A current proportional regulation method suitable for SiC / Si hybrid devices

Abstract

This invention provides a current ratio adjustment method suitable for SiC / Si hybrid parallel devices. It involves sampling the case temperature of the SiC MOSFET and Si IGBT in the SiC / Si hybrid parallel device using a temperature sampling circuit; inputting the sampled case temperature to a digital controller; and then, after online calculation by the digital controller to obtain the device junction temperature, outputting a signal to dynamically adjust the forward drive voltage of the device drive circuit, thereby achieving dynamic adjustment of the current ratio of the SiC / Si hybrid parallel device. The drive circuit includes: a forward drive voltage linear adjustment circuit, a forward drive voltage selection circuit, a totem-pole structure circuit between the forward and negative drive voltages, and a drive resistor. This invention enables dynamic adjustment of the current ratio of SiC / Si hybrid parallel devices, reduces the current stress on individual devices, improves the thermal balance of the SiC / Si hybrid parallel devices, and enhances their reliability.

Description

Technical Field

[0001] This invention belongs to the fields of power electronics and electrical engineering, and relates to a current ratio adjustment method applicable to SiC / Si hybrid parallel devices, and particularly to a control method for dynamically adjusting the current ratio based on the internal junction temperature imbalance of the hybrid parallel device. Background Technology

[0002] To leverage the high-current conduction advantages of Si IGBTs and the switching advantages of SiC MOSFETs, low-current SiC MOSFETs and high-current Si IGBTs can be coupled in parallel. By designing a turn-on-then-turn-off switching mode for the SiC MOSFETs, the hybrid parallel device can exhibit the high-speed switching characteristics of SiC MOSFETs. However, due to the uneven current distribution within the hybrid parallel device, and the fact that the SiC MOSFETs also bear switching losses, the low-current SiC MOSFETs, acting as auxiliary devices, may overheat, even exceeding the maximum junction temperature limit. This exacerbates the aging and failure issues of the SiC MOSFETs, limiting the power capability of the hybrid parallel device.

[0003] Current research on the current ratio problem in SiC / Si hybrid parallel devices commonly uses junction temperature prediction models to pre-select SiC MOSFETs and Si IGBTs with appropriate rated current ratios for hybrid parallel operation. This approach comprehensively considers device reliability and cost when selecting suitable SiC MOSFETs and Si IGBTs for hybrid parallel operation. However, for a given SiC / Si hybrid parallel device, this method cannot address the thermal stress problem caused by uneven internal current distribution during operation online. Summary of the Invention

[0004] The purpose of this invention is to provide a current ratio adjustment method suitable for SiC / Si hybrid parallel devices. By dynamically adjusting the forward drive voltage of the device to adjust the current ratio, the internal junction temperature imbalance of the hybrid parallel device is reduced, ensuring the reliability of the device and improving the power capacity of the converter.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention proposes a current proportional adjustment method suitable for SiC / Si hybrid devices, comprising:

[0007] Step 1: Sample the case temperature of the SiC MOSFET and Si IGBT in the SiC / Si hybrid parallel device through a temperature sampling circuit and input it into the digital controller; wherein, the SiC / Si hybrid parallel device includes a SiC MOSFET and a Si IGBT connected in parallel across the SiC MOSFET;

[0008] Step 2: The junction temperature of the device is obtained through online calculation by the digital controller, and the output signal is used to dynamically adjust the forward drive voltage of the device drive circuit, thereby realizing the dynamic adjustment of the current ratio of the SiC / Si hybrid parallel device.

