharging module to adjust the amplitude of the power supply voltage of the driving chip through charging and discharging, generating a variable power supply voltage. This variable power supply voltage, combined with the driving signal output by the driving chip, is processed by a push-pull module to generate a variable driving signal, which is then used to drive the power switching device in the switching module to perform switching actions. Compared to related technologies that use circuits composed of n sets of switches and resistors to control the gate resistance value of the driving loop at each stage of the switching process, thereby controlling the switching process, the driving circuit provided in this application can dynamically adjust the amplitude of the driving signal through charging and discharging. This ensures that the performance of the power switching device remains within an acceptable and optimal range throughout the switching process. The overall circuit structure is simplified, facilitating product miniaturization.

[0060] The following will be explained and described through several embodiments.

[0061] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a power switching device drive circuit according to an embodiment of this application.

[0062] In this embodiment, the power switching device drive circuit includes:

[0063] The driver chip module is used to generate drive signals;

[0064] The driver power supply module is used to generate the power supply voltage;

[0065] A charging and discharging module, connected to the drive power module, is used to adjust the amplitude of the power supply voltage through charging and discharging, and output a variable power supply voltage.

[0066] The push-pull module is connected to the driver chip module and the charging / discharging module respectively, and is used to generate a variable drive signal based on the drive signal and the variable power supply voltage.

[0067] A switching module, connected to a push-pull module, includes power switching devices and is used to drive the power switching devices to perform switching actions according to a variable drive signal.

[0068] The control module is connected to the drive power module, charge / discharge module, and push-pull module respectively through the drive chip module. It is used to output control signals to control the operation of the drive power module, charge / discharge module, and push-pull module.

[0069] Specifically, the driver chip module can generate and output drive signals, and can integrate multiple driver chips; the drive power supply module can generate a stable supply voltage based on the control signals from the control module, providing drive voltage to the driver chips. The control module can be a control chip such as an FPGA (Field-Programmable Gate Array). The drive power supply module can be a switching power supply, ensuring a stable supply voltage output. Alternatively, as a feasible implementation method, refer to... Figure 2 , Figure 2 A detailed structural schematic diagram of a power switching device drive circuit according to Embodiment 1 is shown. In this embodiment, the drive power supply module may include an open-loop push-pull unit and a transformer unit;

[0070] An open-loop push-pull unit can be used to generate AC inverter signals;

[0071] 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 / discharge module. The transformer unit is used to generate the power supply voltage based on the AC inverter signal.

[0072] The open-loop push-pull unit receives control signals from the control module via the driver chip IC2 of the driver chip module and generates AC inverter signals 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 / discharge module. Thus, the transformer unit can generate a corresponding supply voltage on the secondary side based on the AC inverter signal input from the primary side. This supply voltage can be further processed by the charge / discharge module connected to the transformer unit.

[0073] In one feasible implementation, refer to Figure 3 , Figure 3 A detailed circuit schematic of the power switching device drive circuit of this application is shown. (See attached diagram.) Figure 3As shown, the open-loop push-pull unit may include field-effect transistor Q1, field-effect transistor Q2, resistors R1, R2, R3, and R4, and capacitors C1, C2, and C3.

[0074] The drain of MOSFET Q1 is connected to one end of resistor R2, one end of resistor R3, and the primary side of the transformer unit. The gate of MOSFET Q1 is connected to the control module. The drain of MOSFET Q2 is connected to one end of resistor R1, one end of resistor R4, and the primary side of the transformer unit. The gate of MOSFET Q2 is connected to the control module. The other end of resistor R3 is connected to the other end of resistor R4. The common junction of resistors R3 and R4 is connected to the primary side of the transformer unit, one end of capacitor C3, and the 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 sources of MOSFETs Q1 and Q2 are both grounded.

[0075] The transformer unit may include transformer T1, diode D1, diode D2, capacitor C4, and capacitor C5;

[0076] The tap of the primary winding of transformer T1 is connected to the other end of resistor R3. One end of the primary winding of transformer T1 is connected to one end of resistor R3. One end of the secondary winding of transformer T1 is connected to the anode of diode D1. The cathode of diode D1 is connected to one end of capacitor C4 and the charging / discharging module. The other end of the primary winding of transformer T1 is connected to one end of resistor R4. The other end of the secondary winding of transformer T1 is connected to the cathode of diode D2. The anode of diode D2 is connected to one end of capacitor C5 and the charging / discharging module. The tap of the secondary winding of transformer T1, the other end of capacitor C4, and the other end of capacitor C5 are all grounded.

