SiC-IGBT hybrid power module separation drive circuit

Abstract

The utility model relates to the technical field of driving circuits, in particular to a SiC-IGBT hybrid power module separation driving circuit, which comprises an MCU (Microprogrammed Control Unit), a SiC driving chip, an IGBT driving chip and a half-bridge circuit, the signal input end of the SiC driving chip is used for receiving a SiCPWM control signal sent by the MCU, and the driving signal output end of the SiC driving chip is connected with the signal input end A of the half-bridge circuit; the signal input end of the IGBT driving chip is used for receiving an IGBT PWM control signal sent by the MCU, and the driving signal output end of the IGBT driving chip is connected with the signal input end B of the half-bridge circuit; the power signal input end C of the half-bridge circuit is connected with a bus DC +, and the power signal input end D of the half-bridge circuit is connected with a bus DC-. According to the utility model, each path of driving power supply of the hybrid power module separation driving circuit can be allocated according to requirements, the switching sequence can be changed through an instruction sent by the MCU, and the switching delay time can be adjusted according to the instruction of the MCU.

Description

Technical Field

[0001] This utility model relates to the field of drive circuit technology, specifically a separate drive circuit for a SiC-IGBT hybrid power module. Background Technology

[0002] With the development of new energy vehicle technology, the requirements for the power level and efficiency of motor controllers are becoming increasingly higher. Traditional Si-based IGBT modules have limited output capabilities, high losses, low efficiency, and the switching frequency should not be too high. Therefore, SiC power modules have been extensively researched and used. SiC power modules can greatly improve the power level, reduce losses, and improve system efficiency, thereby increasing the driving range. However, SiC power modules are very expensive and in short supply. In order to solve the above problems, hybrid power modules combining SiC transistors and IGBT transistors have been gradually developed. The overall performance of hybrid modules is between that of IGBTs and SiC.

[0003] Existing adaptive hybrid power module drive circuits, such as Figure 1 As shown, Si-based IGBTs and SiC transistors use the same drive path, the drive power supply is not adjustable, and the switching sequence and switching delay are not adjustable, which cannot fully utilize the advantages of hybrid modules.

[0004] Therefore, in order to better utilize the optimal performance of each hybrid power module, a dedicated drive circuit needs to be developed to match them. The dedicated drive circuit should have the following requirements: (1) the drive power supply voltage of SiC and IGBT is adjustable; (2) the switching sequence of SiC and IGBT is adjustable; and (3) the switching delay time of SiC and IGBT is adjustable. In view of the above requirements, this utility model provides a separate drive circuit for SiC-IGBT hybrid power modules. Utility Model Content

[0005] The purpose of this invention is to provide a separate drive circuit for a SiC-IGBT hybrid power module to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A SiC-IGBT hybrid power module discrete drive circuit includes: an MCU, a SiC driver chip, an IGBT driver chip, and a half-bridge circuit;

[0008] The signal input terminal of the SiC driver chip is used to receive the SiC_PWM control signal sent by the MCU, and the drive signal output terminal is connected to the signal input terminal A of the half-bridge circuit.

[0009] The signal input terminal of the IGBT driver chip is used to receive the IGBT_PWM control signal sent by the MCU, and the drive signal output terminal is connected to the signal input terminal B of the half-bridge circuit.

[0010] The power signal input terminal C of the half-bridge circuit is connected to the bus DC+, and the power signal input terminal D is connected to the bus DC-.

[0011] Preferably, the power signal input terminal of the SiC driver chip is powered through VCC_SiC; the negative voltage power supply terminal is powered through VEE_SiC.

[0012] Preferably, the power signal input terminal of the IGBT driver chip is powered through VCC_IGBT; the negative voltage power supply terminal is powered through VEE_IGBT.