[0009] Furthermore, the online calculation process of the digital controller includes:

[0010] Step 2.1, Loss Calculation: Calculate the switching delay time T of the hybrid parallel devices. on_delay T off_delay The sampling circuit inputs signals such as case temperature, voltage, and current to the digital controller to calculate the loss P. loss ;

[0011] P loss =P loss_IGBT +P loss_MOS (3)

[0012] =[Df sw ·(T on_delay +T off_delay )]·(E cond_IGBT +E cond_MOS )+f sw ·(E off_IGBT +E on_IGBT +E off_MOS +E on_MOS )

[0013] Step 2.2, Junction Temperature Calculation: Based on the device thermal network model and the case temperature T c Calculate the junction temperature T of the device j ;

[0014] T j =T c +R th(j-c) P loss (4)

[0015] Step 2.3, Normalization: Normalize the device junction temperature T j_MOS T j_IGBT Divide by the maximum tolerable junction temperature to obtain the normalized junction temperature T. j_MOS * T j_IGBT * ;

[0016] Step 2.4, compare junction temperatures: compare the normalized junction temperatures of the SiC MOSFET and the Si IGBT, and output a signal based on the comparison relationship to dynamically adjust the forward drive voltage of the device drive circuit.

[0017] Furthermore, the current ratio of the hybrid parallel devices is dynamically adjusted based on the junction temperature imbalance between the SiC MOSFET and Si IGBT. Since the maximum tolerable junction temperatures of the SiC MOSFET and Si IGBT differ, the normalized junction temperature obtained by dividing the device junction temperature by the maximum tolerable junction temperature is used for comparison.

[0018] When T j_MOS * >T j_IGBT * At that time, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS(1) The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT(3) ;

[0019] When T j_MOS * <T j_IGBT * At that time, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS(3) The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT(1) ;

[0020] When T j_MOS * =T j_IGBT * The forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS(2) The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT(2) .

[0021] Furthermore, the magnitude relationship of the forward drive voltage of the SiC MOSFET is V DRV_MOS(3) >V DRV_MOS(2) >V DRV_MOS(1) The magnitude relationship of the forward drive voltage of Si IGBT is V DRV_IGBT(3) >V DRV_IGBT(2) >V DRV_IGBT(1) Among them, V DRV_MOS(2) V DRV_IGBT(2) The recommended forward drive voltage is specified in the device datasheet; other forward drive voltages V0 DRV_MOS(3) V DRV_IGBT(3) V DRV_MOS(1) V DRV_IGBT(1) All values ​​fluctuate around the recommended drive voltage, and are less than the device's gate withstand voltage but greater than the device's turn-on threshold voltage.

[0022] Furthermore, the driving circuit is connected to the gates of the SiC MOSFET and Si IGBT respectively. The driving circuit includes a positive drive voltage linear adjustment circuit, a positive drive voltage selection circuit, and a totem pole structure circuit connected in sequence. The positive drive voltage linear adjustment circuit provides a negative drive voltage and positive drive voltages of different magnitudes. The positive drive voltage selection circuit selects one positive drive voltage. The totem pole structure circuit is connected between the positive drive voltage and the negative drive voltage and is connected to the gates of the SiC MOSFET and Si IGBT through a driving resistor.

[0023] Furthermore, the positive drive voltage linear regulation circuit includes an isolated modular power supply and a low-dropout linear regulator connected in series; wherein, the isolated modular power supply provides a positive supply voltage and a negative supply voltage for the drive circuit; the low-dropout linear regulator includes a first linear regulator, a second linear regulator and a third linear regulator connected in parallel to each other, which step down the positive supply voltage provided by the modular power supply into three positive drive voltages of different magnitudes.

[0024] Furthermore, the forward drive voltage selection circuit includes a first control transistor S1, a second control transistor S2, and a third control transistor S3, which are respectively connected to the first linear voltage regulator, the second linear voltage regulator, and the third linear voltage regulator. By changing the drive signal of the control transistor, the forward drive voltage can be selected.

[0025] Furthermore, the totem pole structure circuit includes the switching control transistor S. on and the shutdown control tube S off Among them, the control tube S is turned on. on The drain is connected to the forward drive voltage, turning on the control transistor S. on Source and turn-off control transistor S off The drain and drive resistor are connected, turning off the control transistor S. off The source is connected to the negative supply voltage, turning on the control transistor S. on and the shutdown control tube S off The gates all receive a given PWM signal.

