An electronic system of discrete silicon carbide power devices

Abstract

The present invention discloses an electronic system for discrete silicon carbide power devices. The electronic system includes a control circuit, a drive circuit, and a power circuit. In order to achieve the smallest current loop for parallel discrete devices and reduce the impact of the power circuit on the drive circuit, the entire system is made into a separate power circuit board and a drive circuit board. The control circuit board, the drive circuit board, and the power circuit board are a three-layer structure, which can not only reduce the overall volume of the SiC motor controller, thereby enhancing the integration and power density of the SiC motor controller, but also achieve the purpose of reducing costs. In addition, the power circuit board of the electronic system uses a multi-group PCB laminated busbar structure design, which can not only enhance the current flow capacity of the power circuit board, but also reduce the stray inductance of the power circuit, avoid the power switching device from being subjected to large voltage overshoot during high-speed switching, thereby reducing power loss, improving system efficiency, and increasing system reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of motor controllers, and in particular to an electronic system of discrete silicon carbide power devices. Background Art

[0002] Motor controllers primarily consist of a power module, a power driver module, and a central control module. Power electronics are core components of motor controllers, determining the performance and cost of motor control systems. Discrete silicon carbide power devices (SiC MOSFETs) are widely used in high-power motor controller designs due to their high-temperature resistance, low loss, and suitability for high-frequency operation.

[0003] Currently, existing SiC motor controllers are primarily designed based on SiC MOSFET power modules. This power density is limited by existing SiC MOSFET modules, resulting in a larger overall size, lower integration, lower power density, and higher cost. Furthermore, due to module packaging limitations, the stray inductance of the SiC motor controller circuit is relatively high. SiC power devices switch quickly and are sensitive to circuit stray parameters. This high stray inductance causes the SiC MOSFET to experience significant voltage overshoot during high-speed switching, causing switching oscillations and generating additional power losses. This significantly increases the risk of device failure, ultimately impacting further improvements in motor controller efficiency, switching frequency, and reliability. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problems in the prior art of SiC motor controllers, such as large overall size, low integration, low power density and high cost, as well as large stray inductance that causes SiC MOSFET to undergo large voltage overshoot during high-speed switching, causing switching oscillation and ultimately affecting the efficiency, switching frequency and reliability of the motor controller.

[0005] According to a first aspect, an embodiment of the present invention provides an electronic system for discrete silicon carbide power devices, comprising: a control circuit board, a driver circuit board, and a power circuit board, which are layered and spaced apart within a cylindrical housing; wherein a parallel drive circuit is provided within the driver circuit board; a plurality of power switching devices within the parallel drive circuit are uniformly mounted on the inner wall of the cylindrical housing at preset intervals; power source electrodes and drain electrodes of the plurality of power switching devices are welded to the power circuit board; and Kelvin source electrodes and gate electrodes of the power switching devices are welded to the driver circuit board;

[0006] The multiple groups of PCB laminated busbars on the power circuit board are connected to the multiple power switching devices, and the multiple groups of PCB laminated busbars are also connected to the three-phase AC output end of the motor through copper columns. The control circuit in the control circuit board is used to control the operation of the motor.

[0007] By implementing the above-mentioned implementation method, the entire system is made into a separate power circuit board and driver circuit board. The control circuit board, driver circuit board and power circuit board are a three-layer structure, which can not only reduce the overall volume of the SiC motor controller, thereby enhancing the integration and power density of the SiC motor controller, but also achieve the purpose of reducing costs. In addition, the power circuit board of the electronic system uses a multi-group PCB laminated busbar structure design, which can not only enhance the current flow capacity of the power circuit board, but also reduce the stray inductance of the power circuit, avoid the power switching device from being subjected to a large voltage overshoot during high-speed switching, thereby reducing power loss and improving system efficiency. The symmetrical layout of the devices on the driver circuit board and the power circuit board can reduce the inconsistency of the stray inductance of the parallel devices, which is conducive to the realization of parallel current sharing of discrete devices and further increases the reliability of the system.

[0008] In combination with the first aspect, in one embodiment of the first aspect, a regular dodecagonal boss is processed on the inner wall of the cylindrical shell as a mounting surface for the power switching device, and the multiple power switching devices are fixed and heat is dissipated through the mounting surface.

[0009] By implementing the above embodiment, the contact area between the power switch device and the cylindrical housing can be increased, thereby improving the heat dissipation of the power switch device.

[0010] In combination with the first aspect, in another embodiment of the first aspect, the cylindrical shell is a heat sink made of aluminum material, and the drive circuit board, the power circuit board and the control circuit board are all arranged in a circular shape, wherein the diameters of the drive circuit board and the power circuit board are the same.

[0011] By implementing the above embodiment, the cylindrical housing is constructed as an aluminum heat sink, significantly enhancing the heat dissipation of multiple power switching devices. Furthermore, by arranging the control circuit board, driver circuit board, and power circuit board into identically sized circular shapes, the power density of each circuit board can be significantly increased, thereby enhancing the integration of the entire electronic system and ultimately improving its operating efficiency.

[0012] In combination with the first aspect, in another embodiment of the first aspect, the PCB laminated busbar includes: a negative busbar layer, a positive busbar layer, an AC current layer, a shielding layer and a signal layer, wherein a group of the PCB laminated busbars passes through the negative busbar layer, the AC current layer, and the positive busbar layer from top to bottom in a vertical direction, and are stacked in sequence to form multiple groups of busbar structures, and the positive busbar layer and the negative busbar layer in adjacent groups are adjacent.

[0013] By implementing the above implementation method, the power circuit board uses a large-area multi-group laminated busbar structure design, which can not only enhance the current flow capacity of the power circuit board, but also reduce the loop stray inductance and achieve parallel current sharing.

[0014] In combination with the first aspect, in another embodiment of the first aspect, the parallel driving circuit includes: a driving power supply, a driving chip, a push-pull amplifier circuit, and multiple power switch modules connected in parallel on a driving circuit board, the driving chip is connected to the driving power supply, the driving power supply is connected to each power switch module, the driving chip is also connected to the push-pull amplifier circuit, the push-pull amplifier circuit is connected to each power switch module through a driving resistor, and the output current of the push-pull amplifier circuit determines the parallel number of the power switch modules; each power switch module includes: interconnected power switching devices and a current sharing circuit, the current sharing circuit includes: a turn-on resistor, a first ferrite bead, a first rectifier diode, a turn-off resistor, and a second ferrite bead.

