Hybrid switch device

Abstract

A hybrid switching device includes a first switching element, a second switching element, and a controller. The first switching element is independently controllable. The second switching element is in parallel with the first switching element, and the second switching element is independently controllable. The controller is configured to generate a control signal and to control the first switching element and the second switching element according to a power operating point of an operating curve. The control signal controls the first switching element to be on at light loads below the power operating point, and the control signal controls the second switching element to be on at heavy loads above the power operating point, thereby optimizing switching efficiency of the first switching element and the second switching element in a hybrid operation.

Description

Technical Field

[0001] This invention relates to a hybrid switching device, and more particularly to a hybrid switching device that combines a silicon carbide-based metal oxide semiconductor field-effect transistor and a silicon-based insulated gate bipolar transistor. Background Technology

[0002] When using power transistor switches, a single switching element is usually not suitable for all operating conditions. For example, a single switching element has its advantages and disadvantages under light load and heavy load conditions. Therefore, using only a single switching element for operation under different conditions will not achieve optimal performance.

[0003] Therefore, how to design a hybrid switching device, especially a hybrid switching device that combines silicon carbide-based metal oxide semiconductor field-effect transistors and silicon-based insulated gate bipolar transistors, to solve the problems and technical bottlenecks of the existing technology, is an important research topic for the inventors of this case. Summary of the Invention

[0004] The present invention aims to provide a hybrid switching device. The hybrid switching device includes a first switching element, a second switching element, and a controller. The first switching element can be controlled independently. The second switching element is connected in parallel with the first switching element and can also be controlled independently. The controller generates a control signal and controls the first and second switching elements respectively according to the power operating point of the operating curve. Specifically, under light load conditions below the power operating point, the control signal controls the first switching element to conduct; under heavy load conditions above the power operating point, the control signal controls the second switching element to conduct, thereby optimizing the switching efficiency under hybrid operation of the first and second switching elements.

[0005] In one embodiment, under light load conditions below the power operating point, the control signal controls the second switching element to turn off; under heavy load conditions above the power operating point, the control signal controls the first switching element to turn off.

[0006] In one embodiment, under light load conditions below the power operating point, the operating curve is the first forward characteristic curve of the first switching element; under heavy load conditions above the power operating point, the operating curve is the second forward characteristic curve of the second switching element.

[0007] In one embodiment, the first switching element is a metal-oxide-semiconductor field-effect transistor, and the second switching element is an insulated-gate bipolar transistor.

[0008] In one embodiment, the metal-oxide-semiconductor field-effect transistor is a silicon carbide-based metal-oxide-semiconductor field-effect transistor, and the insulated-gate bipolar transistor is a silicon-based insulated-gate bipolar transistor.

[0009] In one embodiment, the silicon carbide-based metal-oxide-semiconductor field-effect transistor includes a first switch, a second resistor, a third resistor, and a first diode. The first resistor is connected in series with the first switch to form a first series path. The first diode is connected in series with the second resistor to form a second series path. The first series path is connected in parallel with the second series path.

[0010] In one embodiment, the silicon-based insulated-gate bipolar transistor includes a second switch, a second diode, a third resistor, a fourth resistor, and the third diode. The second diode is connected in series with the second switch. The third resistor is connected in series with the second diode to form a third series path. The third diode is connected in series with the fourth resistor to form a fourth series path. The third series path is connected in parallel with the fourth series path.

[0011] In one embodiment, the number of second switching elements is greater than the number of first switching elements.

[0012] In one embodiment, the ratio of the number of first switching elements to the number of second switching elements is 1:3.

[0013] In one embodiment, the ratio of the number of first switching elements to the number of second switching elements is 2:2.

[0014] In one embodiment, the control signal includes a first control signal and a second control signal, used to control the first switching element and the second switching element respectively.

[0015] In one embodiment, when the number of silicon carbide-based metal-oxide-semiconductor field-effect transistors (MOSFETs) and the number of silicon-based insulated-gate bipolar transistors (IGBTs) are each one, the portion of the total current allocated to the MOSFETs is I_total * I_SiC_ratio, and the portion of the total current allocated to the IGBTs is I_total * (1 - I_SiC_ratio). Here, I_total represents the total current, and I_SiC_ratio represents the proportion of the total current allocated to the MOSFETs.