[0026] Furthermore, let S1, S2, and S3 represent the first control transistor S in the SiC MOSFET forward drive voltage selection circuit, respectively. 1(MOS) Second control tube S 2(MOS) Third control tube S 3(MOS) The drive signals control the selection of V respectively. DRV_MOS(1) V DRV_MOS(2) V DRV_MOS(3) S4, S5, and S6 represent the first control transistor S in the Si IGBT forward drive voltage selection circuit, respectively. 1(IGBT) Second control tube S 2(IGBT) Third control tube S3(IGBT) The drive signals control the selection of V respectively. DRV_IGBT(1) V DRV_IGBT(2) V DRV_IGBT(3) .

[0027] Furthermore, when T j_MOS * >T j_IGBT * When the drive signals S1 and S6 are high, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS(1) The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT(3) ;

[0028] When T j_MOS * <T j_IGBT * When drive signals S3 and S4 are high, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS(3) The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT(1) ;

[0029] When T j_MOS * =T j_IGBT * When the drive signals S2 and S5 are high, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS(2) The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT(2) .

[0030] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0031] (1) When the normalized junction temperature of SiC MOSFET is greater than that of Si IGBT, the digital controller will dynamically adjust the forward drive voltage to reduce the current flowing through SiC MOSFET and reduce the thermal stress of the device.

[0032] (2) When the normalized junction temperature of SiC MOSFET is less than that of Si IGBT, the digital controller will dynamically adjust the forward drive voltage to reduce the current flowing through Si IGBT and reduce the thermal stress of the device.

[0033] (3) When the normalized junction temperature of SiC MOSFET is close to that of Si IGBT, the forward drive voltage is adjusted to the forward drive voltage recommended in the device manual, which can balance switching losses and gate safety and improve the reliability of the converter.

[0034] (4) The forward drive voltage can be flexibly adjusted by using a linear voltage regulator. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a current ratio adjustment method for SiC / Si hybrid devices proposed in this invention.

[0036] Figure 2 This is the equivalent circuit diagram of the SiC / Si hybrid parallel device described in this invention.

[0037] Figure 3 This is a schematic diagram illustrating the variation of the on-resistance of the switching transistor with the forward drive voltage as described in this invention;

[0038] Figure 4 This is a schematic diagram of the dynamic adjustment and control method for the current ratio of SiC / Si hybrid parallel devices described in this invention. Detailed Implementation

[0039] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] like Figure 1 The diagram shows a current ratio adjustment method for SiC / Si hybrid parallel devices proposed in this invention, including: SiC / Si hybrid parallel devices, a digital controller, a positive drive voltage linear adjustment circuit, a positive drive voltage selection circuit, a totem pole structure circuit between the positive drive voltage and the negative drive voltage, and a drive resistor.

[0041] The SiC / Si hybrid parallel device includes a SiC MOSFET and a Si IGBT connected in parallel across the SiC MOSFET. The gates of the SiC MOSFET and the Si IGBT are respectively connected to a driving circuit. The driving circuit includes a forward drive voltage linear adjustment circuit, a forward drive voltage selection circuit, and a totem pole structure circuit connected in sequence.

[0042] The forward drive voltage linear regulation circuit includes an isolated modular power supply and a low-dropout linear regulator connected in series. The isolated modular power supply provides the forward and negative supply voltages to the drive circuit. The low-dropout linear regulator includes a first linear regulator, a second linear regulator, and a third linear regulator connected in parallel to each other, which step down the forward supply voltage provided by the modular power supply into three forward drive voltages of different magnitudes.

[0043] Among them, the forward drive voltages of the SiC MOSFET are V DRV_MOS(1) V DRV_MOS(2) V DRV_MOS(3) The relationship is V DRV_MOS(3) >V DRV_MOS(2) >V DRV_MOS(1) The forward drive voltages of the Si IGBT are V. DRV_IGBT(1)V DRV_IGBT(2) V DRV_IGBT(3) The relationship is V DRV_IGBT(3) >V DRV_IGBT(2) >V DRV_IGBT(1) Among them, V DRV_MOS(2) V DRV_IGBT(2) This is the recommended forward drive voltage from the device datasheet. All other forward drive voltages are increased or decreased based on the recommended drive voltage.