[0015] By executing the above embodiment, multiple power switch modules connected in parallel are connected through a driving power supply, a driving chip, and a push-pull amplifier circuit driving resistor, thereby driving the power switch device in each power switch module to operate, and the current sharing circuit in each power switch module can optimize the turn-on performance and turn-off performance of the SiC MOSFET tube, ultimately achieving dynamic current sharing and high efficiency. This can prevent individual power switch devices from experiencing overcurrent and excessive loss due to current imbalance in parallel devices, and can effectively protect each SiC MOSFET device, thereby improving system reliability and work efficiency.

[0016] In combination with the first aspect, in another embodiment of the first aspect, the turn-on resistor is connected to the push-pull amplifier circuit through the driving resistor, and the turn-on resistor is connected to the first ferrite bead to form a turn-on branch, and the first ferrite bead is connected to the gate of the power switching device; the first rectifier diode, the turn-off resistor, and the second ferrite bead are connected in sequence to form a turn-off branch, the turn-on branch is connected in parallel with the turn-off branch, and the second ferrite bead is connected to the gate of the power switching device.

[0017] By implementing the above embodiment, the turn-on performance and turn-off performance of the SiC MOSFET tube can be optimized, and ultimately dynamic current sharing and high efficiency can be achieved.

[0018] In combination with the first aspect, in another embodiment of the first aspect, each power switch module further includes: an anti-interference circuit, the anti-interference circuit being connected to the current sharing circuit and the power switch device;

[0019] The anti-interference circuit includes: a first capacitor, a transistor, a gate resistor, a second rectifier diode and a second capacitor;

[0020] The emitter of the transistor is connected to the gate of the power switch device through the first capacitor, the base of the transistor is connected to the Kelvin source of the power switch device through the source resistor, and the emitter of the transistor is also connected to the Kelvin source of the power switch device;

[0021] The gate resistor and the second rectifier diode are connected in series between the Kelvin source and the gate of the power switch device, and the second capacitor is connected in parallel between the Kelvin source and the gate of the power switch device.

[0022] By executing the above embodiment, the anti-interference capability of the circuit can be enhanced through the anti-interference circuit, thereby further achieving effective protection of the power switching device and improving the reliability of the system.

[0023] In combination with the first aspect, in another embodiment of the first aspect, the driving power supply forms a flyback topology structure through an isolated flyback converter, a power isolation transformer, a voltage regulating chip, a first regulating resistor and a second regulating resistor.

[0024] By implementing the above embodiment, the driving power supply adopts an extremely compact flyback topology structure, can output two isolated power supplies of +15V and -4V, and can stably output different negative voltages to adapt to different SiC MOSFET tubes. This prevents the risk of shoot-through to the opposite tubes when the SiC MOSFET tubes between the bridge arms are turned on when the power switching devices form a three-phase full-bridge structure, and can also reduce switching losses.

[0025] In combination with the first aspect, in another embodiment of the first aspect, the multiple power switching devices in the parallel drive circuit form a three-phase full-bridge structure, and the three-phase full-bridge structure is based on three groups of single-phase bridge structures, each group of single-phase bridge structures includes power switching devices and film capacitors connected in parallel in an upper bridge arm, and power switching devices and film capacitors connected in parallel in a lower bridge arm;

[0026] The power switching devices and the thin film capacitors connected in parallel between the upper and lower bridge arms of each group of single-phase bridge structures are connected to form an AC wiring point, which is the wiring midpoint between the upper bridge arm and the lower bridge arm. The AC wiring point of each group of single-phase bridge structures corresponds to a single-phase AC power connection of the motor.

[0027] By executing the above embodiment, the distance and impedance from the AC connection point to the upper and lower bridge arms parallel power switching devices can be equal, so the current has a minimum loop, and ultimately the inductance on the loop is small.

[0028] In combination with the first aspect, in another embodiment of the first aspect, the drain electrodes of the power switching devices in the upper bridge arms of each group of single-phase bridge structures connected in parallel are all connected to the positive bus layer, the power source electrodes of the power switching devices in the lower bridge arms of each group of single-phase bridge structures connected in parallel are all connected to the negative bus layer, and the power source electrodes of the power switching devices in the upper bridge arms of each group of single-phase bridge structures connected in parallel are connected to the drain electrodes of the power switching devices in the lower bridge arms of each group of single-phase bridge structures connected in parallel;

[0029] The first parallel ends of the film capacitors connected in parallel with the upper bridge arms of each group of single-phase bridge structures are connected to the positive bus layer, and the second parallel ends of the film capacitors connected in parallel with the upper bridge arms of each group of single-phase bridge structures are connected to the AC connection point of the group of single-phase bridge structures;

[0030] The first parallel ends of the thin film capacitors connected in parallel with each other in the lower bridge arms of each group of single-phase bridge structures are connected to the negative bus layer, and the second parallel ends of the thin film capacitors connected in parallel with each other in the lower bridge arms of each group of single-phase bridge structures are connected to the AC connection point of the group of single-phase bridge structures.

[0031] By implementing the above embodiment, the distance and impedance from the AC connection point to the parallel power switching devices in the upper and lower bridge arms are equal. Furthermore, by establishing an electrical connection between each set of laminated busbars, current flows from the positive busbar layer through the upper bridge arm capacitors to the AC current layer, and then through the lower bridge arm capacitors to the negative busbar layer, forming a minimal current loop and reducing the inductance of the loop. Therefore, through this connection, the current has a minimal loop, ultimately resulting in a low inductance loop.

[0032] In combination with the first aspect, in another embodiment of the first aspect, the control circuit includes: a central control chip, a sampling and conditioning circuit, a resolver circuit, a PWM drive circuit, a communication circuit, a protection circuit and a power supply circuit.

[0033] The sampling and conditioning circuit, the resolver circuit, the PWM drive circuit, the communication circuit, the protection circuit and the power supply circuit are all connected to the central control chip. The power supply circuit is also connected to the resolver circuit. The sampling and conditioning circuit is also connected to the protection circuit. The communication circuit is connected to an external host computer. The PWM drive circuit and the protection circuit are connected to the drive circuit board through wiring terminals.

[0034] By implementing the above embodiments, the operation of the motor can be controlled by the control circuit.

