Power supply circuit for igct inverter valve

Abstract

The application relates to a power-taking power supply circuit of an IGCT converter valve, which comprises an input support capacitor, a switching resistance circuit, a high-voltage DC / DC converter, a current loop control circuit and an IGCT driving unit, the input support capacitor, the switching resistance circuit, the high-voltage DC / DC converter, the current loop control circuit and the IGCT driving unit are connected in series in sequence, one end of the input support capacitor is adapted to be electrically connected to the positive electrode of the power-taking power supply and the other end is grounded, the switching resistance circuit comprises an external switching resistance and a controllable circuit, one end of the external switching resistance is connected to the positive electrode of the input support capacitor and the other end is grounded, the drain of a field effect transistor is connected to the positive electrode of the input support capacitor through an adjusting resistance, the source of the field effect transistor is grounded, the gate of the field effect transistor is adapted to receive a control pulse signal, the anode of a reverse diode is connected to the source of the field effect transistor and the cathode is connected to the drain of the field effect transistor, the field effect transistor of the controllable circuit is turned on and off, and the input side equivalent resistance is adjusted in real time.

Description

Technical Field

[0001] This application relates to the field of IGCT converter valve technology, and in particular to a power supply circuit for IGCT converter valve. Background Technology

[0002] As a high-voltage, high-power power electronic device, the IGCT's drive unit requires a power supply to provide startup energy (such as charging the energy storage capacitor) and continuous drive power. Upon initial power-up, the IGCT drive unit needs its internal BUCK circuit to charge the capacitor to meet the drive energy requirements of the IGCT when the converter valve drive signal is given. This necessitates the IGCT drive unit's power supply providing a peak current of 10A. In some MMC applications, the DC support capacitor has a very small capacitance, only tens of µF, and its charging process is rapid and easily disturbed, leading to uneven DC voltage between submodules and affecting the system's stable startup. Utility Model Content

[0003] To address the problem of uneven DC voltage between traditional submodules, this invention provides a power supply circuit for an IGCT converter valve, comprising: an input support capacitor, a switching resistor circuit, a high-voltage DC / DC converter, a current loop control circuit, and an IGCT drive unit.

[0004] The input support capacitor, the switched resistor circuit, the high-voltage DC / DC converter, the current loop control circuit, and the IGCT drive unit are connected in series in sequence. One end of the input support capacitor is suitable for electrical connection to the positive terminal of the power supply, and the other end is grounded.

[0005] The switching resistor circuit includes an external switching resistor and a controllable circuit. One end of the external switching resistor is connected to the positive terminal of the input support capacitor, and the other end is grounded. The controllable circuit includes an adjustable resistor, a field-effect transistor (FET), and a reverse diode. The drain of the FET is connected to the positive terminal of the input support capacitor through the adjustable resistor. The source of the FET is grounded, and the gate of the FET is adapted to receive control pulse signals. The anode of the reverse diode is connected to the source of the FET, and the cathode is connected to the drain of the FET.

[0006] In one possible implementation, there are two controllable circuits, and the two or more controllable circuits are connected in parallel.

[0007] In one possible implementation, there are multiple regulating resistors connected in series.

[0008] In one possible implementation, the reverse diode is connected in parallel with the field-effect transistor.

[0009] One possible implementation also includes: a sampling resistor;

[0010] The external switching resistor is electrically connected to the input terminal of the high-voltage DC / DC converter.

[0011] One end of the sampling resistor is electrically connected to the output terminal of the high-voltage DC / DC converter, and the other end is electrically connected to the input terminal of the IGCT drive unit.

[0012] In one possible implementation, the input of the current loop control circuit is connected to the sampling resistor to acquire the voltage across the sampling resistor, and the output is connected to the high-voltage DC / DC converter.

[0013] In one possible implementation, the field-effect transistor is an N-channel enhancement-mode field-effect transistor.

[0014] In one possible implementation, the current loop control circuit incorporates a built-in PID adaptive control algorithm.