[0044] The forward drive voltage selection circuit includes a first control transistor S1, a second control transistor S2, and a third control transistor S3, which are respectively connected to a first linear voltage regulator, a second linear voltage regulator, and a third linear voltage regulator. By changing the drive signal of the control transistor, the forward drive voltage can be selected.

[0045] Among them, S1, S2, and S3 are the first control transistors S1, S2, and S3 in the SiC MOSFET forward drive voltage selection circuit, respectively. 1(MOS) Second control tube S 2(MOS) Third control tube S 3(MOS) The drive signals. S4, S5, and S6 are the first control transistor S in the Si IGBT forward drive voltage selection circuit. 1(IGBT) Second control tube S 2(IGBT) Third control tube S 3(IGBT) The driving signal.

[0046] The totem pole structure circuit is connected between the positive drive voltage and the negative drive voltage, including the turn-on control transistor S. on and the shutdown control tube S off Among them, the control tube S is turned on. on The drain is connected to the forward drive voltage, turning on the control transistor S. on Source and turn-off control transistor S off The drain and drive resistor are connected, turning off the control transistor S. off The source is connected to the negative supply voltage, turning on the control transistor S. on and the shutdown control tube S off The gates all receive a given PWM signal.

[0047] The current proportional regulation method applicable to SiC / Si hybrid devices includes the following steps:

[0048] Step 1: Sample the case temperature of the SiC MOSFET and Si IGBT in the SiC / Si hybrid parallel device through a temperature sampling circuit and input it into the digital controller; wherein, the SiC / Si hybrid parallel device includes a SiC MOSFET and a Si IGBT connected in parallel across the SiC MOSFET.

[0049] Step 2: The junction temperature of the device is obtained through online calculation by the digital controller, and the output signal is used to dynamically adjust the forward drive voltage of the device drive circuit, thereby realizing the dynamic adjustment of the current ratio of the SiC / Si hybrid parallel device.

[0050] like Figure 4 The diagram shows a schematic of the dynamic current ratio adjustment and control method for SiC / Si hybrid parallel devices described in this invention, including:

[0051] Loss calculation module: calculates the switching delay time T of the hybrid parallel devices. on_delay T off_delay The sampling circuit inputs signals such as case temperature, voltage, and current into the digital controller to calculate the loss P. loss ;

[0052] P loss =P loss_IGBT +P loss_MOS

[0053] =[Df sw ·(T on_delay +T off_delay )]·(E cond_IGBT +E cond_MOS )+f sw ·(E off_IGBT +E on_IGBT +E off_MOS +E on_MOS )

[0054] Where P represents loss, the subscripts IGBT and MOS represent Si IGBT and SiC MOSFET respectively, D represents the duty cycle of the SiC / Si hybrid device, and f sw E represents the switching frequency of the SiC / Si hybrid device. cond E represents conduction loss. on E represents turn-on loss. off This represents shutdown loss.

[0055] Junction temperature calculation module: Based on the device thermal network model and case temperature T c Calculate the junction temperature T of the device j ;

[0056] T j =T c +R th(j-c) P loss

[0057] Among them, R th(j-c) Indicates the thermal resistance from the internal junction to the surface shell of the device.

[0058] Normalization module: This module sets the device junction temperature T... j_MOS T j_IGBTDivide by the maximum tolerable junction temperature to obtain the normalized junction temperature T. j_MOS * T j_IGBT * ;

[0059] Junction temperature comparison module: compares the normalized junction temperature of SiC MOSFET and Si IGBT, and outputs a signal based on the comparison relationship to dynamically adjust the forward drive voltage of the device drive circuit.

[0060] Specifically, the current ratio of the hybrid parallel devices is dynamically adjusted based on the junction temperature imbalance between the SiC MOSFET and Si IGBT. Since the maximum tolerable junction temperatures of the SiC MOSFET and Si IGBT differ, the normalized junction temperature obtained by dividing the device's junction temperature by its maximum tolerable junction temperature is used for comparison.