[0035] In combination with the first aspect, in another embodiment of the first aspect, the sampling and conditioning circuit includes: a current sampling sensor and a voltage sampling sensor, the current sampling sensor is located in the center of the power circuit board, and the voltage sampling sensor is located at the edge of the driver circuit board, and the voltage signal output by the voltage sampling sensor is transmitted to the control circuit board through the driver circuit board via a connector.

[0036] By implementing the above implementation, the layout rationality and power density of the system can be improved.

[0037] In combination with the first aspect, in another embodiment of the first aspect, the resolver circuit includes: a resolver decoding chip and an excitation signal amplification circuit;

[0038] The PWM driving circuit is used to convert the multiple PWM signals of the first voltage output by the central control chip into PWM signals of the second voltage;

[0039] The communication circuit is used for the central control chip to establish communication with the host computer;

[0040] The protection circuit is used to provide overvoltage protection for DC voltage, overcurrent protection for three-phase AC current, and fault protection for power switch devices of three bridge arms of a three-phase rectifier bridge.

[0041] By executing the above implementation, the electronic system can be assisted to operate normally, thereby assisting the central control chip to control the motor to operate reliably. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1Schematic diagram of the structure of the electronic system of the discrete silicon carbide power device in an embodiment of the present invention;

[0044] Figure 2A Schematic diagram of the laminated busbar structure in an embodiment of the present invention;

[0045] Figure 2B Schematic diagram of another laminated busbar structure in an embodiment of the present invention;

[0046] Figure 3 1 is a circuit schematic diagram of a parallel drive circuit for discrete silicon carbide power devices according to an embodiment of the present invention;

[0047] Figure 4 Schematic diagram of negative crosstalk protection of a power switch module in an embodiment of the present invention;

[0048] Figure 5 This is a schematic diagram of the driving power supply structure in an embodiment of the present invention;

[0049] Figure 6 This is a schematic diagram of a three-phase bridge structure formed by power switching devices in an embodiment of the present invention;

[0050] Figure 7 A schematic diagram of the connection of a thin film capacitor on a PCB power circuit board and a schematic diagram of the minimum current loop in an embodiment of the present invention;

[0051] Figure 8A is a top view of a power circuit board according to an embodiment of the present invention;

[0052] Figure 8B This is a top view wiring diagram of a power circuit board in an embodiment of the present invention;

[0053] Figure 9 Schematic diagram of a control circuit in a control circuit board according to an embodiment of the present invention;

[0054] Figure 10 A second-order voltage-controlled low-pass filter circuit in an embodiment of the present invention;

[0055] Figure 11 This is a schematic diagram of a hardware fast wave-enclosing circuit in an embodiment of the present invention;

[0056] 11- driving circuit board; 110- driving power supply; 111- driving chip;

[0057] 112-push-pull amplifier circuit; 113-power switch module; 114-driving resistor;

[0058] 1130-power switching device; 1131-current sharing circuit; 1132-anti-interference circuit;

[0059] 41-control circuit board; 42-drive circuit board; 43-power circuit board;

[0060] 44-motor; 410-control circuit; 4101-central control chip;

[0061] 4102-sampling and conditioning circuit; 4103-resolver circuit; 4104-PWM drive circuit;

[0062] 4105-communication circuit; 4106-protection circuit; 4107-power supply circuit. DETAILED DESCRIPTION

[0063] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0064] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0065] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components; wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0066] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0067] An embodiment of the present invention provides an electronic system of a discrete silicon carbide power device, which is also called an inverter. The electronic system is connected to a motor through a DC voltage input and an AC voltage output to drive the motor to rotate.

[0068] like Figure 1The electronic system for a discrete silicon carbide power device, shown in FIG. , includes a control circuit board 41, a driver circuit board 42, and a power circuit board 43, arranged in layers and intervals within a cylindrical housing. The driver circuit board 42 includes a parallel drive circuit. Multiple power switching devices 1130 in the parallel drive circuit are evenly mounted on the inner wall of the cylindrical housing at preset intervals. The power sources and drains of the multiple power switching devices are soldered to the power circuit board 43, while the Kelvin sources and gates of the power switching devices 1130 are soldered to the driver circuit board 42. The power circuit board connects the multiple power switching devices 1130 using multiple sets of PCB stacked busbars. These multiple sets of PCB stacked busbars are also connected to the three-phase AC output terminals of the motor via copper pillars. The control circuit in the control circuit board is used to control the operation of the motor. The motor is a resolver motor.

[0069] The electronic system of the discrete silicon carbide power device in the embodiment of the present invention features a control circuit board, a driver circuit board, and a power circuit board arranged in layers and intervals. This means the driver circuit board is separated from the power circuit board, minimizing the current loop and reducing the impact of the power circuit on the drive circuit. Furthermore, the Kelvin pins (TO2474 pins) of the SiC MOSFET T tube separate the power circuit from the drive circuit in terms of current flow. The gate G and Kelvin source S1 pins are soldered to the driver circuit board, while the power source S2 and drain D pins are soldered to the power circuit board. This not only helps prevent interference caused by high-side di / dt feedback on the gate voltage and reduces dynamic losses, but also facilitates a symmetrical layout of the power and drive circuits of parallel SiC MOSFETs. Furthermore, the driver circuit board employs the parallel drive circuit described in the above embodiment, further enhancing parallel current sharing. On the power circuit board, a design based on multiple PCB stacked busbars not only reduces coupling capacitance and stray inductance in the power circuit, but also achieves symmetry in the power circuits of the parallel power switching devices.

[0070] In addition, the electronic system of the discrete silicon carbide power device in the embodiment of the present invention includes a control circuit, a drive circuit and a power circuit. In order to achieve the smallest current loop of the parallel discrete devices and reduce the impact of the power circuit on the drive circuit, the entire system is made into a separate power circuit board and a drive circuit board. The control circuit board, the drive circuit board and the power circuit board are a three-layer structure, which can not only reduce the overall volume of the SiC motor controller, thereby enhancing the integration and power density of the SiC motor controller, but also achieve the purpose of reducing costs.

[0071] In a preferred embodiment, a regular dodecagonal boss is machined on the inner wall of the cylindrical housing to serve as a mounting surface for the power switching devices. This mounting surface secures multiple power switching devices and dissipates heat. The cylindrical housing is a heat sink made of aluminum, and the control circuit board, driver circuit board, and power circuit board are all arranged in the same circular shape.

