CN113271010B

CN113271010B - Power supply circuit applied to IGCT gate drive

Info

Publication number: CN113271010B
Application number: CN202010093401.1A
Authority: CN
Inventors: 曾宏; 李�灿; 曾理; 王三虎; 陈修林; 张顺彪; 龙海鸿; 罗慧; 唐清; 胡丹华
Original assignee: CRRC Zhuzhou Institute Co Ltd
Current assignee: CRRC Zhuzhou Institute Co Ltd
Priority date: 2020-02-14
Filing date: 2020-02-14
Publication date: 2022-08-05
Anticipated expiration: 2040-02-14
Also published as: CN113271010A

Abstract

The power supply circuit comprises a high-potential energy-taking unit, wherein a first input end of the high-potential energy-taking unit is connected with an anode of a GCT device, a second input end of the high-potential energy-taking unit is connected with a cathode of the GCT device, and the high-potential energy-taking unit is used for outputting a first voltage according to the voltage of the anode and the cathode of the GCT device; the input end of the DC/DC conversion unit is connected with the output end of the high-potential energy-taking unit, and the DC/DC conversion unit is used for converting the first voltage provided by the high-potential energy-taking unit into a second voltage and outputting the second voltage; and the input end of the gate driving unit is connected with the output end of the DC/DC conversion unit and is used for outputting the gate control current required by the GCT device according to the second voltage provided by the DC/DC conversion unit so as to realize self-power supply of the IGCT gate driving. The power supply circuit is simple in structure, does not need additional isolation measures, does not need ground power supply, does not need secondary voltage stabilization, and is higher in efficiency.

Description

Power supply circuit applied to IGCT gate drive

Technical Field

The disclosure relates to the field of electronic power control, in particular to a power supply circuit applied to IGCT gate drive.

Background

An Integrated Gate Commutated Thyristor (IGCT) is a novel power semiconductor switching device applied to a huge power electronic assembly developed by a medium voltage frequency converter. The IGCT includes a Gate Commutated Thyristor (GCT) and a Gate driving unit, and specifically, a Turn-off Thyristor (GTO), an anti-parallel diode, and a Gate driving circuit are integrated together and then connected to a Gate driver in a low inductance manner at the periphery. The IGCT has GTO high-blocking capability, low-pass voltage drop and the same switching performance as the IGBT, is an ideal megawatt-level and medium-voltage switching device and is widely applied to high-power medium-voltage converters.

The IGCT is used as a full-control type high-power semiconductor device, and can be applied to the field of power grids to replace thyristors like IGBT devices, a plurality of devices are required to be connected in series in the same bridge arm in a converter valve for high-voltage direct-current transmission, and static voltage equalizing and dynamic voltage equalizing are realized among different devices through voltage equalizing elements, so that power supply of a gate pole driving unit of the converter valve needs to be isolated at high voltage. When the existing IGCT device is applied in multi-stage series connection, a gate drive power supply mode mainly supplies power for ground transformer high-voltage isolation, the first implementation mode is that the power is supplied to each IGCT through AC/DC conversion after the transformer high-voltage isolation, the second implementation mode is that the power is supplied to each IGCT through AC/DC high-voltage isolation conversion, the second implementation mode is that a ground current source high-order CT induction coil and a conversion circuit supply power, and the three power supply modes need to supply power from the ground to an IGCT device end and are not suitable for the application of multi-series connection of a power grid.

Disclosure of Invention

In view of the above problems, the present disclosure provides a power supply circuit applied to an IGCT gate driver.

The present disclosure provides a power supply circuit applied to gate drive of an IGCT, including:

the high-potential energy-taking unit is connected with the anode of the GCT device at a first input end, connected with the cathode of the GCT device at a second input end and used for outputting a first voltage according to the voltage of the anode and the cathode of the GCT device;

the input end of the DC/DC conversion unit is connected with the output end of the high-potential energy-taking unit, and the DC/DC conversion unit is used for converting the first voltage provided by the high-potential energy-taking unit into a second voltage and outputting the second voltage;

and the input end of the gate driving unit is connected with the output end of the DC/DC conversion unit and is used for outputting the gate control current required by the GCT device according to the second voltage provided by the DC/DC conversion unit so as to realize self-power supply of the IGCT gate driving.

