High-power inverter plate based on silicon carbide MOSFET on welding and cutting power supply

Abstract

The utility model relates to the technical field of inverter welding and cutting power supplies, and provides a silicon carbide MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor)-based high-power inverter plate on a welding and cutting power supply, which comprises a full-bridge inverter main loop module, a driving circuit module, a driving special power supply circuit module, an absorption circuit module, a driving power supply and a signal interface, the full-bridge inversion main loop module is electrically connected with the driving circuit module; and the full-bridge inversion main loop module and the driving circuit module are electrically connected with the absorption circuit module. According to the utility model, on the basis of a third-generation semiconductor device represented by silicon carbide, a high-power inverter plate is made and is applied to an inverter welding and cutting power supply, the power of the inverter plate is greatly improved by utilizing the advantages of the newest-generation silicon carbide MOSFET, meanwhile, the heating of an inverter is reduced, and the volume and the weight of the inverter welding and cutting power supply are integrally reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of inverter welding power supplies, in particular to a high-power inverter board based on silicon carbide MOSFET on a welding power supply. Background Art

[0002] The development of power semiconductor devices plays a decisive role in the development of power electronics technology and electrical equipment. According to the chronological order of research and large-scale application, the industry divides semiconductor materials into three generations. The first generation of semiconductors is semiconductor devices represented by silicon materials, the second generation of semiconductors is semiconductor devices represented by gallium arsenide, and the third generation of semiconductors is semiconductor devices represented by silicon carbide. As a representative of the third generation of wide bandgap semiconductor materials, silicon carbide has significant advantages in key parameters such as bandgap width, breakdown electric field, thermal conductivity, electron saturation rate, and radiation resistance. It meets the needs of modern industry for high power, high voltage, and high frequency, and is mainly used to make high-speed, high-frequency, high-power and light-emitting electronic components.

[0003] As a third-generation semiconductor material, silicon carbide has many significant advantages: (1) High-voltage resistance: Silicon carbide has a breakdown field strength more than 10 times that of silicon, so it can achieve a higher breakdown voltage through lower resistivity and thinner drift layer. Under the same withstand voltage value, the on-resistance / size of silicon carbide power devices is only 1 / 10 of that of silicon, and the power loss is greatly reduced. (2) High-frequency resistance: Silicon carbide materials do not have the current tailing phenomenon, which can increase the switching speed of components, which is 3-10 times the switching speed of silicon, making it suitable for higher frequencies and faster switching speeds. (3) High-temperature resistance: Silicon carbide materials have a large bandgap (about 3 times that of silicon), high thermal conductivity (about 3.3 times that of silicon), and a high melting point (2830°C, about twice that of silicon -1410°C). Therefore, silicon carbide devices can significantly increase the operating temperature while reducing current leakage.

[0004] At present, silicon carbide MOSFET devices based on silicon carbide materials have been widely used in new energy vehicles, photovoltaics, energy storage and other industries, but have not been used in the field of inverter welding power supplies. The core of inverter welding power supplies is the inverter link. At present, the inverter of domestic inverter welding power supplies still uses semiconductor devices based on silicon materials (silicon MOSFET, or IGBT). There is not much room for improvement in power output and inverter volume and weight. The power density of the inverter is very low. The latest generation of silicon carbide MOSFET has great advantages in power output and miniaturization of inverters. Utility Model Content

[0005] In view of the above shortcomings of the prior art, the utility model provides an inverter board on an inverter welding power supply, whose inverter core adopts silicon carbide MOSFET made of the latest material, which can effectively solve the problem of low power density of the existing inverter welding power supply.

[0006] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] The utility model discloses a high-power inverter board based on silicon carbide MOSFET on a welding power supply, which comprises a full-bridge inverter main circuit part, a drive circuit part, a drive-specific power circuit part, an absorption circuit part, a drive power supply and a signal interface.

[0008] The full-bridge inverter main circuit is a full-bridge inverter circuit composed of 4 silicon carbide MOSFETs. The positive pole of the input power DC power supply is connected to the drain of tubes 1 and 2, and the source of tube 1 is connected to the drain of tube 3. At the same time, its connection point is used as the inverter output AC 1, and the source of tube 2 is connected to the drain of tube 4. At the same time, its connection point is used as the inverter output AC 2, and the source of tube 2 and the source of tube 4 are connected to the negative pole of the input power DC power supply.

[0009] Furthermore, the package of the silicon carbide MOSFET is TO-247-4, which has a separate Kelvin source (driving source) that cooperates with the gate as the driving end input of the silicon carbide MOSFET.