[0016] In one embodiment, when the forward voltage of the silicon carbide-based metal-oxide-semiconductor field-effect transistor is less than the starting voltage of the silicon-based insulated-gate bipolar transistor, I_SiC_ratio is 1; when the forward voltage of the silicon carbide-based metal-oxide-semiconductor field-effect transistor is less than the forward voltage of the silicon-based insulated-gate bipolar transistor, I_SiC_ratio is less than 1 and greater than 0.5; when the forward voltage of the silicon carbide-based metal-oxide-semiconductor field-effect transistor is equal to the forward voltage of the silicon-based insulated-gate bipolar transistor, I_SiC_ratio is equal to 0.5; when the forward voltage of the silicon carbide-based metal-oxide-semiconductor field-effect transistor is greater than the forward voltage of the silicon-based insulated-gate bipolar transistor, I_SiC_ratio is less than 0.5 and greater than 0.

[0017] In one embodiment, when the number of silicon carbide-based metal oxide semiconductor field-effect transistors is one and the number of silicon-based insulated-gate bipolar transistors is N, where N is a positive integer greater than 1, the silicon carbide-based metal oxide semiconductor field-effect transistor is controlled to operate at the optimal power efficiency point to flow through a portion of the total current, and the remaining N silicon-based insulated-gate bipolar transistors flow the remaining current.

[0018] Therefore, the hybrid switching device provided by the present invention has the following features and advantages: The design strategy of the present invention combines the use of SiC-MOSFET and Si-IGBT to give full play to the advantages of both under different operating conditions and to complement their shortcomings, thereby achieving the best performance and efficiency of the system using the hybrid switching device.

[0019] To gain a deeper understanding of the techniques, means, and effects employed by this invention to achieve its intended purpose, please refer to the following detailed description and accompanying drawings. It is believed that the purpose, features, and characteristics of this invention can be understood in a thorough and specific manner from these drawings. However, the drawings are provided for reference and illustration only and are not intended to limit the scope of this invention. Attached Figure Description

[0020] Figure 1 : This is a waveform diagram showing the forward characteristics of the first and second switching elements of the hybrid switching device of the present invention;

[0021] Figure 2A : This is a circuit symbol diagram of the first switching element of the present invention, which is a silicon carbide-based metal oxide semiconductor field-effect transistor;

[0022] Figure 2B :for Figure 2A Equivalent circuit diagram of silicon carbide-based metal-oxide-semiconductor field-effect transistor;

[0023] Figure 3A : This is a circuit symbol diagram of the second switching element of the present invention, which is a silicon-based insulated gate bipolar transistor;

[0024] Figure 3B :for Figure 3A Equivalent circuit diagram of a silicon-based insulated gate bipolar transistor;

[0025] Figure 4A : This is a circuit diagram showing the parallel use of the hybrid switching device of the present invention;

[0026] Figure 4B :for Figure 4A Equivalent circuit diagram of parallel use of hybrid switching devices;

[0027] Figure 5 : A circuit diagram of a preferred embodiment of the application of the hybrid switching device of the present invention;

[0028] Figure 6 : This is a waveform diagram showing the forward characteristics of the first and second switching elements of the hybrid switching device of the present invention, as well as the forward characteristics under hybrid drive.

[0029] Explanation of icon numbers

[0030] 100: Hybrid switching device

[0031] 10: First switching element

[0032] 20: Second switching element

[0033] 11: First Switch

[0034] 12: First resistor

[0035] 13: Second resistor

[0036] 14: First Diode

[0037] 21: Second Switch

[0038] 22: Second diode

[0039] 23: Third resistor

[0040] 24: Fourth resistor

[0041] 25: Third Diode

[0042] 50: Controller

[0043] CV1: First forward characteristic curve

[0044] CV2: Second forward characteristic curve

[0045] P: Power Operating Point

[0046] Sc: Control signal

[0047] Sc1: First control signal

[0048] Sc2: Second control signal

[0049] BU: Upper Bridge Arm

[0050] BL: Lower bridge arm Detailed Implementation

[0051] The technical content and detailed description of the present invention are explained below in conjunction with the accompanying drawings.