[0061] When the normalized junction temperature T of the SiC MOSFET j_MOS * The normalized junction temperature T is greater than that of Si IGBT. j_IGBT * When the drive signals S1 and S6 are high, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS(1) The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT(3) ;

[0062] When the normalized junction temperature T of the SiC MOSFET j_MOS * Less than the normalized junction temperature T of Si IGBT j_IGBT * When drive signals S3 and S4 are high, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS(3) The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT(1) ;

[0063] When the normalized junction temperature T of the SiC MOSFET j_MOS * The normalized junction temperature T of Si IGBT j_IGBT * When they approach, drive signals S2 and S5 are set high, and the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS(2) The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT(2) .

[0064] like Figure 2 The diagram shown is the equivalent circuit diagram of the SiC / Si hybrid parallel device described in this invention, where the SiC MOSFET is equivalent to the on-resistance R. DS(on) , IMOS The current flowing through the SiC MOSFET; the equivalent on-resistance of the Si IGBT is R. CE(on) and a constant voltage source U whose magnitude is its threshold voltage T0 , I IGBT I represents the current flowing through the Si IGBT; L This is the load current.

[0065] like Figure 3 The diagram shows the variation of the on-resistance of the switching transistor as a function of the forward drive voltage, as described in this invention. The horizontal axis represents the forward drive voltage, and the vertical axis represents the on-resistance R of the switching transistor. DS(on) The on-resistance of the switching transistor decreases as the forward drive voltage increases.

[0066] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A current proportional adjustment method suitable for SiC / Si hybrid devices, characterized in that, Includes the following steps: Step 1: Sample the case temperature of the SiC MOSFET and Si IGBT in the SiC / Si hybrid parallel device through a temperature sampling circuit and input it into the digital controller; wherein, the SiC / Si hybrid parallel device includes a SiC MOSFET and a Si IGBT connected in parallel across the SiC MOSFET; Step 2: The junction temperature of the device is obtained through online calculation by the digital controller, and the output signal is used to dynamically adjust the forward drive voltage of the device drive circuit, thereby realizing the dynamic adjustment of the current ratio of the SiC / Si hybrid parallel device. The online calculation process of the digital controller includes: Step 2.1, Loss Calculation: Calculate the switching delay time T of the hybrid parallel devices. on_delay T off_delay The sampling circuit inputs the case temperature, voltage, and current signals to the digital controller to calculate the loss P. loss ; (1) Where P represents loss, the subscripts IGBT and MOS represent Si IGBT and SiC MOSFET respectively, D represents the duty cycle of the SiC / Si hybrid device, and f sw E represents the switching frequency of the SiC / Si hybrid device. cond E represents conduction loss. on E represents turn-on loss. off Represents shutdown loss; Step 2.2, Junction Temperature Calculation: Based on the hybrid parallel device thermal network model and the case temperature T... c Calculate the junction temperature T of the device j ; (2) Among them, R th(j-c) This indicates the thermal resistance from the internal junction to the surface shell of the device; Step 2.3, Normalization: Normalize the device junction temperature T j_MOS T j_IGBT Divide by the maximum tolerable junction temperature to obtain the normalized junction temperature T of the SiC MOSFET. j_MOS * and the normalized junction temperature T of Si IGBT j_IGBT * ; Step 2.4, Junction Temperature Comparison: Compare the normalized junction temperatures of the SiC MOSFET and the Si IGBT. Based on the comparison relationship, output a signal to dynamically adjust the forward drive voltage of the device drive circuit, thereby achieving dynamic adjustment of the current ratio of the SiC / Si hybrid parallel device. The dynamic adjustment method is as follows: When T j_MOS * >T j_IGBT * At that time, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS1 The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT3 ; When T j_MOS * <T j_IGBT * At that time, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS3 The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT1 ; When T j_MOS * =T j_IGBT * At that time, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS2 The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT2 ; The magnitude relationship of the forward drive voltage of the SiC MOSFET is V. DRV_MOS3 >V DRV_MOS2 >V DRV_MOS1 The magnitude relationship of the forward drive voltage of Si IGBT is V DRV_IGBT3 >V DRV_ IGBT2 >V DRV_ IGBT1 V DRV_MOS2 V DRV_ IGBT2 This is the standard forward drive voltage; other forward drive voltages V DRV_MOS3 V DRV_IGBT3 V DRV_MOS1 V DRV_IGBT1 Both are less than the gate withstand voltage of the device and greater than the turn-on threshold voltage of the device.