[0072] By machining a regular dodecagonal boss from a cylindrical shell with a diameter of 90 mm, and using a ceramic insulating sheet on the mounting surface, multiple power switching devices (SiC MOSFETs) are mounted through the ceramic insulating sheet, and the cylindrical shell is a heat sink made of aluminum material, the heat dissipation of multiple power switching devices can be significantly enhanced. The driver circuit board, power circuit board, and control circuit board are all arranged in a circular shape with the same diameter, divided into an upper and lower three-layer structure, which can enhance the integration of the entire electronic system and ultimately improve the efficiency of the electronic system. In order to achieve high power density of the electronic system, the control circuit, driver circuit, and power circuit of the entire system are all implemented on a circular PCB with a diameter of 7 cm.

[0073] In another preferred embodiment, Figure 2A As shown in Figure 2B, in the electronic system of the discrete silicon carbide power device in the embodiment of the present invention, each group of PCB laminated busbars includes: a negative busbar layer, a positive busbar layer, an AC current layer, a shielding layer and a signal layer. Among them, each group of PCB laminated busbars passes through the negative busbar layer, the AC current layer, and the positive busbar layer from top to bottom in the vertical direction, and is stacked in sequence to form multiple groups of busbar structures. The positive busbar layer and the negative busbar layer in adjacent groups are adjacent.

[0074] Due to the fast switching speed of SiC MOSFETs, they are sensitive to circuit stray parameters. Large stray inductance causes SiC MOSFETs to experience large voltage overshoots during high-speed switching (high di / dt and du / dt), which can cause switching oscillations. Therefore, power circuit boards use a large, multi-stack busbar structure. This not only enhances the current flow capacity of the power circuit board, but also reduces circuit stray inductance, achieving parallel current sharing.

[0075] The laminated busbar structure is stacked vertically from top to bottom through the negative busbar layer, AC current layer, and positive busbar layer to form multiple busbar structures, which can realize a vertical multi-loop layout. The more busbar structures, the more loops, the smaller the overall impedance of the loop, and the smaller the inductance. In each set of laminated busbars, the current passes from the positive busbar layer through Figure 6 The upper bridge arm capacitor reaches the AC current layer and then passes through Figure 6The lower bridge arm capacitor reaches the negative bus layer, forming a minimum current loop, reducing the inductance value on the loop, effectively reducing the stray inductance of the entire electronic system loop to less than 10nH, effectively reducing the turn-off voltage spike of the parallel SiC MOSFET tube, and improving the conversion efficiency of the entire electronic system and reducing losses. Figure 2A Or as shown in 2B, it is a schematic diagram of the minimum current loop in the vertical direction.

[0076] The parallel drive circuit in the embodiment of the present invention is as follows: Figure 3 As shown, it includes: a driving power supply 110, a driving chip 111, a push-pull amplifier circuit 112, and a plurality of power switch modules 113 connected in parallel on a driving circuit board 11, the driving chip 111 is connected to the driving power supply 110, the driving power supply 110 is connected to each power switch module 113, the driving chip 111 is also connected to the push-pull amplifier circuit 112, the push-pull amplifier circuit 112 is connected to each power switch module 113 through a driving resistor 114, and the number of power switch modules 113 is determined based on the output current of the push-pull amplifier circuit 112; each power switch module 113 includes: each power switch module 113 includes: a power switch device 1130 and a current sharing circuit 1131 connected to each other, Figure 3 The current sharing circuit 1131 includes: a turn-on resistor R g1 、First ferrite bead L g1 , the first rectifier diode D1, the turn-off resistor R g2 , the second ferrite bead L g2 Among them, the turn-on resistance R g1 By driving the resistor 114 (R G ) is connected to the push-pull amplifier circuit 112 and the resistor R is turned on. g1 Connect the first ferrite bead L g1 Forming an open branch, the first ferrite bead L g1 Connected to the gate of the power switch device 1130; the first rectifier diode D1, the turn-off resistor R g2 , the second ferrite bead L g2 Connect in sequence to form a shutdown branch, open the branch in parallel with the shutdown branch, and the second ferrite bead L g2 Connect the gate of the power switch device 1130.

[0077] In another specific embodiment, Figure 3 In the embodiment, each power switch module 113 further includes an anti-interference circuit 1132, which is connected to the current sharing circuit 1131 and the power switch device 1130. The anti-interference circuit includes a first capacitor C1, a transistor Q3, a gate resistor R1, a second rectifier diode D2, and a second capacitor C g1Another anti-interference circuit includes a first capacitor C2, a transistor Q4, a gate resistor R2, a second rectifier diode D4 and a second capacitor C g2 .

[0078] exist Figure 3 In the embodiment, the emitter of transistor Q3 is connected to the gate of power switch device 1130 through first capacitor C1, and the base of transistor Q3 is connected to the gate of power switch device 1130 through source resistor R e1 The emitter of transistor Q3 is also connected to the Kelvin source of power switch device 1130; a gate resistor R1, a second rectifier diode D2, and a second capacitor C are connected in series between the Kelvin source and gate of power switch device 1130. g1 Connected in parallel between the Kelvin source and gate of the power switch device 1130.

[0079] exist Figure 3 In the example, the on-resistance R of the current sharing circuit 1131 is g1 and the off resistance R g2 , which is conducive to individually adjusting the steepness of the VDS pulse leading and trailing edges of each SiC MOSFET tube, so that the turn-on current peak and turn-off voltage spike of each SiC MOSFET can be individually optimized.

[0080] In addition, the on-resistance R of each SiC MOSFET tube g1 Then the first ferrite bead L is connected in series g1 , the off resistance of each SiCMOSFET tube R g2 Then the second ferrite bead L is connected in series g2 The first ferrite bead L g1 With the second ferrite bead L g2 Preferably, it is a ferrite bead. The first ferrite bead L g1 With the second ferrite bead L g2 The value of can be different.

[0081] The on-resistance R of each SiC MOSFET tube g1 With the off resistance R g2 Ferrite beads are connected in series behind each SiC MOSFET to achieve the goal of suppressing the amplitude of high-frequency oscillations caused by different parasitic parameters in the turn-on and turn-off circuits of each SiC MOSFET tube when the same drive power is applied to each SiC MOSFET tube, thereby ensuring dynamic current sharing of the power switching device (SiC MOSFET tube) and reducing the switching losses of each SiC MOSFET tube due to high-frequency oscillation. Ferrite beads with different selection values are used in the turn-on branch and the turn-off branch to increase the flexibility of the selection value and to reduce the loss of a single bead.