[0052] Please see Figure 1 The diagram shown is a circuit symbol of a silicon carbide-based metal-oxide-semiconductor field-effect transistor (MOSFET) as the first switching element of the present invention. Specifically, the hybrid switching device includes a first switching element 10 and a second switching element 20, wherein, as shown... Figure 1 As shown, this includes the forward characteristic of the first switching element 10 and the forward characteristic of the second switching element 20. From Figure 1 As can be seen, the horizontal axis represents the forward voltage of the switching element, and the vertical axis represents the forward current of the switching element. Furthermore, Figure 1 The forward characteristic curve of the first switching element 10, namely the first forward characteristic curve CV1, is further revealed, as is the forward characteristic curve of the second switching element 20, namely the second forward characteristic curve CV2.

[0053] In the foregoing embodiments, the first switching element 10 and the second switching element 20 may be, but are not limited to, any power semiconductor element type selected from insulated-gate bipolar transistors, silicon carbide power elements, silicon power elements, and / or gallium nitride power elements; wherein the first switching element 10 and the second switching element 20 are power semiconductor elements with different forward characteristics; when below the power operating point P, under the same forward voltage, the forward current of the first switching element 10 is higher than that of the second switching element 20; and when above the power operating point P, under the same forward voltage, the forward current of the first switching element 10 is lower than that of the second switching element 20; therefore, the hybrid switching device of the present invention combines the advantages of the first switching element 10 and the second switching element 20, and when the forward current is above the power operating point P, the second switching element 20 is used as the operating switch.

[0054] In the foregoing embodiments, the first switching element 10 and the second switching element 20 are further power semiconductor elements of different power semiconductor element types and have different forward characteristics.

[0055] Please see Figure 2A and Figure 2B The circuit symbol diagrams for the first switching element 10 of the present invention being a silicon carbide-based metal-oxide-semiconductor field-effect transistor and the circuit symbol diagram for the first switching element 10 being a silicon carbide-based metal-oxide-semiconductor field-effect transistor are shown below. Figure 2A Equivalent circuit diagram of a silicon carbide-based metal-oxide-semiconductor field-effect transistor; and Figure 3A and Figure 3B The figures shown are circuit symbol diagrams of the second switching element 20 of the present invention, which is a silicon-based insulated gate bipolar transistor. Figure 3A Equivalent circuit diagram of a silicon-based insulated-gate bipolar transistor (IGBT). In this invention, the first switching element 10 is a metal-oxide-semiconductor field-effect transistor (MOSFET), and the second switching element 20 is an insulated-gate bipolar transistor (IGBT). More specifically, the MOSFET is a silicon carbide-based MOSFET (SiC-MOSFET), and the IGBT is a silicon-based IGBT (Si-IGBT).

[0056] like Figure 2B As shown, the first switching element 10, namely a silicon carbide-based metal-oxide-semiconductor field-effect transistor, includes a first switch 11, a first resistor 12, a second resistor 13, and a first diode 14. The first resistor 12 is connected in series with the first switch 11 to form a first series path. The first diode 14 is connected in series with the second resistor 13 to form a second series path. The first series path is connected in parallel with the second series path.

[0057] like Figure 3B As shown, the second switching element 20, i.e., the silicon-based insulated-gate bipolar transistor, includes a second switch 21, a second diode 22, a third resistor 23, a fourth resistor 24, and a third diode 25. The second diode 22 is connected in series with the second switch 21. The third resistor 23 is connected in series with the second diode 22 to form a third series path. The third diode 25 is connected in series with the fourth resistor 24 to form a fourth series path. The third series path is connected in parallel with the fourth series path.