[0015] The beneficial effects of the power supply circuit for the IGCT converter valve in this application embodiment are as follows: By actively adjusting the DC voltage of the module through the switching resistor circuit, when the voltage of a certain module is too high, the resistor is connected to increase the loop loss and reduce its voltage. When the voltage of a certain module is too low, the resistor is disconnected to reduce the loss and increase its voltage. In this way, by controlling the on and off of the field-effect transistor of the controllable circuit, the equivalent resistance on the input side is adjusted in real time, thus solving the voltage balance problem of multi-module topologies such as MMC submodules.

[0016] Other features and aspects of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0017] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this application together with the specification and serve to explain the principles of this application.

[0018] Figure 1 This diagram shows the circuit connection of the power supply circuit for the IGCT converter valve according to an embodiment of this application. Detailed Implementation

[0019] Various exemplary embodiments, features, and aspects of this application will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0020] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model or simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0023] Furthermore, to better illustrate this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented without certain specific details. In some instances, methods, means, components, and circuits well-known to those skilled in the art have not been described in detail in order to highlight the main points of this application.

[0024] like Figure 1As shown, the power supply circuit for the IGCT converter valve in this embodiment includes: an input support capacitor 100, a switched resistor circuit 200, a high-voltage DC / DC converter 300, a current loop control circuit 400, and an IGCT drive unit 600. The input support capacitor 100, switched resistor circuit 200, high-voltage DC / DC converter 300, current loop control circuit 400, and IGCT drive unit 600 are connected in series. One end of the input support capacitor 100 is electrically connected to the positive terminal of the power supply, and the other end is grounded. The switched resistor circuit... Circuit 200 includes an external switching resistor 240 and a controllable circuit. One end of the external switching resistor 240 is connected to the positive terminal of the input support capacitor 100, and the other end is grounded. The controllable circuit includes an adjusting resistor 210, a field-effect transistor 230, and a reverse diode 220. The drain of the field-effect transistor 230 is connected to the positive terminal of the input support capacitor 100 through the adjusting resistor 210. The source of the field-effect transistor 230 is grounded, and the gate of the field-effect transistor 230 is suitable for receiving control pulse signals. The anode of the reverse diode 220 is connected to the source of the field-effect transistor 230, and the cathode is connected to the drain of the field-effect transistor 230.

[0025] In this specific embodiment, the DC voltage of the module is actively adjusted by the switching resistor circuit 200. When the voltage of a module is too high, the resistor is connected to increase the loop loss and reduce its voltage. When the voltage of a module is too low, the resistor is disconnected to reduce the loss and increase its voltage. In this way, the voltage balance problem of multiple module topologies such as MMC submodules is solved by adjusting the input equivalent resistance in real time through the switching of the field-effect transistor 230 of the controllable circuit.

[0026] In one specific embodiment, there are two controllable circuits, or more controllable circuits connected in parallel. Multiple branches share the current in parallel, adapting to application scenarios with larger currents and reducing the power loss of a single branch.

[0027] In one specific embodiment, there are multiple regulating resistors 210 connected in series. The branch resistance value is adjusted by the number of series resistors to adapt to different current limit requirements. In addition, the series resistors share the voltage stress, avoiding damage to a single resistor due to insufficient voltage withstand, and improving circuit reliability.

[0028] In one specific embodiment, the reverse diode 220 is connected in parallel with the field-effect transistor 230 to suppress the induced voltage spike at the drain of the field-effect transistor 230 when it is turned off, prevent device breakdown, and ensure stable circuit operation.

[0029] In one specific embodiment, the system further includes: a sampling resistor; an external switching resistor 240 is electrically connected to the input terminal of the high-voltage DC / DC converter 300, one end of the sampling resistor is electrically connected to the output terminal of the high-voltage DC / DC converter 300, and the other end is electrically connected to the input terminal of the IGCT drive unit 600. The newly added sampling resistor, with one end electrically connected to the output terminal of the high-voltage DC / DC converter 300 and the other end electrically connected to the input terminal of the IGCT drive unit 600, converts the output current of the high-voltage DC / DC converter 300 into a voltage signal, providing real-time feedback to the current loop control circuit 400, and enabling the monitoring and limiting of peak current.