[0082] exist Figure 3 In the embodiment, another current sharing circuit 1131 includes: a turn-on resistor R g3 、First ferrite bead L g3 , the first rectifier diode D3, the turn-off resistor R g4 , the second ferrite bead L g4 Among them, the open resistor Rg3 drives the resistor 114 (R G ) is connected to the push-pull amplifier circuit 112 and the resistor R is turned on. g3 Connect the first ferrite bead L g3 Forming an open branch, the first ferrite bead L g3 Connected to the gate of the power switch device 1130; the first rectifier diode D3, the turn-off resistor R g4 , the second ferrite bead L g4 Connect in sequence to form a shutdown branch, open the branch in parallel with the shutdown branch, and the second ferrite bead L g4 Connecting to the gate of the power switch device 1130;

[0083] The emitter of transistor Q4 is connected to the gate of power switch device 1130 through first capacitor C2, and the base of transistor Q4 is connected to the gate of power switch device 1130 through source resistor R e2 The emitter of transistor Q4 is also connected to the Kelvin source of power switch device 1130; a gate resistor R2, a second rectifier diode D4, and a second capacitor C are connected in series between the Kelvin source and gate of power switch device 1130. g2 Connected in parallel between the Kelvin source and gate of the power switch device 1130.

[0084] exist Figure 3 In order to achieve parallel current sharing, the power switch devices 1130 (SiC MOSFET tubes) in the two parallel power switch modules share a driver chip 111 and a push-pull amplifier circuit 112. In addition to sharing a gate drive resistor 114 (RG), each SiC MOSFET tube has its own independent turn-on resistor R g1 With the off resistance R g2 , so that the gate voltage of each SiC MOSFET tube can rise and fall independently, ensuring that the gate threshold voltage of each SiC MOSFET tube can be switched simultaneously even if there are differences.

[0085] A source resistor R is added to the Kelvin source of each SiC MOSFET tube. g1 , the source resistor R g1 The resistance value can be 1R, the source resistance R g1 is conducive to eliminating the loop current formed by the difference in source inductance of the parallel SiC MOSFET tubes, and can form a benign negative feedback, reducing the switching speed of the faster-switching SiC MOSFET tubes and increasing the switching speed of the slower-switching SiC MOSFET tubes, so that the circuit operation is balanced. In addition, a series circuit of a transistor Q3 and a first capacitor C1 is added to the gate of each SiC MOSFET tube, and the Kelvin source resistor R g1 It can reduce the negative crosstalk generated when each SiC MOSFET is turned off. Figure 4 As shown in Figure 2, when each SiC MOSFET is turned off, the coupling current flows from the Kelvin source to the Kelvin source resistor R g1 , turning on the transistor Q3, and connecting the second capacitor C2 in series to the gate GS, forming a low-impedance channel for the coupling current, reducing negative crosstalk, and preventing the SiC MOSFET gate from being subjected to a larger negative voltage due to negative crosstalk, which may damage the gate insulation layer.

[0086] A series circuit consisting of a gate resistor R1 and a second rectifier diode D2 is added to the gate GS of each SiC MOSFET tube to increase the anti-interference capability of the driving gate.

[0087] exist Figure 3 In the embodiment, the number of power switch modules 113 is 2. In another optional embodiment, the number of power switch modules mentioned above can also be 3 or 4 or more. Because multiple power switch modules are connected in parallel to form a discrete structure, and each power switch module includes a power switch device and a current sharing circuit and an anti-interference circuit connected to each other, the power switch devices in the multiple power switch modules are also connected in parallel. The power switch modules connected in parallel can effectively improve the system current level.

[0088] In a preferred embodiment, the power switching device in the embodiment of the present invention is a silicon carbide power device. The silicon carbide power device is a SiC MOSFET tube. This is because silicon carbide power devices (SiC MOSFET tubes) have the characteristics of high temperature resistance, low loss, and suitability for high-frequency operation.

[0089] The embodiment of the present invention drives the power switch devices in each power switch module to operate by connecting a plurality of power switch modules in parallel through a driving power supply, a driving chip, and a push-pull amplifier circuit driving resistor. In addition, the current sharing circuit in each power switch module can optimize the turn-on and turn-off performance of the SiC MOSFET tube, ultimately achieving dynamic current sharing and high efficiency. This can avoid overcurrent and excessive loss that may cause damage to individual power switch devices due to current imbalance of parallel devices, and can effectively protect each SiC MOSFET device, thereby improving system reliability and work efficiency.

[0090] In another specific implementation manner, the parallel drive circuit in the embodiment of the present invention, Figure 3 It also includes: multiple film capacitors C connected in parallel 61 -C 64 Multiple thin-film capacitors connected in parallel are connected between the drain and Kelvin source of each power switch. Connecting multiple thin-film capacitors in parallel between the Ds of each SiC MOSFET helps absorb the voltage spike generated when the SiC MOSFET turns off. Multiple thin-film capacitors can be connected in parallel with a string of small-package, high-voltage ceramic capacitors, further absorbing the voltage spike generated when the SiC MOSFET turns off.

[0091] In another specific embodiment, Figure 5 As shown, the driver power supply forms a flyback topology through an isolated flyback converter U2, a power isolation transformer T1, a voltage regulator chip U3, a first regulating resistor R1, and a second regulating resistor R2. The isolated flyback converter U2 is connected to the primary winding of the power isolation transformer T1. The voltage regulator chip U3, the first regulating resistor R1, and the second regulating resistor R1 are connected to the secondary winding of the power isolation transformer T1. The secondary winding of the power isolation transformer T1 is connected to the driver chip and each power switch module.

[0092] Specifically, in Figure 5 In the figure, the first end of the primary winding of the power isolation transformer T1 is used to be connected to the positive input terminal of the system input power supply, the second end of the primary winding of the power isolation transformer T1 is connected to the isolated flyback converter U2, the first end of the secondary winding of the power isolation transformer T1 is connected to VCC through the rectifier diode D21, the second end of the secondary winding of the power isolation transformer T1 is connected to the voltage regulation chip U3 through the rectifier diode D22, the center tap of the power isolation transformer T1 is connected to the first regulation resistor R1, the first regulation resistor R1 is connected in parallel with the second regulation resistor R2, the voltage regulation chip U3 is connected to both ends of the second regulation resistor R2, and capacitors C8 and C9 are also connected in parallel to both ends of the second regulation resistor R2. Capacitors C5 and C6 are connected in series between the two rectifier diodes D21 and D22.