According to the embodiment of the present disclosure, preferably, the high potential energy-taking unit includes a resistor, a first capacitor, a first diode, a second capacitor, and a thyristor;

the first end of the resistor is a first input end of the high-potential energy-taking unit, the second end of the resistor is connected with the first end of the first capacitor, the second end of the first capacitor is connected with the cathode of the first diode, the anode of the first diode is the second input end of the high-potential energy-taking unit, the anode of the second diode is connected with the second end of the first capacitor, the cathode of the second diode is connected with the first end of the second capacitor, the second end of the second capacitor is connected with the anode of the first diode, the anode of the thyristor is connected with the anode of the second diode, the cathode of the thyristor is connected with the anode of the first diode, and the control electrode of the thyristor is connected with an external control circuit;

the first end of the second capacitor is a first output end of the high-potential energy-taking unit, and the second end of the second capacitor is a second output end of the high-potential energy-taking unit.

According to an embodiment of the present disclosure, preferably,

the cathode of the GCT device is grounded;

when the anode voltage of the GCT device is positive voltage, the first capacitor and the second capacitor are charged, when the voltage of the second capacitor reaches the first voltage, the thyristor is conducted through an external control circuit, the second capacitor stops charging, and the first capacitor continues charging;

when the anode voltage of the GCT device is negative voltage, the thyristor is automatically turned off, the second capacitor discharges, and the high-potential energy-taking unit outputs the first voltage.

According to the embodiment of the present disclosure, preferably, the DC/DC conversion unit includes a first transistor, a second transistor, a first inductor, and a third capacitor;

the drain of the first transistor is a first input end of the DC/DC conversion unit and is connected to a first output end of the high-potential energy-taking unit, the source of the first transistor is connected to the drain of the second transistor, the source of the second transistor is grounded, the gates of the first transistor and the second transistor are both connected to an external control circuit, the first end of the first inductor is connected to the source of the first transistor, the second end of the first inductor is a second input end of the DC/DC conversion unit and is connected to a second output end of the high-potential energy-taking unit, the first end of the third capacitor is connected to the source of the second transistor, and the second end of the third capacitor is connected to the second end of the first inductor;

the first end of the third capacitor is a first output end of the DC/DC conversion unit, and the second end of the third capacitor is a second output end of the DC/DC conversion unit.

According to the embodiment of the present disclosure, preferably, the high potential energy-taking unit includes a resistor, a first capacitor, a first diode, a second capacitor, a third capacitor, and a thyristor;

the first end of the resistor is a first input end of the high-potential energy-taking unit, the second end of the resistor is connected with the first end of the first capacitor, the second end of the first capacitor is connected with the cathode of the first diode, the anode of the first diode is the second input end of the high-potential energy-taking unit, the anode of the second diode is connected with the second end of the first capacitor, the cathode of the second diode is connected with the first end of the second capacitor, the second end of the second capacitor is connected with the first end of the third capacitor, the second end of the third capacitor is connected with the anode of the first diode, the anode of the thyristor is connected with the anode of the second diode, the cathode of the thyristor is connected with the anode of the first diode, and the control electrode of the thyristor is connected with an external control circuit;

the first end of the second capacitor is a first output end of the high-potential energy-taking unit, and the second end of the third capacitor is a second output end of the high-potential energy-taking unit.

According to an embodiment of the present disclosure, preferably,

the cathode of the GCT device is grounded;

when the anode voltage of the GCT device is a positive voltage, the first capacitor, the second capacitor and the third capacitor are charged, when the series voltage of the second capacitor and the third capacitor reaches the first voltage, the thyristor is conducted through an external control circuit, the second capacitor and the third capacitor stop charging, and the first capacitor continues to charge;

when the anode voltage of the GCT device is negative voltage, the thyristor is automatically turned off, the second capacitor and the third capacitor discharge, and the high-potential energy-taking unit outputs the first voltage.