[0010] The driving circuit adopts an independent 4-channel independent driving mode, each channel drives a silicon carbide MOSFET, and the driving circuit adopts an isolated chip driving form. The driving chip can be a clamping protection chip, or a chip with separate on and off control. The output end of the driving chip adopts a separate power supply. Due to the particularity of silicon carbide MOSFET, the power supply of the driving chip is a positive and negative asymmetric power supply. The output end of the chip is connected to one end of the on resistor and the off resistor respectively, and the other end of the on resistor and the off resistor is connected to the gate of the silicon carbide MOSFET. The Kelvin source (driving source) of the silicon carbide MOSFET is connected to the ground wire of the independent power supply. A parallel gate capacitor and a discharge resistor are connected between the gate and the Kelvin source (driving source), and two TVS tubes are connected in series in reverse phase and then connected in parallel between the gate and the Kelvin source as overvoltage protection for gate drive.

[0011] Furthermore, the input end of the driver chip is powered by a single 15V power supply, which is isolated from the output end and does not share a common ground. The drive signal input end is connected to one end of the PWM signal resistor, and the other end of the PWM signal resistor is connected to the control PWM signal. A filter capacitor is connected between the drive signal input end and the 15V ground line to play an anti-interference role.

[0012] The dedicated drive power supply circuit includes four separate DC-DC power supplies. The electrical circuit structure of each group is the same. The input is the input DC power of the drive power supply and signal interface. The output of each group is the positive and negative power supply with a common ground. The input and output are completely insulated. Each group works independently and provides independent power to the output end of the drive chip on the drive circuit.

[0013] The absorption circuit part is composed of absorption resistors and absorption capacitors, with a total of four groups, each with the same structure. One end of the absorption resistor is connected to one end of the absorption capacitor, the other end of the absorption resistor is connected to the drain of the silicon carbide MOSFET, and the other end of the absorption capacitor is connected to the source of the silicon carbide MOSFET. A set of absorption circuits is connected between the drain and source of each silicon carbide MOSFET.

[0014] The driving power supply and signal interface are connected to the peripheral control board to provide driving input power supply and driving switch logic signal to the silicon carbide MOSFET of the utility model.

[0015] Compared with the known public technology, the technical solution provided by the utility model has the following beneficial effects:

[0016] 1. The utility model provides an inverter board based on silicon carbide MOSFET devices, which can greatly improve power output and inverter frequency, while significantly reducing heat generation, effectively reducing the size of the inverter and improving the power density of the corresponding inverter.

[0017] 2. The utility model provides a high-power inverter board based on silicon carbide MOSFET, which adopts a chip driver with primary and secondary side isolation. The opening and closing can be adjusted separately, and the driving performance of silicon carbide MOSFET can be maximized.

[0018] 3. The utility model provides a high-power inverter board based on silicon carbide MOSFET. The power supply of the driver chip is an independent power supply, which reduces the interference between drivers. At the same time, each silicon carbide MOSFET on the main circuit of the inverter has a separate absorption circuit, which greatly improves the reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a discrete device packaging form of silicon carbide MOSFET;

[0021] Figure 2 This is the principle diagram of the high-power inverter board based on silicon carbide MOSFET of the utility model;

[0022] Figure 3 This is a PCB layout of a high-power inverter board based on silicon carbide MOSFET in the utility model;

[0023] Figure 4 Another PCB layout of the high-power inverter board based on silicon carbide MOSFET of the utility model;

[0024] The numbers in the figure represent: 1. Inverter main circuit; 2. Drive circuit; 3. Drive dedicated power supply circuit; 4. Absorption circuit; 5. Drive power supply and signal interface; Q1~Q4-first MOS tube~fourth MOS tube. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] The utility model is further described below in conjunction with embodiments.

[0027] A high-power inverter board based on silicon carbide MOSFET in this embodiment, such as Figure 2 As shown in the schematic diagram, it includes an inverter main circuit 1, a drive circuit 2, a drive-specific power supply circuit 3, an absorption circuit 4, and a drive power supply and signal interface 5.

[0028] The inverter main circuit is a full-bridge inverter circuit composed of four silicon carbide MOSFETs. The packaging form of silicon carbide MOSFET is as follows: Figure 1 As shown, it consists of 4 pins, including drain, source, Kelvin source (driving source), gate. The driving source is separated, which can effectively avoid driving crosstalk and make the operating frequency higher. At the same time, due to the characteristics of silicon carbide materials, the heat generation of silicon carbide MOSFET will be very low, which can effectively increase the output power of the inverter and reduce the size of the inverter.

[0029] like Figure 2In the schematic diagram shown, the inverter main circuit part (1) is composed of four silicon carbide MOSFETs Q1, Q2, Q3, and Q4. The drains of Q1 and Q2 are connected to the positive pole of the input DC bus, the source of Q1 is connected to the drain of Q3, and the connection point serves as the inverter output terminal 1. The source of Q2 is connected to the drain of Q4, and the connection point serves as the inverter output terminal 2. The sources of Q3 and Q4 are connected to the negative pole of the input DC bus.