[0058] Depend on Figure 1 The two forward characteristic curves CV1 and CV2 are used to compare the forward characteristics of the first switching element 10 and the second switching element. For the first switching element 10, which is a silicon carbide-based metal-oxide-semiconductor field-effect transistor (SiC-MOSFET), the horizontal axis represents the forward voltage of the SiC-MOSFET, Vds, which is the voltage drop when current is conducting. For the second switching element 20, which is a silicon-based insulated-gate bipolar transistor (Si-IGBT), the horizontal axis represents the forward voltage of the Si-IGBT, Vce. Furthermore, for the first switching element 10, which is a silicon carbide-based metal-oxide-semiconductor field-effect transistor (SiC-MOSFET), the vertical axis represents the forward current of the SiC-MOSFET, Ids, which is the magnitude of the current that the switching element can conduct. For the second switching element 20, which is a silicon-based insulated-gate bipolar transistor (Si-IGBT), the vertical axis represents the forward current of the Si-IGBT, Ice.

[0059] Furthermore, for the first switching element 10 (see the first forward characteristic curve CV1), its curve is closer to linear, indicating a lower on-state voltage drop. Therefore, the first switching element 10 is more advantageous under high-frequency and high-current conditions. For the second switching element 20 (see the second forward characteristic curve CV2), at lower forward voltages, the forward current flowing through it is very small. Only after the forward voltage exceeds approximately 1 volt does the forward current begin to rise rapidly. Therefore, the second switching element 20 has a higher on-state voltage drop under high-current conditions.

[0060] See you again Figure 1 Under light load conditions (i.e., low current region), the first switching element 10 (taking SiC-MOSFET as an example) has the following advantages: 1. Extremely low conduction loss: Due to the extremely low on-resistance of SiC-MOSFET, which changes only slightly with temperature rise, and the low current under light load conditions, the conduction loss ratio is even lower and the efficiency is higher; 2. Ultra-fast switching speed: SiC-MOSFET has a higher switching speed because its parasitic capacitance and charge are relatively low. In light load applications, high-frequency switching operation is often critical, and SiC-MOSFET can significantly reduce switching losses and EMI electromagnetic interference. Furthermore, its high switching speed makes it suitable for high-frequency operation, greatly improving light load efficiency; 3. No parasitic reverse recovery current: The body diode of SiC-MOSFET has extremely low reverse recovery current, which is almost negligible. In light load, high-frequency applications, the losses caused by the reverse recovery of the body diode are greatly reduced.

[0061] Under heavy load conditions (i.e., high current regions), the second switching element 20 (taking Si-IGBT as an example) has the following advantages: 1. Strong high current handling capability: Under heavy load conditions, its current capacity can reach hundreds of amperes or even higher, and it can stably handle high power requirements; 2. High withstand voltage capability: It is usually designed as a high withstand voltage switch, and the high withstand voltage range is usually beneficial to the needs of high voltage applications; 3. Good temperature stability: It has stable performance under heavy load and high temperature environments.

[0062] Therefore, the hybrid switching device of the present invention combines the advantages of the first switching element 10 and the second switching element 20. When the forward current is lower than the power operating point P, the first switching element 10 is used as the operating switch; when the forward current is higher than the power operating point P, the second switching element 20 is used as the operating switch.

[0063] The hybrid switching device of the present invention uses a combination of a first switching element 10 and a second switching element 20. See also... Figure 4A and Figure 4B The figures shown are circuit diagrams of the hybrid switching device 100 of the present invention used in parallel and circuit diagrams respectively. Figure 4AEquivalent circuit diagram of the hybrid switching device 100 used in parallel. The hybrid switching device used in parallel includes a first switching element 10, a second switching element 20, and a controller 50 (see attached diagram). Figure 5 The first switching element 10 can be independently controlled to be turned on or off. The second switching element 20 is connected in parallel with the first switching element 10, and the second switching element 20 can also be independently controlled to be turned on or off. The controller 50 is used to generate a control signal Sc, and controls the first switching element 10 and the second switching element 20 respectively according to the power operating point of the operating curve.