[0077] Specifically, in the open-loop push-pull unit, the gates of both field-effect transistors Q1 and Q2 can be connected to the control module, and the control module can output control signals for the gates of the field-effect transistors. Figure 3 The GATE_Q1 and GATE_Q2 in the transformer T1 control the alternating conduction of MOSFETs Q1 and Q2. For example, when MOSFET Q1 is on, MOSFET Q2 is off. The external power supply V1 can be transformed through the windings on the primary and secondary sides of transformer T1 to obtain a stable output voltage (i.e., the supply voltage). The amplitude of the output voltage can be calculated by the following formula: In the formula, V out V is the output voltage value on the secondary side of transformer T1. in The input voltage value on the primary side of transformer T1 ( Figure 3 V1), V MV represents the on-state voltage drop of the field-effect transistors (Q1, Q2) in the open-loop push-pull unit connected to the primary side of transformer T1. D N represents the forward voltage drop of the diodes (D1, D2) on the secondary side of transformer T1. s N represents the number of turns in the secondary winding of transformer T1. P T represents the number of turns in the primary winding of transformer T1. ON Let T be the conduction time of the MOSFET in the push-pull unit, and T be the period of alternating conduction of the MOSFET. From the above formula, it can be seen that, given a fixed input voltage and the selected components in the open-loop push-pull unit and transformer unit, the amplitude of the output voltage (i.e., the supply voltage) on the secondary side of the transformer can be adjusted by the duty cycle of the MOSFET. In this embodiment, the positive output voltage of the drive signal can be adjusted to +17V, and the negative output voltage of the drive signal can be adjusted to -4.5V. Furthermore, in the above circuit structure, capacitors C4 and C5 are voltage-stabilizing capacitors, which can stabilize the output voltage of transformer T1 to ensure the stability of the supply voltage.

[0078] After obtaining the supply voltage using the drive power module, a charge / discharge module connected to the drive power module can be used to perform charge / discharge processing based on the supply voltage, thereby adjusting the amplitude of the supply voltage and obtaining a variable supply voltage. The variable supply voltage and the drive signal output from the drive chip module are then processed by the push-pull module to obtain a variable drive signal. This variable drive signal can be used to drive the power switching devices in the aforementioned switching module to perform switching actions.

[0079] In one feasible implementation, such as Figure 3 As shown, the charging and discharging module may include inductor L1, inductor L2, diode D3, diode D4, field-effect transistor Q3, capacitor C6, capacitor C7 and resistor R5;

[0080] One end of inductor L1 is connected to the drive power module, and the other end of inductor L1 is connected to the anode of diode D3. The cathode of diode D3 is 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, and the other end of inductor L2 is connected to the cathode of diode D4. The anode of diode D4 is 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. The other ends of capacitors C6 and C7 are grounded.

[0081] Specifically, the driver chip module may include an isolation driver chip IC1, and the control signals output by the control module (such as...) Figure 3The AGD_1 signal shown can be input to the gate of the field-effect transistor Q3 through the isolation driver chip IC1 to control the conduction or cutoff of Q3. When Q3 is on, inductors L1 and L2, together with diodes D3 and D4, form a charging circuit, storing electrical energy. When Q3 is off, the stored energy in inductors L1 and L2 is released. During charging and discharging, the supply voltage can change in real time as the charging and discharging process progresses, thus obtaining a variable supply voltage. Capacitors C6 and C7 can filter out some signal noise interference, maintain circuit stability, and in some cases, can also be used to temporarily store or release electrical energy. Resistor R5 is a current-limiting resistor, which can prevent sudden changes in circuit current during charging, thus preventing the circuit from affecting stability or damaging other components. The driver chip module may also include an isolation driver chip IC3, which is the driver chip for the power switching device in the switching module. The control module can output an initial drive signal, which, after passing through the isolation driver chip IC3, can output a drive signal to the push-pull module. The push-pull module can generate a variable drive signal based on the variable supply voltage output by the charging and discharging module and the drive signal output by the driver chip, so as to drive the power switching device of the switching module to perform switching actions.