[0013] Preferably, the half-bridge circuit includes: an upper-bridge SiC transistor, an upper-bridge IGBT transistor, a lower-bridge SiC transistor, a lower-bridge IGBT transistor, a resistor R2, a gate capacitor C1, a resistor R4, and a gate capacitor C2; wherein: the gate of the upper-bridge SiC transistor is connected to the signal input terminal A through a driving resistor R1; the base of the upper-bridge IGBT transistor is connected to the signal input terminal B through a driving resistor R3; the drain of the upper-bridge SiC transistor and the collector of the upper-bridge IGBT transistor are connected in series and then connected to the power signal input terminal C; the upper-bridge SiC transistor... The source of the upper-bridge IGBT transistor is connected in series with the emitter of the lower-bridge SiC transistor, and then connected to the drain and collector of the lower-bridge IGBT transistor. The source of the lower-bridge SiC transistor is connected in series with the emitter and collector of the lower-bridge IGBT transistor, and then connected to the power signal input terminal D. One end of the resistor R2 and the gate capacitor C1 connected in parallel is connected to the gate of the upper-bridge SiC transistor, and the other end is connected to the source of the upper-bridge SiC transistor. One end of the resistor R4 and the gate capacitor C2 connected in parallel is connected to the base of the upper-bridge IGBT transistor, and the other end is connected to the emitter of the upper-bridge IGBT transistor.

[0014] Compared with the prior art, the beneficial effects of this utility model are: the SiC-IGBT hybrid power module has a separate drive circuit, which drives the SiC transistor through the SiC driver chip and the IGBT transistor through the IGBT driver chip, so that the drive power supply of each channel can be adjusted according to the requirements, the switching sequence can also be changed by the instructions sent by the MCU, and the switching delay time can also be adjusted according to the instructions of the MCU. Attached Figure Description

[0015] Figure 1 A schematic diagram of the discrete drive circuit for a traditional hybrid power module in the prior art;

[0016] Figure 2This is a schematic diagram of the discrete drive circuit for the hybrid power module of this utility model;

[0017] Figure 3 This is an example of a PWM waveform diagram showing the switching sequence controlled by an MCU in this invention;

[0018] Figure 4 This is an example of a PWM waveform diagram showing the MCU controlling the switch delay time in this invention. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "set up" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0021] A discrete drive circuit for a SiC-IGBT hybrid power module, such as Figure 2As shown, the system includes: an MCU, a SiC driver chip, an IGBT driver chip, and a half-bridge circuit. The signal input terminal of the SiC driver chip receives the SiC_PWM control signal from the MCU, and its drive signal output terminal is connected to the signal input terminal A of the half-bridge circuit. The power signal input terminal of the SiC driver chip is powered through VCC_SiC, and its negative voltage power supply terminal is powered through VEE_SiC. The signal input terminal of the IGBT driver chip receives the IGBT_PWM control signal from the MCU, and its drive signal output terminal is connected to the signal input terminal B of the half-bridge circuit. The power signal input terminal of the IGBT driver chip is powered through VCC_IGBT, and its negative voltage power supply terminal is powered through VEE_IGBT. The power signal input terminal C of the half-bridge circuit is connected to the DC+ bus, and the power signal input terminal D is connected to the DC- bus. Specifically, the half-bridge circuit includes: an upper-bridge SiC transistor, an upper-bridge IGBT transistor, a lower-bridge SiC transistor, a lower-bridge IGBT transistor, a resistor R2, a gate capacitor C1, a resistor R4, and a gate capacitor C2; wherein: the gate of the upper-bridge SiC transistor is connected to the signal input terminal A through a driving resistor R1; the base of the upper-bridge IGBT transistor is connected to the signal input terminal B through a driving resistor R3; the drain of the upper-bridge SiC transistor and the collector of the upper-bridge IGBT transistor are connected in series to the power signal input terminal C; the upper-bridge SiC transistor... The source of the upper-bridge IGBT transistor is connected in series with the emitter of the lower-bridge SiC transistor, and then connected to the drain and collector of the lower-bridge IGBT transistor. The source of the lower-bridge SiC transistor is connected in series with the emitter and collector of the lower-bridge IGBT transistor, and then connected to the power signal input terminal D. One end of the resistor R2 and the gate capacitor C1 connected in parallel is connected to the gate of the upper-bridge SiC transistor, and the other end is connected to the source of the upper-bridge SiC transistor. One end of the resistor R4 and the gate capacitor C2 connected in parallel is connected to the base of the upper-bridge IGBT transistor, and the other end is connected to the emitter of the upper-bridge IGBT transistor.