According to the embodiment of the present disclosure, preferably, the DC/DC conversion unit includes a first transistor, a second transistor, a transformer, a third diode, a fourth diode, a first inductor, and a fourth capacitor;

wherein the drain of the first transistor is the first input end of the DC/DC conversion unit and is connected to the first output end of the high-potential energy-taking unit, the source of the first transistor is connected to the drain of the second transistor, the source of the second transistor is the second input end of the DC/DC conversion unit and is connected to the second output end of the high-potential energy-taking unit, the gates of the first transistor and the second transistor are both connected to an external control circuit, the first end of the primary winding of the transformer is connected to the second end of the second capacitor, the second end of the primary winding of the transformer is connected to the drain of the second transistor, the first end of the secondary winding of the transformer is connected to the anode of the third diode, the second end of the secondary winding of the transformer is grounded, the third end of the secondary winding of the transformer is connected to the anode of the fourth diode, the cathode of the third diode is connected with the first end of the first inductor, the cathode of the fourth diode is connected with the cathode of the third diode, the second end of the first inductor is connected with the first end of the fourth capacitor, and the second end of the fourth capacitor is connected with the second end of the secondary winding of the transformer;

a first end of the fourth capacitor is a first output end of the DC/DC conversion unit, and a second end of the fourth capacitor is a second output end of the DC/DC conversion unit.

According to the embodiment of the present disclosure, preferably, the first transistor and the second transistor are alternately turned on to convert the first voltage provided by the high-potential energy-taking unit into a second voltage and output the second voltage.

According to the embodiment of the present disclosure, preferably, the first transistor and the second transistor are both N-type MOSFETs.

According to the embodiment of the present disclosure, preferably, the gate driving unit includes a third transistor, a second inductor, a fourth transistor, a fifth transistor, a sixth transistor, and a control voltage converting unit, where the control voltage converting unit is configured to adjust a magnitude of the second voltage to regulate a magnitude of the gate control current required for turning on the GCT device;

wherein a source of the third transistor is a first input terminal of the gate driving unit and is connected to a first output terminal of the DC/DC converting unit, a drain of the third transistor is connected to a first terminal of the second inductor, a second terminal of the second inductor is connected to a source of the fourth transistor, a drain of the fourth transistor is a second input terminal of the gate driving unit and is connected to a second output terminal of the DC/DC converting unit, a source of the fifth transistor is connected to a drain of the third transistor, a drain of the fifth transistor is connected to a drain of the sixth transistor, a source of the sixth transistor is connected to a source of the third transistor, gates of the third transistor, the fourth transistor, the fifth transistor and the sixth transistor are all connected to an external control circuit, and a first terminal of the control voltage converting unit is connected to a source of the sixth transistor, the second end of the control voltage conversion unit is connected with the drain electrode of the fourth transistor;

and the drain electrode of the fifth transistor is the output end of the gate pole driving unit.

According to an embodiment of the present disclosure, preferably,

when the fourth transistor is conducted and the third transistor and the fifth transistor are conducted alternately, the gate driving unit outputs a gate control current required by the conduction of the GCT device so as to enable the GCT device to be in a conducting state;

when the sixth transistor is turned on, the gate of the GCT device is grounded, so that the GCT device is in an off state.

According to the embodiment of the present disclosure, preferably, the third transistor, the fourth transistor, the fifth transistor and the sixth transistor are all N-type MOSFETs.

By adopting the technical scheme, the following technical effects can be at least achieved:

the power supply circuit obtains voltage between an anode and a cathode of a GCT through the high-potential energy obtaining unit and outputs first voltage, and the first voltage is converted into second voltage and provided for the gate driving unit through the DC/DC conversion unit so as to output gate control current required by the GCT device and realize self-power supply of the IGCT gate driving. The power supply circuit has a simple structure, does not need additional isolation measures, does not need ground power supply, does not need secondary voltage stabilization, and has higher efficiency.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

FIG. 1 is a diagram of a connection framework for a power supply circuit for an IGCT gate drive according to an exemplary embodiment of the present disclosure;

FIG. 2 is a circuit diagram of a power supply circuit for an IGCT gate drive according to an exemplary embodiment of the present disclosure;

fig. 3 is a circuit diagram of another power supply circuit applied to an IGCT gate drive according to an exemplary embodiment of the present disclosure.