[0082] In one feasible implementation, such as Figure 3 As shown, the push-pull module may include resistors R6, R7, and R8, MOSFET Q4, and MOSFET Q5;

[0083] One end of resistor R6 and one end of resistor R7 are both connected to the control module through the driver chip module. The other end of resistor R6 is connected to the gate of field-effect transistor Q4. The source of field-effect transistor Q4 is connected to the charging and discharging module. The other end of resistor R7 is connected to the gate of field-effect transistor Q5. The source of field-effect transistor Q5 is connected to the charging and discharging module. The drains of field-effect transistors Q4 and Q5 are both connected to one end of resistor R8. The other end of resistor R8 is connected to the switching module.

[0084] Specifically, the gates of field-effect transistors Q4 and Q5 are connected to the isolation driver chip IC3 in the aforementioned driver chip module via resistors R6 and R7, respectively. IC3 is then connected to the control module, which can output an initial drive signal. After passing through IC3, the control module can output a drive signal (such as...). Figure 3The PWM_Vgs_1 parameter controls the on / off state of MOSFETs Q4 and Q5. When MOSFET Q4 is on, MOSFET Q5 is off. The positive voltage (forward supply voltage) from the charge / discharge module can then be input to the gate of the power switch, turning it on. When MOSFET Q4 is off, MOSFET Q5 is on. The negative voltage (negative supply voltage) from the charge / discharge module can then be input to the gate of the power switch, turning it off. MOSFET Q4 can be a P-channel enhancement-mode MOSFET, and MOSFET Q5 can be an N-channel enhancement-mode MOSFET. It should be noted that... Figure 3 V2 and V3 are the output points of the power supply module. The isolation driver chip IC3 can draw power from V2 and V3. V4 and V5 are the output points of the charge and discharge module. The push-pull module can draw power from V4 and V5.

[0085] In addition, such as Figure 3 As shown, the switching module may include resistor R9, capacitor C8, capacitor C9, capacitor C10, inductor L3, inductor L4 and field-effect transistor Q6;

[0086] One end of resistor R9 is connected to the push-pull module. The other end of resistor R9 is connected to one end of capacitor C8, one end of capacitor C9, and the gate of MOSFET Q6. The other end of capacitor C8 is connected to the drain of MOSFET Q6 and one end of capacitor C10. The other end of capacitor C9 is connected to the source of MOSFET Q6 and the other end of capacitor C10. The drain of MOSFET Q6 is connected to one end of inductor L3. The source of MOSFET Q6 is connected to one end of inductor L4. The other ends of inductor L3 and inductor L4 are connected to the switching application circuit to control the on / off state of the switching application circuit.

[0087] The resistors R9, capacitors C8, C9, and C10, inductors L3 and L4, and the MOSFET Q6 can constitute an equivalent model of a power switching device. During the turn-on and turn-off processes of a power switching device (such as a silicon carbide MOSFET), the characteristics of the power switching device are mainly adjusted by regulating the charging speed of the gate of the power switching device on the input capacitor Ciss, output capacitor Coss, and inverting transfer capacitor Crss. Where Ciss = C8 + C9, Coss = C8 + C10, and Crss = C8; the formulas for capacitor charging voltage versus time are shown below: In the formula, V tLet Vt be the voltage value at time t, V0 be the capacitor charging power supply voltage (i.e., the gate drive voltage of the power switching device), R be the gate drive resistance (i.e., the resistance of resistors R8 + R9), C be the junction capacitance of the power switching device (Ciss, Coss, and Crss), and t be the charging time. Given a fixed gate drive resistance and junction capacitance of the power switching device, adjusting the amplitude of the gate drive voltage (i.e., the drive signal) can directly control the rate of change of voltage and current in different operating regions during the turn-on process of the power switching device, achieving a balance between losses, current overshoot, and oscillations during turn-on. Similarly, adjusting the amplitude of the gate drive voltage (i.e., the drive signal) can also achieve a balance between losses, overshoot, and oscillations during the turn-off process of the power switching device.