2. The current ratio adjustment method for SiC / Si hybrid devices according to claim 1, characterized in that, The driving circuit is connected to the gates of the SiC MOSFET and Si IGBT respectively. The driving circuit includes a positive drive voltage linear adjustment circuit, a positive drive voltage selection circuit, and a totem pole structure circuit connected in sequence. The positive drive voltage linear adjustment circuit provides a negative drive voltage and positive drive voltages of different magnitudes. The positive drive voltage selection circuit selects one positive drive voltage. The totem pole structure circuit is connected between the positive drive voltage and the negative drive voltage and is connected to the gates of the SiC MOSFET and Si IGBT through a driving resistor.

3. The current ratio adjustment method for SiC / Si hybrid devices according to claim 2, characterized in that, The positive drive voltage linear regulation circuit includes an isolated modular power supply and a low-dropout linear regulator connected in series. The isolated modular power supply provides a positive supply voltage and a negative supply voltage to the drive circuit. The low-dropout linear regulator includes a first linear regulator, a second linear regulator, and a third linear regulator connected in parallel to each other, which step down the positive supply voltage provided by the modular power supply into three positive drive voltages of different magnitudes.

4. The current ratio adjustment method for SiC / Si hybrid devices according to claim 3, characterized in that, The forward drive voltage selection circuit includes a first control transistor, a second control transistor, and a third control transistor, which are respectively connected to a first linear voltage regulator, a second linear voltage regulator, and a third linear voltage regulator. By changing the drive signal of the control transistor, the forward drive voltage can be selected.

5. The current ratio adjustment method for SiC / Si hybrid devices according to claim 4, characterized in that, The totem pole structure circuit includes an on / off control transistor S. on and the shutdown control tube S off Among them, the control tube S is turned on. on The drain is connected to the forward drive voltage, turning on the control transistor S. on Source and turn-off control transistor S off The drain and drive resistor are connected, turning off the control transistor S. off The source is connected to the negative supply voltage, turning on the control transistor S. on and the shutdown control tube S off The gates all receive a given PWM signal.

6. The current proportional adjustment method for SiC / Si hybrid devices according to any one of claims 1-5, characterized in that, Let S1, S2, and S3 represent the first control transistor S in the SiC MOSFET forward drive voltage selection circuit. 1MOS Second control tube S 2MOS Third control tube S 3MOS The drive signals control the selection of V respectively. DRV_MOS1 V DRV_MOS2 V DRV_MOS3 Let S4, S5, and S6 represent the first control transistor S in the forward drive voltage selection circuit of the Si IGBT, respectively. 1IGBT Second control tube S 2IGBT Third control tube S 3IGBT The drive signals control the selection of V respectively. DRV_IGBT1 V DRV_IGBT2 V DRV_IGBT3 .

7. The current proportional adjustment method for SiC / Si hybrid devices according to claim 6, characterized in that, When T j_MOS * >T j_IGBT * When the drive signals S1 and S6 are high, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS1 The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT3 ; When T j_MOS * <T j_IGBT * When drive signals S3 and S4 are high, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS3 The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT1 ; When T j_MOS * =T j_IGBT * When the drive signals S2 and S5 are high, the forward drive voltage of the SiC MOSFET is adjusted to V. DRV_MOS2 The forward drive voltage of the Si IGBT is adjusted to V. DRV_IGBT2 .

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