Detailed Description

Embodiments of the present disclosure will be described in detail with reference to the accompanying drawings and examples, so that how to apply technical means to solve technical problems and achieve the corresponding technical effects can be fully understood and implemented. The embodiments and the features of the embodiments of the present disclosure can be combined with each other without conflict, and the formed technical solutions are all within the protection scope of the present disclosure.

It will be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In order to provide a thorough understanding of the present disclosure, a detailed structure will be set forth in the following description in order to explain the technical solutions proposed by the present disclosure. The following detailed description of the preferred embodiments of the present disclosure, however, the present disclosure may have other embodiments in addition to these detailed descriptions.

Example one

Fig. 1 is a connection diagram of a power supply circuit 100 applied to an IGCT gate drive according to an exemplary embodiment of the present disclosure. As shown in fig. 1, the present disclosure provides a power supply circuit 100 for an IGCT gate driver, which includes a high-voltage power-taking unit 101, a DC/DC conversion unit 102, and a gate driver unit 103.

The high potential energy-taking unit 101 has a first input terminal connected to the anode of the GCT device and a second input terminal connected to the cathode of the GCT device, and is configured to output a first voltage U1 according to the voltages of the anode a and the cathode K of the GCT device.

And the input end of the DC/DC conversion unit 102 is connected to the output end of the high-potential energy-taking unit 101, and is configured to convert the first voltage U1 provided by the high-potential energy-taking unit 101 into a second voltage U2 and output a second voltage U2.

And the gate drive unit 103 is connected with the output end of the DC/DC conversion unit 102 at the input end thereof, and is used for outputting the gate control current required by the GCT device according to the second voltage U2 provided by the DC/DC conversion unit 102 so as to realize self-power supply of the IGCT gate drive.

It should be noted that the present disclosure mainly provides an IGCT self-powered manner for multi-stage series application of IGCT devices in a power grid, and solves the power supply problem of the IGCT gate driver unit.

Fig. 2 is a circuit diagram of a power supply circuit 100 applied to an IGCT gate drive according to an exemplary embodiment of the present disclosure.

Specifically, as shown in fig. 2, the high-potential energy-extracting unit 101 includes a resistor R1, a first capacitor C1, a first diode D1, a second diode D2, a second capacitor C2, and a thyristor SCR. The first end of the resistor R1 is the first input end of the high-potential energy-taking unit 101 and is connected to the anode a of the GCT device, the second end of the resistor R1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is connected to the cathode of the first diode D1, the anode of the first diode D1 is the second input end of the high-potential energy-taking unit 101 and is connected to the cathode K of the GCT device, the anode of the second diode D2 is connected to the second end of the first capacitor C1, the cathode of the second diode D2 is connected to the first end of the second capacitor C2, the second end of the second capacitor C2 is connected to the anode of the first diode D1, the anode of the thyristor SCR is connected to the anode of the second diode D2, the cathode of the thyristor SCR is connected to the anode of the first diode D1, and the control electrode of the SCR is connected to the external control circuit. The first terminal of the second capacitor C2 is the first output terminal of the high-voltage power-up unit 101, and the second terminal of the second capacitor C2 is the second output terminal of the high-voltage power-up unit 101.

In this embodiment, the working principle of the high-potential energy-taking unit 101 is as follows: an alternating current voltage signal is arranged between an anode A and a cathode K of the GCT device, and the cathode K is grounded. When positive voltage is input to the anode a, the first capacitor C1 and the second capacitor C2 are charged through the resistor R1 (the voltage direction of the second capacitor C2 is positive at the first end, and the second end is grounded), when the voltage of the second capacitor C2 reaches the first voltage U1, the thyristor SCR is turned on through the external control circuit, the second capacitor C2 stops charging, and the first capacitor C1 continues charging;

when a negative voltage is input to the anode a, the thyristor SCR is automatically turned off, a structure in which the resistor R1 and the first capacitor C1 are connected in parallel with the anode a and the cathode K of the GCT device is formed, the second capacitor C2 discharges to the DC/DC conversion unit 102, and the high-potential energy-taking unit 101 outputs the first voltage U1. The first voltage U1 is a preset value, and can be set as required.