[0064] As mentioned above, please refer to the following: Figure 1 As shown, the operating curve refers to the operation under the power operating point P as the dividing line. When the forward current is below the power operating point P, the system operates under the first forward characteristic curve CV1, meaning that the control signal Sc of the controller 50 turns on the first switching element 10 and turns off the second switching element 20. Conversely, when the forward current is above the power operating point P, the system operates under the second forward characteristic curve CV2, meaning that the control signal Sc of the controller 50 turns on the second switching element 20 and turns off the first switching element 10. In other words, under light load conditions below the power operating point P, the control signal Sc turns on the first switching element 10 and turns off the second switching element 20; under heavy load conditions above the power operating point P, the control signal Sc turns on the second switching element 20 and turns off the first switching element 10, thereby optimizing the switching efficiency under mixed operation of the first switching element 10 and the second switching element 20.

[0065] Please see Figure 5 The diagram shown is a circuit diagram of a preferred embodiment of the hybrid switching device of the present invention. In this embodiment, the hybrid switching device 100 of the present invention is applied to a complete inverter bridge arm having an upper bridge arm BU and a lower bridge arm BL, wherein the switching architecture of the upper bridge arm BU is symmetrical to that of the lower bridge arm BL. In use, at least one first switching element 10 can be combined with at least one second switching element 20. Figure 5 Taking a preferred embodiment as an example, taking the upper bridge arm BU as an example, the number of second switching elements 20 is greater than the number of first switching elements 10, that is, the number of Si-IGBTs is greater than the number of SiC-MOSFETs. Further, as... Figure 5As shown, the ratio of the number of first switching elements 10 to the number of second switching elements 20 is 1:3. That is, when the number of first switching elements 10 in the upper bridge arm BU is one, the number of second switching elements 20 in the upper bridge arm BU is three, and so on. However, in different embodiments, the ratio of the number of first switching elements 10 to the number of second switching elements 20 can be 2:2. Therefore, when the number of first switching elements 10 in the upper bridge arm BU is two, the number of second switching elements 20 in the upper bridge arm BU is two, and so on. Similarly, for the switching architecture of the symmetrical lower bridge arm BL, when the number of first switching elements 10 in the lower bridge arm BL is two, the number of second switching elements 20 in the lower bridge arm BL is two, and so on.

[0066] Furthermore, based on the aforementioned operating principle according to the power operating point of the operating curve, under light load conditions below the power operating point, the first switching element 10 is controlled to turn on, that is, the first switching element 10 is controlled to turn on by the first control signal Sc1 in the control signal Sc generated by the controller 50. Conversely, under heavy load conditions above the power operating point, the second switching element 20 is controlled to turn on, that is, the second switching element 20 is controlled to turn on by the second control signal Sc2 in the control signal Sc generated by the controller 50. This optimizes the switching efficiency under mixed operation of the first switching element 10 and the second switching element 20.

[0067] Please see Figure 6 As shown, it is a waveform diagram of the forward characteristics of the first and second switching elements of the hybrid switching device of the present invention and the forward characteristics under hybrid drive. Figure 6 The aim is to illustrate the current distribution strategy of SiC-MOSFET and Si-IGBT. More specifically, the current distribution ratio is adjusted by controlling the forward voltage Vds of SiC-MOSFET and the forward voltage Vce of Si-IGBT, so that the system can operate at optimal power efficiency. Figure 6 The figures show the performance of a single SiC-MOSFET at 25°C and 175°C, the performance of a single Si-IGBT at 25°C and 175°C, and the performance of a combination of both at 25°C and 175°C.

[0068] First, a hybrid switching device with a single SiC-MOSFET and a single Si-IGBT is taken as an example for description. Assume that the total current is I_total, and the ratio of the current flowing through the SiC-MOSFET to the total current I_total is I_SiC_ratio, so the ratio of the current flowing through the Si-IGBT to the total current I_total is (1-I_SiC_ratio). Moreover, this current distribution ratio I_SiC_ratio is adjusted according to the forward voltage Vds and the forward voltage Vce. In an embodiment of the present invention, when Vds<Vt0, I_SiC_ratio=1, that is, all the current flows to the SiC-MOSFET, in other words, the current flowing to the SiC-MOSFET is I_total, and the current flowing to the Si-IGBT is 0. Herein, as Figure 6 the Vt0 shown is the threshold voltage of the Si-IGBT.