[0030] like Figure 2 In the schematic diagram shown, the drive circuit part adopts an independent 4-channel independent drive mode, each channel drives a silicon carbide MOSFET, and the drive circuit adopts an isolated chip drive form. The drive chip can be a clamp protection chip, or a chip with separate on and off control. The output end of the drive chip adopts a separate power supply form. Due to the particularity of silicon carbide MOSFET, the power supply of the drive chip is a positive and negative asymmetric power supply. Taking one of the channels as an example, the output part of the isolated drive chip (U1) is pins 5 to 8, pin 8 is connected to the positive voltage of the independent drive power supply, pin 5 is connected to the negative voltage of the independent drive power supply, pin 7 is connected to one end of the turn-on resistor R2, pin 6 is connected to one end of the turn-off resistor R1, the other end of the turn-on resistor R2 and the other end of the turn-off resistor R1 are connected together, connected to the gate of the silicon carbide MOSFET (Q1), and the drive source of Q1 is connected to the ground line of the independent drive power supply. The anti-interference capacitor C1 and the bleeder resistor R3 are driven in parallel between the gate and the drive source of Q1. The cathode of TVS tube Z1 is connected to the gate of Q1, the anode of Z1 is connected to the anode of TVS tube Z2, and the anode of Z2 is connected to the driving source of Q1.

[0031] Furthermore, the input terminals 1 to 4 of the driver chip, pin 1 is connected to the positive pole of the single power supply 15V, pin 4 is connected to the ground line of the single power supply 15V, pin 2 is the positive terminal of the drive signal input, connected to one end of the PWM signal resistor R13, and the other end of the PWM signal resistor R13 is connected to the control PWM signal. Pin 3 is the negative terminal of the drive signal input, connected to the input signal ground line (the same ground as the power supply 15V), and a filter capacitor C5 is connected between pins 2 and 3 of the driver chip input terminal.

[0032] The circuit connection methods of the other three channels are the same and will not be described in detail.

[0033] Preferably, the driver chip may be a driver chip of the NSI6601B or 1EDI60N12AF model, or a chip with a Miller clamp function.

[0034] like Figure 2In the schematic diagram shown, the dedicated drive power circuit includes four separate DC-DC power supplies. The electrical circuit structure of each group is the same. The input is the input DC of the drive power supply and signal interface. The output of each group is the positive and negative power supply with a common ground. The input and output are completely insulated. Each group works independently and provides independent power to the output end of the driver chip on the drive circuit. Take one group as an example to introduce its specific wiring. U5 is a DC-DC power module, which can be a finished DC-DC module or a DC-DC component made of a switching power supply. The input of U5 is pins 1-2. Pin 1 is connected to the positive pole of the input 15V power supply, and pin 2 is connected to the negative pole of the input 15V power supply. A filter capacitor C10 is connected between pins 1-2. The output end of U5 is pins 5 to 7. Pin 5 is the negative pole of the isolated output negative power supply, pin 6 is the common ground of the isolated output power supply, and pin 7 is the positive pole of the output positive power supply. Filtering and stabilizing capacitors C11 and C12 are connected in parallel between pins 5 and 6, and filtering and stabilizing capacitors C13 and C14 are connected in parallel between pins 6 and 7. A filter capacitor C36 is connected in parallel between pins 5 and 7.

[0035] like Figure 2 In the schematic diagram shown, the absorption circuit module is composed of absorption resistors and absorption capacitors, with a total of four groups, each with the same structure. Take one group as an example: the absorption resistors RC1 and RC2 are connected in parallel, one end of which is connected to one end of the absorption capacitor CR1, the other end of the absorption resistor is connected to the source of the silicon carbide MOSFET (Q1), and the other end of the absorption capacitor CR1 is connected to the drain of the silicon carbide MOSFET (Q1). A set of absorption circuits is connected between the drain and source of each silicon carbide MOSFET.

[0036] Figure 3 This utility model is a PCB layout of a high-power inverter board based on silicon carbide MOSFET. Figure 2 The schematic diagram is shown in Figure 1. It is drawn on a PCB board based on the connection diagram, where CN2 and CN3 are the positive and negative poles of the external DC bus, Q1~Q4 are silicon carbide MOSFETs, and the drive circuit part, the drive dedicated power circuit part and the absorption circuit part are all distributed around the printed circuit board PCB. The advantage of this layout is that the volume of the inverter PCB can be made smaller and the power density is higher.