The DC/DC conversion unit 102 includes a first transistor V1, a second transistor V2, a first inductor L1, and a third capacitor C3. The drain of the first transistor V1 is the first input terminal of the DC/DC conversion unit 102 and is connected to the first output terminal of the high-voltage energy-extracting unit 101 (i.e., connected to the first terminal of the second capacitor C2), the source of the first transistor V1 is connected to the drain of the second transistor V2, the source of the second transistor V2 is grounded GND, the gates of the first transistor V1 and the second transistor V2 are both connected to the external control circuit, the first terminal of the first inductor L1 is connected to the source of the first transistor V1, the second terminal of the first inductor L1 is the second input terminal of the DC/DC conversion unit 102 and is connected to the second output terminal of the high-voltage energy-extracting unit 101 (i.e., connected to the second terminal of the second capacitor C2), the first terminal of the third capacitor C3 is connected to the source of the second transistor V2, i.e., grounded GND, and the second terminal of the third capacitor C3 is connected to the second terminal of the first inductor L1. A first terminal of the third capacitor C3 is a first output terminal of the DC/DC converting unit 102, and a second terminal of the third capacitor C3 is a second output terminal of the DC/DC converting unit 102.

In this embodiment, the first transistor V1 and the second transistor V2 are both N-type MOSFETs. The DC/DC conversion unit 102 is a high-frequency non-isolated DC/DC conversion unit, and also functions as an electrical isolation.

In this embodiment, the operating principle of the DC/DC conversion unit 102 is as follows: the first transistor V1 and the second transistor V2 are alternately turned on. The first stage is as follows: the first transistor V1 is turned on, the second transistor V2 is turned off, and the first voltage U1 charges the first inductor L1; and a second stage: the first transistor V1 is turned off, the second transistor V2 is turned on, the first inductor L1 freewheels, the generated current flows from the first end of the first inductor L1 to the second end, the current charges the third capacitor C3, the voltage direction of the third capacitor C3 is the first end grounded GND, and the second end is positive. And a third stage: when the second transistor V2 is turned off again, the third capacitor C3 discharges, and the DC/DC conversion unit 102 outputs the second voltage U2.

The gate driving unit 103 includes a third transistor V3, a second inductor L2, a fourth transistor V4, a fifth transistor V5, a sixth transistor Voff, and a control voltage converting unit, where the control voltage converting unit is configured to adjust the second voltage U2 to regulate the gate control current required for turning on the GCT device. Wherein the source of the third transistor V3 is the first input terminal of the gate driving unit 103 and is connected to the first output terminal of the DC/DC converting unit 102 (i.e. connected to the first terminal of the third capacitor C3, i.e. grounded GND), the drain of the third transistor V3 is connected to the first terminal of the second inductor L2, the second terminal of the second inductor L2 is connected to the source of the fourth transistor V4, the drain of the fourth transistor V4 is the second input terminal of the gate driving unit 103 and is connected to the second output terminal of the DC/DC converting unit 102 (i.e. connected to the second terminal of the third capacitor C3), the source of the fifth transistor V5 is connected to the drain of the third transistor V3, the drain of the fifth transistor V5 is connected to the drain of the sixth transistor Voff, the source of the sixth transistor Voff is connected to the source of the third transistor V3, i.e. grounded GND, the third transistor V3, the fourth transistor V4, the gate of the fifth transistor V5 and the sixth Voff are all connected to the external control circuit, a first terminal of the control voltage converting unit is connected to the source of the sixth transistor Voff, and a second terminal of the control voltage converting unit is connected to the drain of the fourth transistor V4. The drain of the fifth transistor V5 is the output terminal of the gate driving unit 103 for outputting the gate control current.

In this embodiment, the third transistor V3, the fourth transistor V4, the fifth transistor V5, and the sixth transistor Voff are all N-type MOSFETs.