[0030] In one specific embodiment, the input terminal of the current loop control circuit 400 is connected to the sampling resistor to collect the voltage across the sampling resistor, and the output terminal is connected to the high-voltage DC / DC converter 300. Through the PID closed-loop algorithm, in conjunction with the switching resistor circuit 200, the peak current surge during the power-on phase is suppressed in two ways, and the output of the high-voltage DC / DC converter is adjusted in real time to meet the instantaneous energy requirements of the IGCT drive unit 600.

[0031] In one specific embodiment, the field-effect transistor 230 is an N-channel enhancement-mode field-effect transistor 230.

[0032] In one specific embodiment, the current loop control circuit 400 incorporates a built-in PID adaptive control algorithm.

[0033] In one specific embodiment, the IGCT drive unit 600 includes: a switch CB, an anti-parallel diode, an energy storage capacitor, and a drive circuit. The positive terminal of the power supply of the IGCT drive unit 600 is connected to the output terminal Vo+ of the high-voltage DC / DC converter 300 and is connected in series with a sampling resistor. The negative terminal of the power supply is directly connected to the circuit ground, sharing a common ground with the negative terminal of the high-voltage DC / DC converter 300. The switch CB is connected in series between the output terminal of the sampling resistor and the internal circuitry of the drive unit, controlling the power supply switching of the drive unit. The anode of the anti-parallel diode is connected to the load side of the switch CB, and the cathode is connected to the power supply side of the switch CB, connected in anti-parallel to the switch CB. The energy storage capacitor is connected in parallel to the output terminals of the switch CB and the anti-parallel diode, converting the DC power supply into the drive signal required by the IGCT gate.

[0034] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A power supply circuit for harvesting energy from an IGCT converter valve, characterized in that, include: Input support capacitor, switched resistor circuit, high voltage DC / DC converter, current loop control circuit and IGCT drive unit; The input support capacitor, the switched resistor circuit, the high-voltage DC / DC converter, the current loop control circuit, and the IGCT drive unit are connected in series in sequence. One end of the input support capacitor is suitable for electrical connection to the positive terminal of the power supply, and the other end is grounded. The switching resistor circuit includes an external switching resistor and a controllable circuit. One end of the external switching resistor is connected to the positive terminal of the input support capacitor, and the other end is grounded. The controllable circuit includes an adjustable resistor, a field-effect transistor (FET), and a reverse diode. The drain of the FET is connected to the positive terminal of the input support capacitor through the adjustable resistor. The source of the FET is grounded, and the gate of the FET is adapted to receive control pulse signals. The anode of the reverse diode is connected to the source of the FET, and the cathode is connected to the drain of the FET.

2. The power supply circuit for the IGCT converter valve according to claim 1, characterized in that, There are two controllable circuits, and two or more controllable circuits are connected in parallel.

3. The power supply circuit for the IGCT converter valve according to claim 1, characterized in that, There are multiple regulating resistors, and the multiple regulating resistors are connected in series.

4. The power supply circuit for the IGCT converter valve according to claim 1, characterized in that, The reverse diode is connected in parallel with the field-effect transistor.

5. The power supply circuit for the IGCT converter valve according to claim 1, characterized in that, Also includes: Sampling resistor; The external switching resistor is electrically connected to the input terminal of the high-voltage DC / DC converter; One end of the sampling resistor is electrically connected to the output terminal of the high-voltage DC / DC converter, and the other end is electrically connected to the input terminal of the IGCT drive unit.

6. The power supply circuit for the IGCT converter valve according to claim 5, characterized in that, The input terminal of the current loop control circuit is connected to the sampling resistor to collect the voltage across the sampling resistor, and the output terminal is connected to the high-voltage DC / DC converter.

7. The power supply circuit for the IGCT converter valve according to claim 1, characterized in that, The field-effect transistor is an N-channel enhancement-mode field-effect transistor.

8. The power supply circuit for the IGCT converter valve according to claim 1, characterized in that, The current loop control circuit incorporates a built-in PID adaptive control algorithm.

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