High-power modular converter based on silicon carbide device

Abstract

The utility model relates to a high-power modular converter based on a silicon carbide device. The high-power modular converter comprises a power unit, a peripheral unit and a control unit, the power unit comprises a filter, a bridge rectifier, a transformer, a full-bridge inverter circuit and a full-wave rectifier circuit; the full-bridge inverter circuit adopts a silicon carbide MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor); the bridge rectifier and the full-wave rectification circuit adopt silicon carbide material diodes; the transformer adopts a ferrite high-frequency transformer; the full-bridge inverter circuit inverts a high direct current voltage into a high-frequency alternating current voltage, the high-frequency alternating current voltage is converted to a secondary side through the transformer, and then the voltage is output through the full-bridge inverter circuit. The high-power modular converter can switch a constant current / constant voltage mode, the working efficiency is greater than or equal to 94%, and both output voltage ripples and input voltage harmonics are lt; the antenna has the characteristics of high temperature, high voltage, high frequency, small size and the like, can normally work in environments with higher temperature, higher voltage and higher frequency, consumes less electric power, and is higher in durability and reliability.

Description

Technical Field

[0001] The utility model relates to the field of converters, and in particular to a high-power modular converter based on silicon carbide devices. Background Art

[0002] Although traditional Si power devices are widely used, they are not suitable for some high-voltage, high-temperature, high-efficiency and high-power density occasions due to the limitations of Si materials and structures.

[0003] In the existing modular converter, when the AC input voltage is filtered by the rectifier circuit, a higher DC voltage is obtained. The frequency conversion (IGBT) inverts the higher DC voltage into a high-frequency AC of about 15KHZ, which is converted to the secondary by the high-frequency transformer, and then rectified and filtered by the MOSFET to obtain the required output voltage. The control circuit samples the output voltage and output current, and generates a pulse width modulation (PWM) signal to control the power conversion circuit after closed-loop feedback to keep the output voltage and current stable. However, the existing modular converter has low output power (16kHz) and working efficiency (≤88%), high output voltage ripple (>20%) and input voltage harmonics (>15%), and large size. Summary of the invention

[0004] The utility model aims to solve the problems of large harmonics of power supply line voltage, low conversion efficiency, large output ripple, low power density, etc. in the current industry. A high-power modular converter based on silicon carbide devices is proposed, including a power unit, a peripheral unit and a control unit; the power unit includes a filter, a rectifier bridge stack, a transformer, a full-bridge inverter circuit, and a full-wave rectifier circuit.

[0005] The full-bridge inverter circuit adopts silicon carbide MOSFET;

[0006] The rectifier bridge stack and the full-wave rectifier circuit use silicon carbide diodes;

[0007] The transformer adopts a ferrite high-frequency transformer;

[0008] The full-bridge inverter circuit inverts the high DC voltage into a high-frequency AC voltage, transforms it to the secondary through the transformer, and then outputs a DC voltage through the full-wave rectifier circuit.

[0009] Furthermore, the target frequency value of the high-frequency AC voltage is 100KHZ.

[0010] Further, the peripheral unit includes a first sampling unit and a second sampling unit;

[0011] The first sampling unit is used to collect the input voltage and obtain the first sampling signal;

[0012] The second sampling unit is used to collect input voltage and current and obtain a second sampling signal.

[0013] Furthermore, the control unit processes the first sampling signal and the second sampling signal to generate a first control signal to control the full-bridge inverter circuit.

[0014] Furthermore, the first control signal is a pulse width modulation signal.

[0015] Furthermore, the peripheral unit also includes a PFC and harmonic compensation unit;

[0016] The PFC and harmonic compensation unit is connected to the power unit.

[0017] Furthermore, the control unit includes a DSP control panel, a human-computer interaction unit, and a remote control console;

[0018] Among them, the DSP control board and the human-computer interaction unit communicate via RS485;

[0019] The DSP control panel and the remote control console communicate via CAN.

[0020] Further, the peripheral unit also includes an auxiliary power supply circuit;

[0021] The auxiliary power supply circuit is used to supply power to the control unit; the input of the auxiliary power supply circuit comes from the input voltage of the converter.

[0022] Furthermore, the rated output current of the converter is 1000A; the rated output voltage is 60V; the rated output power is 60kW; and the output frequency is 100KHZ.

[0023] Furthermore, the output voltage ripple of the converter is less than 5%, and the input voltage harmonics is less than 5%.

[0024] The beneficial effects of the utility model are:

[0025] This high-power modular converter can switch between constant current and constant voltage modes, has working efficiency ≥94%, output voltage ripple and input voltage harmonics <5%, and is small in size. It can work normally in higher temperature, voltage and frequency environments, while consuming less power, and has stronger durability and reliability. This converter can be widely used in solar inverters, on-board power supplies, new energy vehicle motor controllers, UPS, charging piles, power supplies and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The utility model has the following drawings:

[0027] Figure 1This is a structural diagram of a high-power modular converter of the utility model;

[0028] Figure 2 This is a circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0029] The following is combined with Figure 1-2 The utility model is described in further detail.