The working principle of the gate drive unit 103 is as follows: when the fourth transistor V4 is turned on and cooperates with the alternate turning on of the third transistor V3 and the fifth transistor V5, the gate driving unit 103 outputs a gate control current (the GCT device is a current control device) required for turning on the GCT device, so that the GCT device is in a turned-on state. Specifically, the first stage: the third transistor V3 and the fourth transistor V4 are turned on, the fifth transistor V5 is turned off, and the second voltage U2 charges the second inductor L2; and a second stage: the fourth transistor V4 and the fifth transistor V5 are turned on, the third transistor V3 is turned off, the second inductor L2 freewheels, and the generated current flows from the second end to the first end of the second inductor L2, and the current flows to the gate G of the GCT device through the fifth transistor V5, that is, the gate driving current is output from the drain of the fifth transistor V5. The control voltage conversion unit can regulate and control the magnitude of the gate driving current so as to conduct the GCT device. When the sixth transistor Voff is turned on, the gate of the GCT device is grounded to GND, and the GCT device is in an off state.

The embodiment of the present disclosure provides a power supply circuit 100 applied to an IGCT gate driver, including a high-voltage energy obtaining unit 101, a DC/DC conversion unit 102 and a gate driver unit 103, where the power supply circuit 100 obtains a voltage between an anode a and a cathode K of a GCT device through the high-voltage energy obtaining unit 101 and outputs a first voltage U1, and then converts the first voltage U1 into a second voltage U2 through the DC/DC conversion unit 102 and provides the second voltage U2 to the gate driver unit 103, so as to output a gate control current required by the GCT device, thereby realizing self-powering of the IGCT gate driver. The power supply circuit is simple in structure, does not need additional isolation measures, does not need ground power supply, does not need secondary voltage stabilization, and is higher in efficiency.

Example two

The embodiment of the present disclosure provides another power supply circuit 200 applied to an IGCT gate driver, which includes a high-voltage power-taking unit 201, a DC/DC conversion unit 202, and a gate driver unit 203. The connection frame diagram is the same as the first embodiment, and is not described again here.

The high potential energy-taking unit 201 is connected with the anode of the GCT device at a first input end, connected with the cathode of the GCT device at a second input end, and used for outputting a first voltage U1 according to the voltage of the anode A and the cathode K of the GCT device.

And a DC/DC conversion unit 202, an input terminal of which is connected to the output terminal of the high-potential energy-taking unit 201, for converting the first voltage U1 provided by the high-potential energy-taking unit 201 into a second voltage U2 and outputting the second voltage U2.

And the gate drive unit 203, the input end of which is connected to the output end of the DC/DC conversion unit 202, is used for outputting the gate control current required by the GCT device according to the second voltage U2 provided by the DC/DC conversion unit 202, so as to realize self-power supply of the IGCT gate drive.

Fig. 3 is a circuit diagram of another power supply circuit 200 applied to an IGCT gate drive according to an exemplary embodiment of the present disclosure.

Specifically, as shown in fig. 3, the high-potential energy-extracting unit 201 includes a resistor R1, a first capacitor C1, a first diode D1, a second diode D2, a second capacitor C2, a third capacitor C3, and a thyristor SCR. The first end of the resistor R1 is the first input end of the high-voltage energy-taking unit 201 and is connected to the anode a of the GCT device, the second end of the resistor R1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is connected to the cathode of the first diode D1, the anode of the first diode D1 is the second input end of the high-voltage energy-taking unit 201 and is connected to the cathode K of the GCT device, the anode of the second diode D2 is connected to the second end of the first capacitor C1, the cathode of the second diode D2 is connected to the first end of the second capacitor C2, the second end of the second capacitor C2 is connected to the first end of the third capacitor C3, the second end of the third capacitor C3 is connected to the anode of the first diode D1, the anode of the thyristor SCR is connected to the anode of the second diode D2, the cathode of the SCR is connected to the anode of the first diode D1, and the control electrode of the SCR is connected to the external control circuit. The first terminal of the second capacitor C2 is the first output terminal of the high-voltage power-up unit 201, and the second terminal of the third capacitor C3 is the second output terminal of the high-voltage power-up unit 201.