[0088] Therefore, the power switching device driving circuit provided in this embodiment can adjust the amplitude of the supply voltage through a charging and discharging module to generate a variable supply voltage. This variable supply voltage, combined with the driving signal and processed by the push-pull module, generates a variable driving signal to drive the power switching device in the switching module to perform switching actions. This eliminates the need for separate circuits consisting of n sets of switches and resistors to control the gate resistance value of the driving loop at each stage of the switching process to achieve switching control of the power switching device. The power switching device driving circuit provided in this embodiment dynamically adjusts the amplitude of the driving signal through charging and discharging, ensuring that the performance of the power switching device remains within an acceptable and optimal range during the switching process. The overall circuit structure is simplified, facilitating product miniaturization.

[0089] Furthermore, embodiments of this application provide a power switching device driving method, which can be used in the power switching device driving circuit described above, with reference to... Figure 4 , Figure 4 A flowchart illustrating an embodiment of the power switching device driving method of this application is shown.

[0090] In this embodiment, the power switching device driving method includes steps S100 to S600:

[0091] In step S100, a control signal is output through the control module.

[0092] In step S200, a drive signal is output through the driver chip module.

[0093] In step S300, the power supply module generates a power supply voltage according to the control signal.

[0094] In step S400, the amplitude of the power supply voltage is adjusted by the charging and discharging module to output a variable power supply voltage.

[0095] In step S500, a variable drive signal is generated by the push-pull module based on the drive signal and the variable power supply voltage.

[0096] In step S600, the power switching device is driven by the switching module to perform a switching action according to the variable drive signal.

[0097] Specifically, the control module can output control signals to the drive power module, enabling the drive power module to generate a stable supply voltage. Detailed implementation information can be found in the power switching device drive circuit embodiment section, and will not be repeated here. Then, using the charging and discharging module connected to the drive power module, the amplitude of the supply voltage can be adjusted by charging and discharging, resulting in a variable supply voltage. This variable supply voltage, along with the drive signal output from the drive chip module, is processed by the push-pull module to obtain a variable drive signal, which is used to drive the power switching device to perform switching operations.

[0098] In one feasible implementation, step S400 may specifically include steps S410 to S440 to optimize the performance of the power switching device during the turn-on process.

[0099] Step S410: Receive the conduction control command through the control module, and control the field-effect transistor Q3 in the charging and discharging module to conduct according to the conduction control command.

[0100] In step S420, when the power switching device begins to enter the turn-on process, the control MOSFET Q3 is turned off.

[0101] Step S430: When the gate-source voltage of the power switching device is greater than the preset turn-on voltage and close to the Miller plateau voltage, the field-effect transistor Q3 is turned on.

[0102] In step S440, when the power switching device begins to enter the current-voltage oscillation process, the control field-effect transistor Q3 is turned off so that the variable drive signal received by the switching module is stabilized within the first preset voltage range, and the power switching device is turned on.

[0103] In another feasible implementation, step S400 may further include steps S450 to S480 to optimize the performance of the power switching device during the turn-off process.

[0104] In step S450, the control module receives a shutdown control command and controls the field-effect transistor Q3 in the charging and discharging module to turn on according to the shutdown control command.

[0105] Step S460: When the power switching device begins to enter the turn-off process, the control MOSFET Q3 is turned off.

[0106] In step S470, when the gate-source voltage of the power switching device approaches the Miller plateau voltage, the control field-effect transistor Q3 is turned on.

[0107] In step S480, when the power switching device begins to enter the current-voltage oscillation process, the control field-effect transistor Q3 is turned off so that the variable drive signal received by the switching module is stabilized within the second preset voltage range, and the power switching device is turned off.