[0093] exist Figure 5 middle,

[0094] Specifically, in Figure 5 The driver power supply utilizes an extremely compact flyback topology, capable of outputting two isolated power supplies: +15V and -4V. To accommodate different SiC MOSFETs, the negative voltage output is connected to a voltage regulator chip (U3), model LM337. The resistance values of the first and second regulating resistors (R1 and R2) stabilize the output at varying negative voltages. These varying negative voltages prevent shoot-through when the SiC MOSFETs in the bridge legs of a three-phase full-bridge power switching device are switched on, thereby reducing switching losses. The primary side of the power isolation transformer T1 utilizes an isolated flyback converter (U2), model LT8302. This output voltage is isolated by directly sampling the primary-side flyback waveform, eliminating the need for a third winding or opto-isolator for regulation. The power isolation transformer T1 utilizes a low coupling capacitance design, with an inter-winding capacitance of only 7pF, which ensures high common-mode transient immunity, accommodating the fast switching of SiC MOSFETs.

[0095] In another specific embodiment, Figure 3 In the embodiment, the push-pull amplifier circuit 112 includes a first power driver device Q1 and a second power driver device Q2 connected to each other. The first power driver device Q1 and the second power driver device Q2 are further connected to a driver chip 111 ( U1 ) and a driver power supply 110 .

[0096] exist Figure 3 In the embodiment, the push-pull amplifier circuit 112 can realize the driving current required by the power switch device (SiC MOSFET tube) in parallel by selecting P MOSFET tubes and N MOSFET tubes with different current levels.

[0097] exist Figure 3 Driver chip 111 (U1) is a galvanically isolated, dual-channel SiC MOSFET driver that provides two completely independent drive outputs. Data transmission is achieved through integrated coreless transformer technology. Therefore, if multiple power switching devices form a three-phase bridge structure, a single driver chip can drive the SiC MOSFETs in one bridge arm, facilitating miniaturization of the driver circuit board.

[0098] In another specific embodiment, the driving circuit board is circular, and the diameter of the circle is determined based on the number of power switch modules.

[0099] The driver circuit board can be a PCB circuit board. Setting the driver circuit board in a circular shape is conducive to the symmetrical layout of discrete components, and can also make full use of the area of the driver circuit board, thereby improving the integration of the driver circuit board and achieving high power density.

[0100] Since the number of power switch modules is determined based on the output current of the push-pull amplifier circuit, that is, the greater the output current of the push-pull amplifier circuit, the greater the number of multiple power switch modules connected in parallel, and the greater the number of multiple power switch modules connected in parallel, the larger the diameter of the circular driver circuit board.

[0101] In another specific embodiment, on the driver circuit board, the push-pull amplifier circuit is arranged in the middle of multiple power switch modules, and the multiple power switch modules are arranged symmetrically based on the driver chip and the push-pull amplifier circuit, and the connection lines on the driver circuit board are arranged with the shortest distance.

[0102] For example, if the number of power switch modules is two, then the number of power switch devices is also two. Placing the push-pull amplifier circuit between the gate pins of two SiC MOSFET tubes not only achieves parallel current sharing, but also keeps the wiring as short as possible, reducing parasitic coupling capacitance and inductance.

[0103] Therefore, in the parallel drive circuit of the discrete silicon carbide power device in the embodiment of the present invention, multiple parallel power switch modules are arranged on a circular drive circuit board to share a driver chip and a push-pull amplifier circuit, thereby driving the power switch devices in each power switch module to work. In addition, each power switch module contains a current sharing circuit and an anti-interference circuit, which can not only optimize the turn-on and turn-off performance of the parallel SiC MOSFET tubes, but also ultimately achieve dynamic current sharing, avoid overcurrent and excessive loss of individual power switch devices due to current imbalance of parallel devices, and effectively protect each parallel SiC MOSFET device, thereby improving the reliability and working efficiency of the system.

[0104] In another specific embodiment, Figure 6 As shown, multiple power switching devices in the parallel drive circuit form a three-phase full-bridge structure. The three-phase full-bridge structure is based on three groups of single-phase bridge structures. Each group of single-phase bridge structures includes power switching devices and film capacitors connected in parallel in the upper bridge arm and power switching devices and film capacitors connected in parallel in the lower bridge arm.

[0105] The power switching devices and film capacitors connected in parallel between the upper and lower bridge arms of each single-phase bridge structure are connected to form an AC connection point. The AC connection point is the connection midpoint between the upper bridge arm and the lower bridge arm. The AC connection point of each single-phase bridge structure corresponds to one phase of AC power connected to the motor.

[0106] exist Figure 6In the embodiment, there are two power switching devices connected in parallel in the upper and lower bridge arms. If the number of power switching modules in the parallel drive circuit in the above embodiment is three, then there are three power switching devices connected in parallel in the upper and lower bridge arms. The power switching devices and film capacitors connected in parallel between the upper and lower bridge arms of each group of single-phase bridge structures are connected to form an AC wiring point. The AC wiring point is the wiring midpoint of the upper bridge arm and the lower bridge arm. The wiring midpoint is also the midpoint of the parallel capacitors on the power switching devices DS of the upper and lower bridge arms after being connected in series. The AC wiring point is used to carry three-phase AC power, which can achieve equal distances and impedances from the AC wiring point to the parallel power switching devices of the upper and lower bridge arms, thereby achieving the effect of current sharing. This design structurally guarantees the static and dynamic current sharing effects of parallel connection.

[0107] In another specific embodiment, Figure 6 In each group of single-phase bridge structures, the drains of the power switching devices connected in parallel in the upper bridge arms are all connected to the positive busbar layer, the power sources of the power switching devices connected in parallel in the lower bridge arms of each group of single-phase bridge structures are all connected to the negative busbar layer, and the power sources of the power switching devices connected in parallel in the upper bridge arms of each group of single-phase bridge structures are connected to the drains of the power switching devices connected in parallel in the lower bridge arms of each group of single-phase bridge structures. Figure 6 In each group of single-phase bridge structures, the first parallel ends of the film capacitors connected in parallel with each other in the upper bridge arms are connected to the positive busbar layer, and the second parallel ends of the film capacitors connected in parallel with each other in the upper bridge arms are connected to the AC connection point of the group of single-phase bridge structures; the first parallel ends of the film capacitors connected in parallel with each other in the lower bridge arms of each single-phase bridge structure are connected to the negative busbar layer, and the second parallel ends of the film capacitors connected in parallel with each other in the lower bridge arms of each single-phase bridge structure are connected to the AC connection point of the group of single-phase bridge structures. Figure 7 The figure shows the connection of the upper and lower bridge arms parallel film capacitors in the PCB power circuit board and the schematic diagram of the minimum current loop. Figure 7 In the figure, the direction of the arrow indicates the direction of current flow after the two parallel film capacitors in the upper and lower bridge arms are connected in series. Since the power switching devices and film capacitors connected in parallel between the upper and lower bridge arms of each single-phase bridge structure are connected to form an AC wiring point, the distance and impedance from the AC wiring point to the parallel power switching devices of the upper and lower bridge arms are equal. Therefore, the current has a minimum loop, which ultimately makes the inductance in the loop smaller.