[0069] When Vds<Vce, 1>I_SiC_ratio>0.5, so the current flowing through the SiC-MOSFET is greater than the current flowing through the Si-IGBT. When Vds=Vce, I_SiC_ratio=0.5, so the current flowing through the SiC-MOSFET is equal to the current flowing through the Si-IGBT, that is, the SiC-MOSFET and the Si-IGBT share current equally. When Vds>Vce, 0.5>I_SiC_ratio>0, so the current flowing through the Si-IGBT is greater than the current flowing through the SiC-MOSFET.

[0070] Therefore, the current distribution ratio between the SiC-MOSFET and the Si-IGBT is controlled according to Vgs of the SiC-MOSFET and the relative magnitude between Vt0 or forward voltage Vce at the operating temperature of the Si-IGBT and Vgs, and then the optimal efficiency is achieved by controlling the current distribution ratio of the SiC-MOSFET and the Si-IGBT.

[0071] It is worth mentioning that Figure 6 the temperature shown refers to the operating temperature of the chip, for example, the forward characteristics of a single Si-IGBT, a single SiC-MOSFET and a hybrid switching device at an operating temperature of 25 degrees Celsius, or the forward characteristics of a single Si-IGBT, a single SiC-MOSFET and a hybrid switching device at an operating temperature of 175 degrees Celsius. In addition, due to the different characteristics of the SiC-MOSFET and the Si-IGBT, the operating temperatures of the two switching elements in hybrid operation are not necessarily the same, but the hybrid driving information can be found according to the forward characteristics at a specific temperature.

[0072] Furthermore, the onset voltage Vt0 of Si-IGBT varies at different temperatures. Moreover, the power operating point P (see [reference needed])... Figure 1 The positions where the forward voltage Vds equals the forward voltage Vce also differ.

[0073] Furthermore, the single and hybrid drive characteristics of the aforementioned switching element can satisfy both DC-to-AC and AC-to-DC applications. Moreover, although... Figure 6 The diagram shows the forward characteristics of the first and second switching elements and the forward characteristics under hybrid drive. However, the same principles apply to the reverse characteristics of the first and second switching elements and the reverse characteristics under hybrid drive.

[0074] Furthermore, when the ratio of SiC-MOSFETs to Si-IGBTs is 1:N, where N is a positive integer greater than 1, the SiC-MOSFETs can be preferentially controlled to operate at their optimal power efficiency point, carrying only the portion of the total current. The remaining current is then borne by the Si-IGBTs. In other words, when multiple Si-IGBTs are connected in parallel, the current distribution ratio is adjusted based on the temperature conditions of each Si-IGBT to maintain the optimal power efficiency after the combination.

[0075] In summary, the present invention has the following features and advantages: The design strategy of combining SiC-MOSFET and Si-IGBT is designed to leverage the advantages of both under different operating conditions and to complement their shortcomings, thereby achieving the best performance and efficiency of the system using the hybrid switching device.

[0076] The above description is merely a detailed description and accompanying drawings of preferred embodiments of the present invention. However, the features of the present invention are not limited thereto and are not intended to limit the present invention. The entire scope of the present invention should be determined by the following claims. All embodiments that conform to the spirit of the claims of the present invention and similar variations thereof should be included in the scope of the present invention. Any variations or modifications that can be easily conceived by those skilled in the art within the field of the present invention can be covered by the following claims.

Claims

1. A hybrid switching device, comprising: The first switching element can be controlled independently; The second switching element is connected in parallel with the first switching element, and the second switching element can be controlled independently; as well as The controller generates control signals and controls the first switching element and the second switching element respectively according to the power operating point of the operating curve; Specifically, when the forward characteristics of the first and second switching elements are below the power operating point, under the same forward voltage, the forward current of the first switching element is higher than that of the second switching element; when the power operating point is above the power operating point, under the same forward voltage, the forward current of the first switching element is lower than that of the second switching element; under light load conditions below the power operating point, the control signal controls the first switching element to turn on; under heavy load conditions above the power operating point, the control signal controls the second switching element to turn on, thereby optimizing the switching efficiency under mixed operation of the first and second switching elements.