[0108] Understandably, while faster switching speeds in power switching devices reduce switching losses, the higher rates of voltage and current change cause voltage and current overshoot, which can negatively impact the stability of the power switching devices. In CGD drive mode, the switching trajectory of the power switching device is as follows: Figure 5 As shown, Figure 5 In the middle, V EE The output negative voltage (negative supply voltage) of the drive signal, V CC To drive the signal, output a positive voltage (forward supply voltage), V th V is the turn-on threshold (i.e., the preset turn-on voltage) of the power switching device. mp This represents the Miller plateau voltage value. Region I (t0-t1) and Region V (t5-t6) represent the turn-on and turn-off delay processes of the power switching device, respectively. Figure 5 It can be seen that the voltage and current of the power switching device do not change significantly in regions I and V, but the duration of these two regions directly affects the switching speed and dead time setting of the power switching device; therefore, the shorter the duration of these regions, the better. Regions III (t2-t3) and VII (t7-t8) are the current overshoot regions during the turn-on process and the voltage overshoot regions during the turn-off process, respectively. The voltage and current amplitudes of these overshoots are determined by the parasitic parameters of the power circuit and... and A joint decision, in which, Drain-source current i ds The rate of change with time t Drain-source voltage v ds The rate of change with time t must be strictly controlled within the device's safe operating area. Regions IV and VIII are oscillation regions for current and voltage. When the parasitic parameters of the power circuit are determined, the magnitude of their oscillation amplitude is determined by the parameters of region III. and Zone VII Each region has its own control mechanism, and the oscillation amplitude must be strictly controlled within the system's EMI and device tolerance ranges. Regions II and VI are the linear rise regions of current and voltage, respectively, and are key control regions for decoupling switching time, switching losses, and current / voltage overshoot and oscillation. The quality of control determines the specific effects of reducing switching losses, current / voltage overshoot and oscillation, and reducing EMI (electromagnetic interference) and phase-to-phase crosstalk. From the above analysis, it is clear that the switching speeds in regions II, III, VI, and VII directly determine the turn-on and turn-off losses of power devices. From a loss perspective, the shorter the time in these four regions, the lower the switching losses of the power devices, which is more conducive to improving system efficiency. However, from the perspective of device tolerance and system EMI, the longer the time in these four regions, the lower the current and voltage stress on the power devices, which is more conducive to device safety and system EMI control. Therefore, dynamic adjustment of these regions is necessary to achieve the optimal performance of the power switching devices.

[0109] Specifically, the control module can receive external control commands for the power switching devices. Based on these commands, the control module can control the MOSFET Q3 in the charging module to turn on. That is, before the switching trajectory enters region I, the MOSFET Q3 is turned on to form a charging circuit. The inductor in the circuit stores energy. At this time, the supply voltage can drop from 21.5V to 15V. This drop in supply voltage causes the gate-source voltage v of the switching power device to decrease. gs The amplitude increases from -4.5V to -3V; when the power switching device begins to enter the switching process, that is, v gs When entering region I (t0-t1), the field-effect transistor Q3 can be turned off. At this time, the circuit formed by the field-effect transistor Q3 is broken, the inductor energy is released, and the supply voltage rises from 15V to 23V. The increase in supply voltage causes v gs The reference voltage amplitude increases from +12V to +18V, thereby shortening the time of the power switching device in regions I and II. When the gate-source voltage of the power switching device is greater than the preset turn-on voltage and close to the Miller plateau voltage, the MOSFET Q3 can be turned on. At this time, the inductor stores energy again, the supply voltage drops again, and it is in the Miller plateau voltage range. gs The amplitude rises more slowly due to the decrease in the supply voltage amplitude, thus prolonging the time the power switching device spends in region III (t2-t3), and increasing the drain-source current i. ds The overshoot amplitude in region III (t2-t3) and the oscillation amplitude in region IV are both reduced. When the power switching device begins to enter the current-voltage oscillation process (entering region IV), the MOSFET Q3 can be turned off again to stabilize the amplitude of the variable drive signal received by the switching module within the first preset voltage range. After the MOSFET Q3 is turned off, the inductor's stored energy is released again, causing v... gs The amplitude rises again and eventually stabilizes at +17V, completing the conduction process of the power switching device.