[0022] This invention changes the traditional scheme of simultaneously driving SiC transistors and IGBT transistors with a single drive circuit to a scheme using two drive chips (SiC drive chip and IGBT drive chip). The SiC drive chip drives the SiC transistors, and the IGBT drive chip drives the IGBT transistors. This allows the drive power supply of each channel to be adjusted as needed, the switching sequence can be changed by instructions sent by the MCU, and the switching delay time can also be adjusted according to the MCU instructions.

[0023] Its working principle is as follows:

[0024] SiC transistor drive loop path:

[0025] The MCU sends a SiC_PWM drive signal. At this time, the 5V drive signal has no driving capability. This signal is sent to the SiC driver chip and amplified and enhanced by its internal push-pull circuit. The enhanced drive signal is the high level of VCC_SiC and the low level of VEE_SiC. This drive signal then passes through the drive resistor R1 and the gate capacitor C1 to enter the gate of the upper bridge SiC transistor and control its switching. Here, the drive resistor R1 and the gate capacitor C1 work together to control the switching speed of the upper bridge SiC transistor. Resistor 2 mainly performs pull-down.

[0026] IGBT transistor drive loop path:

[0027] The MCU sends an IGBT_PWM drive signal. At this time, the 5V drive signal has no driving capability. This signal is sent to the IGBT driver chip and amplified and enhanced by the internal push-pull circuit. The enhanced drive signal is the high level of VCC_IGBT and the low level of VEE_IGBT. This drive signal passes through the drive resistor R3 and the gate capacitor C2 to enter the base of the IGBT transistor and thus control its switching. Here, the drive resistor R3 and the gate capacitor C2 work together to control the switching speed of the IGBT transistor, and the resistor R4 mainly performs pull-down.

[0028] (1) Adjustment of drive power supply:

[0029] The power supplies VCC_SiC and VEE_SiC of the SiC driver chip are controllable, and the power supplies VCC_IGBT and VEE_IGBT of the IGBT driver chip are also controllable and can be adjusted according to actual needs.

[0030] (2) Control of the switching sequence:

[0031] In this embodiment, the switching sequence and switching delay time are changed by control commands sent by the MCU. The switching is based on the output phase current, and the switching current magnitude is set as X, and the threshold is set as Y. The magnitudes of X and Y need to be adjusted according to the actual situation, which will be explained in detail here:

[0032] For example:

[0033] Strategy A corresponds to Figure 3 SiC first-on, then-off logic;

[0034] Strategy B corresponds to Figure 3 The IGBT's turn-on-then-off logic in China;

[0035] The MCU controls power-on, completes self-test, and sends drive commands. Initially, it executes according to strategy A.

[0036] When the detected current is greater than X+Y, switch to strategy B;

[0037] Continue running

[0038] When the detected current is lower than XY, switch to strategy A;

[0039] Continue running.

[0040] This is based on the original text. Figure 3 Taking the SiC transistor's turn-on-then-off behavior as an example, when the SiC transistor needs to be turned on and off, the PWM_SiC control signal issued by the MCU's internal switching logic processing circuit will precede the PWM_IGBT signal when turning on and lag the PWM_IGBT signal when turning off. This achieves the SiC transistor's turn-on-then-off behavior based on the signal issued by the MCU. The PWM_SiC and PWM_IGBT signals are then driven by the SiC driver chip and IGBT driver chip respectively before being sent to the SiC and IGBT, thus realizing the SiC transistor's turn-on-then-off behavior in the hybrid power module. The turn-on-then-off behavior of the IGBT transistor is similar and will not be elaborated further here.