2. The hybrid switching device according to claim 1, wherein under the light load condition below the power operating point, the control signal controls the second switching element to turn off; and under the heavy load condition above the power operating point, the control signal controls the first switching element to turn off.

3. The hybrid switching device according to claim 1, wherein under light load conditions below the power operating point, the operating curve is a first forward characteristic curve of the first switching element; and under heavy load conditions above the power operating point, the operating curve is a second forward characteristic curve of the second switching element.

4. The hybrid switching device according to claim 1, wherein the first switching element is a metal-oxide-semiconductor field-effect transistor and the second switching element is an insulated-gate bipolar transistor.

5. The hybrid switching device according to claim 4, wherein the metal oxide semiconductor field-effect transistor is a silicon carbide-based metal oxide semiconductor field-effect transistor, and the insulated gate bipolar transistor is a silicon-based insulated gate bipolar transistor.

6. The hybrid switching device according to claim 5, wherein the silicon carbide-based metal-oxide-semiconductor field-effect transistor comprises: First switch; A first resistor is connected in series with the first switch to form a first series path; Second resistor; as well as The first diode is connected in series with the second resistor to form a second series path; The first serial path is connected in parallel to the second serial path.

7. The hybrid switching device according to claim 5, wherein the silicon-based insulated gate bipolar transistor comprises: Second switch; The second diode is connected in series with the second switch; The third resistor is connected in series with the second diode to form a third series path; Fourth resistor; as well as The third diode is connected in series with the fourth resistor to form a fourth series path; The third series path is connected in parallel to the fourth series path.

8. The hybrid switching device according to claim 1, wherein the number of the second switching elements is greater than the number of the first switching elements.

9. The hybrid switching device according to claim 8, wherein the ratio of the number of the first switching elements to the number of the second switching elements is 1:

3.

10. The hybrid switching device according to claim 8, wherein the ratio of the number of the first switching elements to the number of the second switching elements is 2:

2.

11. The hybrid switching device according to claim 1, wherein the control signal includes a first control signal and a second control signal for controlling the first switching element and the second switching element respectively.

12. The hybrid switching device according to claim 5, wherein when the number of silicon carbide-based metal oxide semiconductor field-effect transistors and the number of silicon-based insulated-gate bipolar transistors are each one, the portion of the total current allocated to the silicon carbide-based metal oxide semiconductor field-effect transistors is I_total*I_SiC_ratio, and the portion of the total current allocated to the silicon-based insulated-gate bipolar transistors is I_total*(1-I_SiC_ratio); in, I_total represents the magnitude of the total current, and I_SiC_ratio represents the proportion of the total current allocated to the silicon carbide-based metal-oxide-semiconductor field-effect transistor.

13. The hybrid switching device according to claim 12, wherein I_SiC_ratio is 1 when the forward voltage of the silicon carbide-based metal-oxide-semiconductor field-effect transistor is less than the starting voltage of the silicon-based insulated-gate bipolar transistor; I_SiC_ratio is less than 1 and greater than 0.5 when the forward voltage of the silicon carbide-based metal-oxide-semiconductor field-effect transistor is less than the forward voltage of the silicon-based insulated-gate bipolar transistor; I_SiC_ratio is 0.5 when the forward voltage of the silicon carbide-based metal-oxide-semiconductor field-effect transistor is equal to the forward voltage of the silicon-based insulated-gate bipolar transistor; and I_SiC_ratio is less than 0.5 and greater than 0 when the forward voltage of the silicon carbide-based metal-oxide-semiconductor field-effect transistor is greater than the forward voltage of the silicon-based insulated-gate bipolar transistor.

14. The hybrid switching device according to claim 5, wherein the number of the silicon carbide-based metal oxide semiconductor field-effect transistor is one, and the number of the silicon-based insulated-gate bipolar transistor is N, where N is a positive integer greater than 1, wherein the silicon carbide-based metal oxide semiconductor field-effect transistor is controlled to operate at the optimal power efficiency point to flow through a portion of the total current, and the remaining N silicon-based insulated-gate bipolar transistors flow the remaining current.

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