[0110] like Figure 6 As shown, Figure 6 A schematic diagram illustrating the voltage adjustment process for the charging and discharging module. Figure 6 The load loop control PWM in the circuit is the AGD_1 signal applied to the MOSFET Q3. Similarly, the control module can receive external shutdown control commands for the power switching devices. Based on these commands, the control module can control the MOSFET Q3 in the charging module to turn on, that is, before the switching trajectory enters region V, it controls MOSFET Q3 to turn on, forming a charging loop. The inductor in the loop stores energy, and the supply voltage can drop from 21.5V to 15V. This drop in supply voltage causes the gate-source voltage v of the switching power device to decrease. gs The amplitude drops from +17V to +12V; when the power switching device begins to enter the turn-off process, that is, v gs Upon entering region V (t5-t6), MOSFET Q3 can be turned off. At this time, the circuit formed by MOSFET Q3 is broken, the inductor energy is released, and the supply voltage rises from 15V to 23V. This voltage increase causes the Vgs reference voltage amplitude to drop from -3V to -5V, thus shortening the time the power switching device spends in regions V and VI. When the gate-source voltage of the power switching device approaches the Miller plateau voltage, MOSFET Q3 can be turned on. At this time, the inductor stores energy again, and the supply voltage drops again. gs The rate of decrease in amplitude slows down due to the decrease in the supply voltage amplitude, thus prolonging the time that the power switching devices spend in region VII (t7-t8). ds The amplitudes of overshoot in region VII and oscillation in region VIII both decrease. When the power switching device begins to enter the current-voltage oscillation process (entering region VIII), the MOSFET Q3 can be turned off again to stabilize the amplitude of the variable drive signal received by the switching module within the second preset voltage range. After the MOSFET Q3 is turned off, the inductor's stored energy is released again, causing v... gs The amplitude decreases and eventually stabilizes at -4.5V, completing the conduction process of the power switching device.

[0111] Understandably, in the power switching device driving method provided in this embodiment, a control module can output a control signal, a drive power supply module can generate a supply voltage according to the control signal, a charge and discharge module can adjust the amplitude of the supply voltage by charging and discharging to output a variable supply voltage, and 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. Thus, the power switching device can be driven to perform switching actions by the switch module according to the variable drive signal. The control and implementation scheme of the circuit is relatively simple, which facilitates the miniaturization design of the drive circuit product.

[0112] Furthermore, to verify the effectiveness of the power switching device driving method in this embodiment, taking SiCMOSFET as an example, various signal waveforms were measured in real time during the control process, such as... Figure 7 As 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 supply voltage drops due to the conduction of the field-effect transistor Q3 circuit, causing v... gs The reference voltage rises from -4.5V to approximately -3V; when the SiC MOSFET enters region I, the circuit of the field-effect transistor Q3 is disconnected, causing the reference voltage Vgs to rise to approximately +18V; when the SiC MOSFET enters region III, the circuit of the field-effect transistor Q3 is turned on again, and Vgs... gs Lowering the reference voltage will slow down i ds The rise rate of the SiC MOSFET is increased, extending the time the SiC MOSFET spends in region III; when the SiC MOSFET is in region IV, the Q3 circuit of the field-effect transistor is disconnected again, causing v gs The reference voltage rose and eventually stabilized at +17V, consistent with the theoretical situation.

[0113] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A power switching device drive circuit, characterized in that, The power switching device drive circuit includes: The driver chip module is used to generate drive signals; The driver power supply module is used to generate the power supply voltage; A charging and discharging module, connected to the driving power module, is used to adjust the amplitude of the power supply voltage through charging and discharging, and output a variable power supply voltage. The push-pull module is connected to the driver chip module and the charging / discharging module respectively, and is used to generate a variable drive signal according to the drive signal and the variable power supply voltage; A switching module is connected to the push-pull module. The switching module includes a power switching device and is used to drive the power switching device to perform a switching action according to the variable drive signal. The control module is connected to the drive power module, the charge / discharge module and the push-pull module respectively through the drive chip module, and is used to output control signals to control the operation of the drive power module, the charge / discharge module and the push-pull module.

2. The power switching device drive circuit as described in claim 1, characterized in that, The charging and discharging module includes inductor L1, inductor L2, diode D3, diode D4, field-effect transistor Q3, capacitor C6, capacitor C7, and resistor R5; One end of inductor L1 is connected to the driving power module, and the other end of inductor L1 is connected to the anode of diode D3. The cathode of diode D3 is 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 driving power module, and the other end of inductor L2 is connected to the cathode of diode D4. The anode of diode D4 is 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 driving chip module. The other ends of capacitor C6 and capacitor C7 are grounded.