In this embodiment, the working principle of the high-potential energy-taking unit 201 is as follows: an alternating current voltage signal is arranged between an anode A and a cathode K of the GCT device, and the cathode K is grounded. When positive voltage is input to the anode a, the first capacitor C1, the second capacitor C2 and the third capacitor C3 are charged through the resistor R1 (the direction of the series voltage of the second capacitor C2 and the third capacitor C3 is that the first end of the second capacitor C2 is positive, the second end of the third capacitor C3 is grounded), when the series voltage of the second capacitor C2 and the third capacitor C3 reaches the first voltage U1, the thyristor SCR is turned on through the external control circuit, the second capacitor C2 and the third capacitor C3 stop charging, and the first capacitor C1 continues to charge; when a negative voltage is input to the anode a, the thyristor SCR is automatically turned off, a structure in which the resistor R1 and the first capacitor C1 are connected in parallel with the anode a and the cathode K of the GCT device is formed, the second capacitor C2 and the third capacitor C3 discharge to the DC/DC conversion unit 202, and the high-potential energy-taking unit 201 outputs the first voltage U1. The first voltage U1 is a preset value, and can be set as required.

The DC/DC conversion unit 202 includes a first transistor V1, a second transistor V2, a transformer T1, a third diode D3, a fourth diode D4, a first inductor L1, and a fourth capacitor C4. Wherein, the drain of the first transistor V1 is the first input terminal of the DC/DC converting unit and is connected to the first output terminal of the high-potential energy-taking unit 201, i.e. is connected to the first terminal of the second capacitor C2, the source of the first transistor V1 is connected to the drain of the second transistor V2, the source of the second transistor V2 is the second input terminal of the DC/DC converting unit and is connected to the second output terminal of the high-potential energy-taking unit 201, i.e. is connected to the second terminal of the third capacitor C3, the gates of the first transistor V1 and the second transistor V2 are both connected to the external control circuit, the first terminal of the primary winding of the transformer T1 is connected to the second terminal of the second capacitor C2, the second terminal of the primary winding of the transformer T1 is connected to the drain of the second transistor V2, the first terminal of the secondary winding of the transformer T1 is connected to the anode of the third diode D3, the second terminal of the secondary winding of the transformer T1 is grounded, the third terminal of the secondary winding of the transformer T1 is connected to the anode of the fourth diode D4, the cathode of the third diode D3 is connected to the first terminal of the first inductor L1, the cathode of the fourth diode D4 is connected to the cathode of the third diode D3, the second terminal of the first inductor L1 is connected to the first terminal of the fourth capacitor C4, and the second terminal of the fourth capacitor C4 is connected to the second terminal of the secondary winding of the transformer T1. A first terminal of the fourth capacitor C4 is a first output terminal of the DC/DC converting unit 202, and a second terminal of the fourth capacitor C4 is a second output terminal of the DC/DC converting unit 202.

In this embodiment, the first transistor V1 and the second transistor V2 are both N-type MOSFETs. The DC/DC conversion unit 202 is a half-bridge type isolated DC/DC conversion unit.

In this embodiment, the operating principle of the DC/DC conversion unit 202 is as follows: the first transistor V1 and the second transistor V2 are alternately turned on. The conduction time is the same, but not at the same time. The voltage across the fourth capacitor C4, i.e., the second voltage U2, is related to the first voltage U1, the number of turns in the primary and secondary windings of the transformer.

In this embodiment, the first terminal of the fourth capacitor C4 is positive, and the second terminal is grounded, so that the DC/DC converting unit 202 is further connected to the gate driving unit 203 via a potential converting unit (not shown) for converting the second voltage U2 to drive the gate driving unit 203.

In this embodiment, the specific circuit (not shown) of the gate driving unit 203 is the same as the circuit of the gate driving unit 103 in the first embodiment. Similarly, the gate driving unit 203 includes a third transistor V3, a second inductor L2, a fourth transistor V4, a fifth transistor V5, a sixth transistor Voff, and a control voltage converting unit, where the control voltage converting unit is configured to adjust the magnitude of the second voltage U2 to regulate the magnitude of the gate control current required for turning on the GCT device. Wherein the source of the third transistor V3 is the first input terminal of the gate driving unit 203 and is connected to the first output terminal of the DC/DC converting unit 202, the drain of the third transistor V3 is connected to the first terminal of the second inductor L2, the second terminal of the second inductor L2 is connected to the source of the fourth transistor V4, the drain of the fourth transistor V4 is the second input terminal of the gate driving unit 203 and is connected to the second output terminal of the DC/DC converting unit 202, the source of the fifth transistor V5 is connected to the drain of the third transistor V3, the drain of the fifth transistor V5 is connected to the drain of the sixth transistor Voff, the source of the sixth transistor Voff is connected to the source of the third transistor V3, the gates of the third transistor V3, the fourth transistor V4, the fifth transistor V5 and the sixth transistor Voff are all connected to the external control circuit, the first terminal of the control voltage converting unit is connected to the source of the sixth transistor Voff, the second terminal of the control voltage converting unit is connected to the drain of the fourth transistor V4. The drain of the fifth transistor V5 is the output terminal of the gate drive unit 203.