[0108] In another specific embodiment, Figure 2A Or in 2B, the shielding layer is used to connect to the ground, and the signal layer is used to carry the signals of the current sampling sensor. Figure 8A 8B is a top view of the power circuit board in the embodiment of the present invention; 8C is a top view of the wiring diagram of the power circuit board in the embodiment of the present invention.

[0109] In another specific embodiment, Figure 9As shown in the electronic system of the discrete silicon carbide power device in the embodiment of the present invention, the control circuit 410 includes: a central control chip 4101, a sampling and conditioning circuit 4102, a resolver circuit 4103, a PWM drive circuit 4104, a communication circuit 4105, a protection circuit 4106 and a power supply circuit 4107. The central control chip is a DSP chip. Figure 9 In the figure, the sampling and conditioning circuit 4102, the resolver circuit 4103, the PWM drive circuit 4104, the communication circuit 4105, the protection circuit 4106 and the power supply circuit 4107 are all connected to the central control chip 4101, the power supply circuit 4107 is also connected to the resolver circuit 4103, the sampling and conditioning circuit 4102 is also connected to the protection circuit 4106, and the communication circuit 4105, the PWM drive circuit 4104 and the protection circuit 4106 are connected to the drive circuit board through the wiring terminals.

[0110] In another specific embodiment, the sampling and conditioning circuit includes: a current sampling sensor and a voltage sampling sensor. The current sampling sensor is located in the center of the power circuit board, and the voltage sampling sensor is located at the edge of the driver circuit board. The voltage signal output by the voltage sampling sensor is transmitted to the control circuit board through the driver circuit board via a connector. There is only a voltage sampling filter circuit on the control circuit board. The current filter circuit and the voltage filter circuit on the main control board both use a second-order voltage-controlled voltage source low-pass filter, which can make the phase delay of the signal relatively small. The circuit is as follows: Figure 10 The figure shows a second-order voltage-controlled low-pass filter circuit. Figure 10 In the figure, the second-order voltage-controlled low-pass filter circuit is composed of a resistor R1, a resistor R2, a capacitor C2 and a comparator.

[0111] In another specific embodiment, the resolver circuit includes: a resolver decoding chip and an excitation signal amplification circuit; the excitation signal amplification circuit uses a power amplifier TCA0372DW, and the excitation signal is output by the resolver decoding chip to drive the resolver in the system load motor. The decoding chip is also used to convert the sine and cosine signals output by the resolver containing motor speed or rotor position information into speed values or position values and upload them to the central control chip (DSP control chip).

[0112] In another specific embodiment, the PWM drive circuit is used to convert multiple first voltage PWM signals output by the central control chip into second voltage PWM signals; for example: the PWM drive circuit is used to convert six 3.3V PWM signals output by the DSP control chip into six 5V PWM signals as the primary side input PWM signals of the driver chip.

[0113] The communication circuit establishes communication between the central control chip and the host computer. This circuit is a CAN communication circuit, which is used to establish communication between the DSP control chip and the host computer. This circuit can receive commands from the host computer, upload various status information of the electronic system, and is also used for program programming. To reduce the size of the main control board, the CAN transceiver uses the LTM2889HY isolated transceiver, which requires only a single power supply.

[0114] The protection circuit is used to provide overvoltage protection for DC voltage, overcurrent protection for three-phase AC current, and fault protection for the power switching devices of the three bridge arms of the three-phase rectifier bridge. In a specific example, the protection circuit mainly uses logic devices in conjunction with DSP to implement protection logic, including three-way AC current overcurrent protection, one-way DC voltage overvoltage protection, and three-way IGBT fault protection. Each signal that needs to be protected is first combined with the protection threshold voltage through a comparator to generate an overvoltage signal, and then multiple protection signals are synthesized through an AND gate. The final generated fault signal is latched by a latch built by the logic device, and the fault signal is transmitted to the enable pin of the PWM drive circuit to achieve wave blocking. This circuit can achieve fast hardware wave blocking, without the need to transmit the fault signal to the DSP for judgment and then perform the wave blocking operation, and can achieve efficient and fast protection for the electronic system. The principle block diagram of the hardware wave blocking circuit is as follows: Figure 11 shown.

[0115] The power supply circuit primarily converts an external 24V supply into the 5V, 3.3V, and 1.9V voltage signals required by the DSP control chip, as well as the 12V voltage signal required by the resolver decoder chip. The 5V and 12V voltage signals utilize isolated power supplies, while the 1.9V and 3.3V power supplies utilize LDO chips.

[0116] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. An electronic system of discrete silicon carbide power devices, characterized in that: include: A control circuit board, a driver circuit board, and a power circuit board are arranged in layers and intervals within a cylindrical housing, wherein the driver circuit board is provided with a parallel drive circuit, and multiple power switching devices in the parallel drive circuit are evenly mounted on the inner wall of the cylindrical housing at preset intervals, and the power source and drain electrodes of the multiple power switching devices are welded to the power circuit board, and the Kelvin source and gate electrodes of the power switching devices are welded to the driver circuit board; The power circuit board is connected to the multiple power switching devices based on multiple sets of PCB laminated busbars, and the multiple sets of PCB laminated busbars are also connected to the three-phase AC output end of the motor through copper pillars. The control circuit in the control circuit board is used to control the operation of the motor; The parallel drive circuit includes: a drive power supply, a drive chip, a push-pull amplifier circuit, and multiple power switch modules connected in parallel on a drive circuit board. The drive chip is connected to the drive power supply, and the drive power supply is connected to each power switch module. The drive chip is also connected to the push-pull amplifier circuit. The push-pull amplifier circuit is connected to each power switch module through a drive resistor. The number of power switch modules connected in parallel is determined based on the output current of the push-pull amplifier circuit. Each power switch module includes: interconnected power switch devices and a current sharing circuit. The current sharing circuit includes: a turn-on resistor, a first ferrite bead, a first rectifier diode, a turn-off resistor, and a second ferrite bead.