[0037] Figure 4This is another PCB layout of the high-power inverter board based on silicon carbide MSFET of the utility model. In terms of layout, the inverter main circuit part and the absorption circuit part are placed on one PCB board, and the drive circuit and the drive-specific power supply circuit part are placed on another PCB board. The two PCB printed boards are connected through a wiring harness plug strip. The advantage of this layout is that the drive and the main circuit can be separated, which can better avoid the interference problem of the drive part. At the same time, the power of the inverter main circuit part can be made larger under the same volume requirement.

[0038] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-power inverter board based on silicon carbide MOSFET for welding power supply, characterized in that: It includes a full-bridge inverter main circuit module, a drive circuit module, a drive-specific power circuit module, an absorption circuit module, a drive power supply and a signal interface; The full-bridge inverter main circuit module is electrically connected to the drive circuit module; The full-bridge inverter main circuit module and the drive circuit module are both electrically connected to the absorption circuit module; The dedicated driving power supply circuit module is electrically connected to the driving circuit module to provide power to the driving circuit module; The driving power supply and the signal interface are electrically connected to the driving dedicated power supply circuit module to input direct current to the driving dedicated power supply circuit module.

2. The high-power inverter board based on silicon carbide MOSFET on a welding power supply according to claim 1 is characterized in that: The full-bridge inverter main circuit module is a full-bridge inverter circuit composed of four silicon carbide MOSFETs, namely a first MOS tube, a second MOS tube, a third MOS tube and a fourth MOS tube. The drain of the first MOS tube and the drain of the second MOS tube are electrically connected to the positive electrode of the input power DC power supply, the source of the first MOS tube is electrically connected to the drain of the third MOS tube, and the connection point thereof serves as the first inverter output AC; the source of the second MOS tube is electrically connected to the drain of the fourth MOS tube, and the connection point thereof serves as the second inverter output AC; the source of the third MOS tube and the source of the fourth MOS tube are connected to the negative electrode of the input power DC power supply.

3. The high-power inverter board based on silicon carbide MOSFET on a welding power supply according to claim 2 is characterized in that: The silicon carbide MOSFET has a separate driving source electrode, which cooperates with the gate electrode as a driving terminal input of the silicon carbide MOSFET.

4. The high-power inverter board based on silicon carbide MOSFET on a welding power supply according to claim 1 is characterized in that: The drive circuit module adopts an independent 4-channel separate driving mode, each channel drives a silicon carbide MOSFET, and the drive circuit module is driven by an isolated drive chip; The driver chip is any one of a clamp protection chip or an on / off separate control chip, the output end of the driver chip adopts a separate power supply, and the power supply is a positive and negative asymmetric power supply; The output end of the driving chip is respectively connected to one end of the on-resistance and the off-resistance, the other end of the on-resistance and the off-resistance is connected to the gate of the silicon carbide MOSFET, and the driving source of the silicon carbide MOSFET is connected to the ground wire of the independent power supply; A gate capacitor and a discharge resistor are connected in parallel between the gate of the silicon carbide MOSFET and its driving source, and a TVS tube is connected in parallel between the gate of the silicon carbide MOSFET and its driving source. Two TVS tubes are provided and the two are connected in anti-phase series as overvoltage protection for gate drive.

5. The high-power inverter board based on silicon carbide MOSFET on a welding power supply according to claim 1 is characterized in that: The dedicated drive power supply circuit module includes four groups of separate DC-DC power supplies. The electrical circuit structure of each group of power supplies is the same, and its input is the input DC power of the drive power supply and signal interface. The output of each group of power supplies is a positive and negative power supply with a common ground. The power supply input and output are completely insulated, and each group works independently to provide independent power to the output end of the drive chip on the drive circuit module.

6. The high-power inverter board based on silicon carbide MOSFET on a welding power supply according to claim 1, characterized in that: The absorption circuit module includes an absorption resistor and an absorption capacitor, one end of the absorption resistor is connected to one end of the absorption capacitor, the other end of the absorption resistor is connected to the drain of the silicon carbide MOSFET, the other end of the absorption capacitor is connected to the source of the silicon carbide MOSFET, and a group of absorption circuit modules are connected between the drain and source of the silicon carbide MOSFET.

7. The high-power inverter board based on silicon carbide MOSFET on a welding power supply according to claim 1 is characterized in that: The five parts of the full-bridge inverter main circuit module, the absorption circuit module, the drive circuit module, the drive-specific power supply circuit module, the drive power supply and the signal interface are located in one PCB.

8. The high-power inverter board based on silicon carbide MOSFET on a welding power supply according to claim 1, characterized in that: The full-bridge inverter main circuit module and the absorption circuit module are located in a PCB, and the drive circuit module, the drive-specific power supply circuit module, the drive power supply and the signal interface are located in a PCB board.

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