[0041] (4) Control of switch delay time

[0042] The switching delay time can be controlled by a PWM waveform control signal issued by the MCU. Figure 4 Only one PWM waveform is shown as an example for explanation, such as Figure 4 As shown:

[0043] The SiC transistor is turned on first and then turned off, where Tdelayon is the turn-on delay time and Tdelayoff is the turn-off delay time.

[0044] When it is necessary to control Tdelay on and Tdelay off, the PWM_SiC control signal issued by the internal switching logic processing and delay control module of the MCU will advance the Tdelay on time of the PWM_IGBT signal when turning on and lag the Tdelay off time of the PWM_IGBT signal when turning off. This realizes the time control of the signal issued by the MCU. The PWM_SiC and PWM_IGBT signals are driven and processed by the SiC driver chip and the IGBT driver chip respectively, and then sent to the SiC transistor and the IGBT transistor respectively to realize the control of the switching delay time of the hybrid power module.

[0045] The process of turning the IGBT transistor on first and then off, with the turn-on delay Tdelay on time and the turn-off delay Tdelay off time, follows the same principle as above, and will not be repeated here.

[0046] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A discrete drive circuit for a SiC-IGBT hybrid power module, characterized in that, include: MCU, SiC driver chip, IGBT driver chip, half-bridge circuit; The signal input terminal of the SiC driver chip is used to receive the SiC_PWM control signal sent by the MCU, and the drive signal output terminal is connected to the signal input terminal A of the half-bridge circuit. The signal input terminal of the IGBT driver chip is used to receive the IGBT_PWM control signal sent by the MCU, and the drive signal output terminal is connected to the signal input terminal B of the half-bridge circuit. The power signal input terminal C of the half-bridge circuit is connected to the bus DC+, and the power signal input terminal D is connected to the bus DC-.

2. The SiC-IGBT hybrid power module discrete drive circuit according to claim 1, characterized in that, The power signal input terminal of the SiC driver chip is powered through VCC_SiC; the negative voltage power supply terminal is powered through VEE_SiC.

3. The SiC-IGBT hybrid power module discrete drive circuit according to claim 1, characterized in that, The power input terminal of the IGBT driver chip is powered through VCC_IGBT; the negative voltage power supply terminal is powered through VEE_IGBT.

4. The SiC-IGBT hybrid power module discrete drive circuit according to claim 1, characterized in that, The half-bridge circuit includes: an upper-bridge SiC transistor, an upper-bridge IGBT transistor, a lower-bridge SiC transistor, a lower-bridge IGBT transistor, a resistor R2, a gate capacitor C1, a resistor R4, and a gate capacitor C2; wherein: The gate of the upper bridge SiC transistor is connected to the signal input terminal A through a set driving resistor R1; The base of the upper bridge IGBT transistor is connected to the signal input terminal B through the set drive resistor R3; The drain of the upper bridge SiC transistor and the collector of the upper bridge IGBT transistor are connected in series and then connected to the power signal input terminal C. The source of the upper bridge SiC transistor is connected in series with the emitter of the upper bridge IGBT transistor, and then connected to the drain of the lower bridge SiC transistor and the collector of the lower bridge IGBT transistor. The source of the lower bridge SiC transistor is connected in series with the emitter of the lower bridge IGBT transistor and then connected to the power signal input terminal D. One end of the resistor R2 connected in parallel with the gate capacitor C1 is connected to the gate of the upper bridge SiC transistor, and the other end is connected to the source of the upper bridge SiC transistor. One end of the resistor R4 connected in parallel with the gate capacitor C2 is connected to the base of the upper bridge IGBT transistor, and the other end is connected to the emitter of the upper bridge IGBT transistor.

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