In this embodiment, the working principle of the gate driving unit 203 is the same as that of the gate driving unit 103 in the first embodiment, and is not described herein again.

The embodiment of the present disclosure provides a power supply circuit 200 applied to an IGCT gate driver, including a high-voltage energy obtaining unit 201, a DC/DC conversion unit 202 and a gate driver unit 203, where the power supply circuit 200 obtains a voltage between an anode a and a cathode K of a GCT device through the high-voltage energy obtaining unit 201 and outputs a first voltage U1, and then converts the first voltage U1 into a second voltage U2 through the DC/DC conversion unit 202 and supplies the second voltage U2 to the gate driver unit 203, so as to output a gate control current required by the GCT device, thereby realizing self-powering of the IGCT gate driver. The power supply circuit is simple in structure, does not need additional isolation measures, does not need ground power supply, does not need secondary voltage stabilization, and is higher in efficiency.

The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure, and various modifications and changes may be made to the present disclosure by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure. Although the embodiments disclosed in the present disclosure are described above, the embodiments are merely used for understanding the present disclosure, and are not intended to limit the present disclosure. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure, and that the scope of the disclosure is to be limited only by the appended claims.

Claims

1. A power supply circuit for an IGCT gate drive, comprising:

the input end of the gate driving unit is connected with the output end of the DC/DC conversion unit and is used for outputting the gate control current required by the GCT device according to the second voltage provided by the DC/DC conversion unit so as to realize self-power supply of the IGCT gate driving;

the gate driving unit comprises a third transistor, a second inductor, a fourth transistor, a fifth transistor, a sixth transistor and a control voltage conversion unit, wherein the control voltage conversion unit is used for adjusting the second voltage so as to regulate and control the gate control current required by the conduction of the GCT device;

2. The power supply circuit applied to the IGCT gate drive of claim 1, wherein the high-potential energy-taking unit comprises a resistor, a first capacitor, a first diode, a second capacitor and a thyristor;

3. The power supply circuit for IGCT gate drive of claim 2, wherein:

the cathode of the GCT device is grounded;

4. The power supply circuit applied to the IGCT gate drive of claim 2, wherein the DC/DC conversion unit comprises a first transistor, a second transistor, a first inductor and a third capacitor;

5. The power supply circuit applied to the IGCT gate drive of claim 1, wherein the high-potential energy-taking unit comprises a resistor, a first capacitor, a first diode, a second capacitor, a third capacitor and a thyristor;

6. The power supply circuit for IGCT gate drive of claim 5, wherein:

the cathode of the GCT device is grounded;

7. The power supply circuit applied to the IGCT gate drive of claim 5, wherein the DC/DC conversion unit comprises a first transistor, a second transistor, a transformer, a third diode, a fourth diode, a first inductor and a fourth capacitor;

8. The power supply circuit as claimed in claim 4 or 7, wherein the first transistor and the second transistor are turned on alternately to convert the first voltage provided by the high-potential energy-taking unit into a second voltage and output the second voltage.

9. The power supply circuit for IGCT gate drive of claim 4 or claim 7, wherein the first transistor and the second transistor are both N-type MOSFETs.

10. The power supply circuit for IGCT gate drive of claim 1, wherein:

11. The power supply circuit applied to the IGCT gate drive of claim 1, wherein the third transistor, the fourth transistor, the fifth transistor and the sixth transistor are all N-type MOSFETs.