3. The power switching device drive circuit as described in claim 1, characterized in that, The push-pull module includes resistors R6, R7, and R8, as well as field-effect transistors Q4 and Q5. One end of resistor R6 and one end of resistor R7 are both connected to the control module through the driver chip module. The other end of resistor R6 is connected to the gate of field-effect transistor Q4. The source of field-effect transistor Q4 is connected to the charge-discharge module. The other end of resistor R7 is connected to the gate of field-effect transistor Q5. The source of field-effect transistor Q5 is connected to the charge-discharge module. The drains of field-effect transistors Q4 and Q5 are both connected to one end of resistor R8. The other end of resistor R8 is connected to the switch module.

4. The power switching device drive circuit as described in claim 1, characterized in that, The drive power module includes an open-loop push-pull unit and a transformer unit; The open-loop push-pull unit is used to generate AC inverter signals; 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 charging and discharging module. The transformer unit is used to generate the power supply voltage according to the AC inverter signal.

5. The power switching device drive circuit as described in 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 transistor Q1 is 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 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 junction of the resistors R3 and R4 is 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. The sources of both the field-effect transistor Q1 and the field-effect transistor Q2 are grounded.

6. The power switching device drive circuit as described in claim 5, characterized in that, The transformer unit includes a transformer T1, a diode D1, a diode D2, a capacitor C4, and a capacitor C5; The tap of the primary winding of transformer T1 is connected to the other end of resistor R3. One end of the primary winding of transformer T1 is connected to one end of resistor R3. One end of the secondary winding of transformer T1 is connected to the anode of diode D1. The cathode of diode D1 is connected to one end of capacitor C4 and the charging / discharging module. The other end of the primary winding of transformer T1 is connected to one end of resistor R4. The other end of the secondary winding of transformer T1 is connected to the cathode of diode D2. The anode of diode D2 is connected to one end of capacitor C5 and the charging / discharging module. The tap of the secondary winding of transformer T1, the other end of capacitor C4, and the other end of capacitor C5 are all grounded.

7. The power switching device drive circuit as described in claim 1, characterized in that, The switching module includes resistor R9, capacitor C8, capacitor C9, capacitor C10, inductor L3, inductor L4 and field-effect transistor Q6; One end of resistor R9 is connected to the push-pull module. The other end of resistor R9 is 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 connected to the drain of field-effect transistor Q6 and one end of capacitor C10. The other end of capacitor C9 is 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 a switching application circuit to control the on / off state of the switching application circuit.

8. A method for driving a power switching device, characterized in that, For a power switching device driving circuit as described in any one of claims 1 to 7, the power switching device driving method includes: The control module outputs control signals. The drive signal is output through the driver chip module; The power supply module generates a power supply voltage according to the control signal; The amplitude of the power supply voltage is adjusted by the charging and discharging module to output a variable power supply voltage. The push-pull module generates a variable drive signal based on the drive signal and the variable power supply voltage. The switching module drives the power switching device to perform switching actions according to the variable drive signal.

9. The power switching device driving method as described in claim 8, characterized in that, The step of adjusting the amplitude of the supply voltage through the charging and discharging module to output a variable supply voltage includes: The control module receives a turn-on control command and controls the field-effect transistor Q3 in the charging and discharging module to turn on according to the turn-on control command; When the power switching device begins to enter the turn-on process, the field-effect transistor Q3 is turned off. When the gate-source voltage of the power switching device is greater than the preset turn-on voltage and close to the Miller plateau voltage, the field-effect transistor Q3 is turned on. When the power switching device begins to enter the current and voltage oscillation process, the field-effect transistor Q3 is controlled to turn off, so that the variable drive signal received by the switching module is stabilized within the first preset voltage range, and the power switching device is turned on.

10. The power switching device driving method as described in claim 9, characterized in that, The step of adjusting the amplitude of the power supply voltage by using the charging and discharging module to output a variable power supply voltage further includes: The control module receives a shutdown control command and controls the field-effect transistor Q3 in the charging and discharging module to turn on according to the shutdown control command. When the power switching device begins to enter the turn-off process, the field-effect transistor Q3 is turned off. When the gate-source voltage of the power switching device approaches the Miller plateau voltage, the field-effect transistor Q3 is turned on. When the power switching device begins to enter the current and voltage oscillation process, the field-effect transistor Q3 is controlled to turn off, so that the variable drive signal received by the switching module is stabilized within the second preset voltage range, and the power switching device is turned off.

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