2. The electronic system of discrete silicon carbide power devices according to claim 1, characterized in that: A regular dodecagonal boss is processed on the inner wall of the cylindrical shell as a mounting surface of the power switch device, and the multiple power switch devices are fixed and heat is dissipated through the mounting surface.

3. The electronic system of discrete silicon carbide power devices according to claim 1 or 2, characterized in that: The cylindrical shell is a heat sink made of aluminum material. The driving circuit board, the power circuit board and the control circuit board are all arranged in a circular shape, wherein the driving circuit board, the power circuit board and the control circuit board have the same diameter.

4. The electronic system of discrete silicon carbide power devices according to claim 1, characterized in that: Each group of PCB laminated busbars includes: a negative busbar layer, a positive busbar layer, an AC current layer, a shielding layer, and a signal layer. Each group of PCB laminated busbars passes through the negative busbar layer, the AC current layer, and the positive busbar layer in a vertical direction from top to bottom, and is stacked in sequence to form multiple groups of busbar structures. The positive busbar layer and the negative busbar layer in adjacent groups are adjacent.

5. The electronic system of discrete silicon carbide power devices according to claim 1, characterized in that: The turn-on resistor is connected to the push-pull amplifier circuit through the driving resistor, and the turn-on resistor is connected to the first ferrite bead to form a turn-on branch, and the first ferrite bead is connected to the gate of the power switching device; the first rectifier diode, the turn-off resistor, and the second ferrite bead are connected in sequence to form a turn-off branch, the turn-on branch is connected in parallel with the turn-off branch, and the second ferrite bead is connected to the gate of the power switching device.

6. The electronic system of discrete silicon carbide power devices according to claim 1, characterized in that: Each power switch module further includes: an anti-interference circuit, wherein the anti-interference circuit is connected to the current sharing circuit and the power switch device; The anti-interference circuit includes: a first capacitor, a transistor, a gate resistor, a second rectifier diode and a second capacitor; The emitter of the transistor is connected to the gate of the power switch device through the first capacitor, the base of the transistor is connected to the Kelvin source of the power switch device through the source resistor, and the emitter of the transistor is also connected to the Kelvin source of the power switch device; The gate resistor and the second rectifier diode are connected in series between the Kelvin source and the gate of the power switch device, and the second capacitor is connected in parallel between the Kelvin source and the gate of the power switch device.

7. The electronic system of discrete silicon carbide power devices according to claim 1, characterized in that: The driving power supply forms a flyback topology structure through an isolated flyback converter, a power isolation transformer, a voltage regulating chip, a first regulating resistor and a second regulating resistor.

8. The electronic system of discrete silicon carbide power devices according to claim 4, characterized in that: The plurality of power switching devices in the parallel drive circuit form a three-phase full-bridge structure, each of which is based on three groups of single-phase bridge structures, each of which includes power switching devices and film capacitors connected in parallel in an upper bridge arm and power switching devices and film capacitors connected in parallel in a lower bridge arm; The power switching devices and the thin film capacitors connected in parallel between the upper and lower bridge arms of each group of single-phase bridge structures are connected to form an AC wiring point, which is the wiring midpoint between the upper bridge arm and the lower bridge arm. The AC wiring point of each group of single-phase bridge structures corresponds to a single-phase AC power connection of the motor.

9. The electronic system of discrete silicon carbide power devices according to claim 8, characterized in that: The drain electrodes of the power switching devices in the upper bridge arms of each group of single-phase bridge structures connected in parallel are all connected to the positive busbar layer, the power sources of the power switching devices in the lower bridge arms of each group of single-phase bridge structures connected in parallel are all connected to the negative busbar layer, and the power sources of the power switching devices in the upper bridge arms of each group of single-phase bridge structures connected in parallel are connected to the drain electrodes of the power switching devices in the lower bridge arms of each group of single-phase bridge structures connected in parallel; The first parallel ends of the film capacitors connected in parallel with the upper bridge arms of each group of single-phase bridge structures are connected to the positive bus layer, and the second parallel ends of the film capacitors connected in parallel with the upper bridge arms of each group of single-phase bridge structures are connected to the AC connection point of the group of single-phase bridge structures; The first parallel ends of the thin film capacitors connected in parallel with each other in the lower bridge arms of each group of single-phase bridge structures are connected to the negative bus layer, and the second parallel ends of the thin film capacitors connected in parallel with each other in the lower bridge arms of each group of single-phase bridge structures are connected to the AC connection point of the group of single-phase bridge structures.

10. The electronic system of discrete silicon carbide power devices according to claim 1, characterized in that: The control circuit includes: a central control chip, a sampling and conditioning circuit, a resolver circuit, a PWM drive circuit, a communication circuit, a protection circuit and a power supply circuit. The sampling and conditioning circuit, the resolver circuit, the PWM drive circuit, the communication circuit, the protection circuit and the power supply circuit are all connected to the central control chip. The power supply circuit is also connected to the resolver circuit. The sampling and conditioning circuit is also connected to the protection circuit. The communication circuit is connected to an external host computer. The PWM drive circuit and the protection circuit are connected to the drive circuit board through wiring terminals.

11. The electronic system of discrete silicon carbide power devices according to claim 10, characterized in that: The sampling and conditioning circuit includes: a current sampling sensor and a voltage sampling sensor. The current sampling sensor is located in the center of the power circuit board, and the voltage sampling sensor is located at the edge of the driver circuit board. The voltage signal output by the voltage sampling sensor is transmitted to the control circuit board through the driver circuit board via a connector.

12. The electronic system of discrete silicon carbide power devices according to claim 11, characterized in that: The resolver circuit includes: a resolver decoding chip and an excitation signal amplifying circuit; The PWM driving circuit is used to convert the multiple PWM signals of the first voltage output by the central control chip into PWM signals of the second voltage; The communication circuit is used for the central control chip to establish communication with the host computer; The protection circuit is used to provide overvoltage protection for DC voltage, overcurrent protection for three-phase AC current, and fault protection for power switch devices of three bridge arms of a three-phase rectifier bridge.

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