[0030] like Figure 1 As shown, a high-power modular converter based on silicon carbide devices provided by the utility model includes a power unit, a peripheral unit and a control unit; the power unit includes a filter, a rectifier bridge stack, a transformer, a full-bridge inverter circuit, and a full-wave rectifier circuit, characterized in that the full-bridge inverter circuit adopts silicon carbide MOSFET; the rectifier bridge stack and the full-wave rectifier circuit adopt silicon carbide diodes; the transformer adopts a ferrite high-frequency transformer; the full-bridge inverter circuit inverts a high DC voltage into a high-frequency AC voltage, transforms it to the secondary through the transformer, and then outputs a DC voltage through the full-wave rectifier circuit.

[0031] The high-power modular converter described in the utility model converts the input voltage into a high-frequency current of about 100kHz after rectification and filtering by a three-phase rectifier module and a filter, and then converts the high DC voltage into a high-frequency current of about 100kHz through a full-bridge inverter unit composed of silicon carbide MOSFET, converts it to the secondary through a ferrite high-frequency transformer, and then obtains the required output voltage through rectification and filtering by a silicon carbide diode. The control unit samples the output voltage and output current, and generates a pulse width modulation (PWM) signal to control the power conversion circuit after closed-loop feedback, so that the output voltage and current remain stable.

[0032] like Figure 2As shown, the utility model adopts silicon carbide (SiC) MOSFET and diode components as core power devices, replacing the existing silicon (Si) IGBT and diode as core power devices to design a 60KW modular power supply. The third-generation wide bandgap semiconductor represented by silicon carbide (SiC) can work normally in higher temperature, voltage and frequency environments, while consuming less power, and having stronger durability and reliability. Silicon carbide semiconductor devices, with their high frequency, high efficiency and high temperature characteristics, are particularly suitable for applications with strict efficiency or temperature requirements. It can be widely used in solar inverters, on-board power supplies, new energy vehicle motor controllers, UPS, charging piles, power supplies and other fields. The energy loss of silicon carbide (SiC) power devices is only 50% of the power of silicon (Si) devices, and the heat generation is only 50% of that of silicon (Si) devices; and it has a higher current density. At the same power level, the volume of silicon carbide (SiC) power modules is significantly smaller than that of silicon (Si) power modules. Taking the intelligent power module (IPM) as an example, by using silicon carbide (SiC) power devices, the module volume can be reduced to 1 / 3 to 2 / 3 of the silicon (Si) power module.

[0033] It should be noted that the above is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A high-power modular converter based on silicon carbide devices, comprising a power unit, a peripheral unit and a control unit; the power unit comprises a filter, a rectifier bridge stack, a transformer, a full-bridge inverter circuit, and a full-wave rectifier circuit, characterized in that: The full-bridge inverter circuit adopts silicon carbide MOSFET; The rectifier bridge stack and the full-wave rectifier circuit use silicon carbide diodes; The transformer adopts a ferrite high-frequency transformer; The full-bridge inverter circuit inverts the high DC voltage into a high-frequency AC voltage, transforms it to the secondary through the transformer, and then outputs a DC voltage through the full-wave rectifier circuit.

2. The high-power modular converter based on silicon carbide devices according to claim 1, characterized in that: The target frequency value of the high-frequency AC voltage is 100KHZ.

3. The high-power modular converter based on silicon carbide devices according to claim 1, characterized in that: The peripheral unit includes a first sampling unit and a second sampling unit; The first sampling unit is used to collect the input voltage and obtain the first sampling signal; The second sampling unit is used to collect input voltage and current and obtain a second sampling signal.

4. The high-power modular converter based on silicon carbide devices according to claim 3, characterized in that: The control unit processes the first sampling signal and the second sampling signal to generate a first control signal to control the full-bridge inverter circuit.

5. The high-power modular converter based on silicon carbide devices according to claim 4, characterized in that: The first control signal is a pulse width modulation signal.

6. The high-power modular converter based on silicon carbide devices according to claim 1, characterized in that: The peripheral unit also includes a PFC and harmonic compensation unit; The PFC and harmonic compensation unit is connected to the power unit.

7. The high-power modular converter based on silicon carbide devices according to claim 1, characterized in that: The control unit includes a DSP control panel, a human-computer interaction unit, and a remote control console; Among them, the DSP control board and the human-computer interaction unit communicate via RS485; The DSP control panel and the remote control console communicate via CAN.

8. The high-power modular converter based on silicon carbide devices according to claim 1, characterized in that: The peripheral unit also includes an auxiliary power supply circuit; The auxiliary power supply circuit is used to supply power to the control unit; the input of the auxiliary power supply circuit comes from the input voltage of the converter.

9. The high-power modular converter based on silicon carbide devices according to claim 1, characterized in that: The rated output current of the converter is 1000A; the rated output voltage is 60V; the rated output power is 60kW; and the output frequency is 100KHZ.

10. The high-power modular converter based on silicon carbide devices according to claim 1, characterized in that: The output voltage ripple of the converter is less than 5%, and the input voltage harmonic is less than 5%.

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