An IGCT-MMC power module bypass device and method

Abstract

The present invention discloses an IGCT-MMC power module bypass device and method, which belongs to the field of power transmission IGCT converter valve bypass. The device includes: a bypass switch, a bypass drive board and a BOD board; the bypass switch includes a first coil and a second coil, the bypass drive board triggers the first coil to close the bypass switch, the BOD board triggers the second coil to close the bypass switch, the bypass switch is used to close or disconnect the bypass circuit, and the bypass circuit is used to bypass the IGCT-MMC power module. When the IGCT-MMC power module fails, the bypass switch is closed by the bypass drive or the BOD board. By setting two coils on the bypass switch, it is ensured that when one coil control fails, the bypass switch can continue to be controlled to close by the other coil, thereby ensuring reliable bypass of the IGCT-MMC power module and reliable power transmission of the converter valve based on the IGCT-MMC power module.

Description

Technical Field

[0001] The invention belongs to the field of IGCT converter valve power transmission bypass, and in particular relates to an IGCT-MMC power module bypass device and method. Background Art

[0002] Flexible high voltage direct current (MMC-HVDC) technology based on modular multilevel converter (MMC) has the advantages of independent regulation of active power and reactive power, low output voltage harmonic content, and can be connected to weak power grids and passive networks. In recent years, it has been widely used in the fields of asynchronous interconnection of AC power grids, distributed energy grid connection, and DC power grids. Compared with IGBT devices, IGCT devices have the advantages of high reliability, strong current carrying capacity, high blocking voltage, low conduction loss, and long-term current carrying after failure short circuit. Although the di / dt tolerance of some components is low, the di / dt tolerance problem can be solved by configuring buffer and absorption circuits, making it possible to use IGCT devices in the field of high-voltage and large-capacity flexible direct current transmission.

[0003] The existing bypass method is to bypass the IGCT-MMC power module when it fails to ensure the safety of the IGCT-MMC power module and the stable power transmission of the converter valve based on the IGCT-MMC power module. The existing bypass method is to first detect whether the power module has a fault, and drive the bypass circuit to close when a fault occurs to achieve bypass. However, the existing bypass is achieved by triggering the bypass switch of the bypass circuit to close through a driver. The existing triggering bypass switch generally triggers the corresponding coil to achieve the closure of the bypass switch. The existing method of triggering the coil is prone to trigger failure, resulting in bypass failure and unreliable bypass.

[0004] In summary, the existing method of closing the bypass switch by triggering the coil has the problem of unreliable bypass. Summary of the invention

[0005] The object of the present invention is to provide an IGCT-MMC power module bypass device and method to solve the problem of unreliable bypass in the existing method of closing the bypass switch by triggering a coil in the prior art.

[0006] To achieve the above object, the technical solution of an IGCT-MMC power module bypass device and method provided by the present invention is:

[0007] An IGCT-MMC power module bypass device comprises a bypass switch for bypassing an IGCT-MMC power module and a trigger coil for triggering the bypass switch. There are two trigger coils, namely a first coil and a second coil. The first coil is controlled and connected by a bypass drive board, and the second coil is controlled and connected by a BOD board. The bypass drive board triggers the first coil according to an IGCT-MMC power module fault signal sent by a central control board, and the active BOD circuit of the BOD board triggers the second coil according to the IGCT-MMC power module fault signal sent by the central control board or the voltage fault signal of an energy storage capacitor by the BOD board; the device also comprises an energy-taking power supply and a redundant power supply. The energy-taking power supply is used to supply power to the central control board and the bypass drive board; the redundant power supply is used to supply power to the central control board and the active BOD circuit, and is started when the energy-taking power supply fails.

[0008] The beneficial effect is that the central control board is used to detect the operating status of the IGCT-MMC power module. When a fault state is detected, the bypass switch is closed by controlling the bypass drive or the BOD board. By setting two coils on the bypass switch, it is ensured that when one coil fails to control, the bypass switch can continue to be controlled by the other coil to close, thereby ensuring reliable bypass of the IGCT-MMC power module and reliable power transmission of the converter valve based on the IGCT-MMC power module.

[0009] As a further improvement, the BOD board includes an active drive module, a passive drive module and an energy storage capacitor module. The active drive module is used to trigger the second coil according to the fault signal of the IGCT-MMC power module, and the passive drive module is used to trigger the second coil according to the voltage fault signal of the energy storage capacitor.

[0010] The beneficial effect is that in order to avoid the situation where the second coil is triggered to fail when the active BOD trigger circuit fails, a passive BOD trigger circuit is set to ensure the reliability of the bypass.

[0011] As a further improvement, the BOD board also includes a fiber optic communication module and an energy storage module; the active drive module is used to obtain the fault signal of the IGCT-MMC power module from the central control board through the fiber optic communication module, and the obtained fault signal triggers the second coil to form an active BOD circuit, and the energy storage module provides power for the active BOD circuit.

[0012] The beneficial effect is that the second coil is triggered in the active BOD circuit according to the fault signal of the IGCT-MMC power module obtained by the central control board, so that the bypass switch is closed and the IGCT-MMC power module is bypassed, thereby ensuring the safety of the IGCT-MMC power module.

[0013] As a further improvement, the BOD board also includes a capacitor voltage detection module; the capacitor voltage detection module is used to detect the voltage signal of the energy storage capacitor, and the active driving module triggers the second coil through the voltage fault signal obtained by the capacitor voltage detection module to form a passive BOD circuit; the energy storage capacitor is connected to the power supply circuit of the energy storage module for charging, and the energy storage capacitor discharges to provide electrical energy to the passive BOD circuit.

[0014] The beneficial effect is that a capacitor device is provided to avoid failure of the active BOD circuit, so that when the active BOD circuit fails, a closed circuit can be provided for the bypass switch, so that the BOD board can be bypassed stably. Because the passive BOD circuit is powered by an energy storage capacitor, and the energy storage capacitor is connected to the power supply circuit of the active BOD circuit for charging, when the power supply circuit of the active BOD circuit fails, the energy storage capacitor will discharge and the passive BOD circuit will be powered. When the active BOD circuit fails, the passive BOD circuit can be started according to the signal, so as to ensure the reliability of the bypass.

[0015] As a further improvement, the bypass drive board includes a fiber optic communication module, an energy storage module and a bypass drive; the fiber optic communication module is used to obtain the fault signal of the IGCT-MMC power module from the central control board, the bypass drive triggers the first coil according to the signal obtained by the fiber optic communication module, and the energy storage module provides power for the bypass drive board.

[0016] The beneficial effect is that the bypass drive board obtains the fault signal of the IGCT-MMC power module according to the central control board, so that the bypass drive triggers the first coil, so that the bypass switch is closed, and the bypass drive board is guaranteed to stably realize bypass.

[0017] As a further improvement, the energy-taking power supply supplies power to the energy storage module of the bypass driver board, and the redundant power supply supplies power to the energy storage module of the BOD board through the energy-taking voltage divider circuit.

[0018] The beneficial effects are: the energy-taking power supply supplies power to the energy storage module of the bypass drive board, and the redundant power supply supplies power to the energy storage module of the BOD board through the energy-taking voltage-dividing circuit, that is, the redundant power supply supplies power to the active BOD circuit. The redundant power supply is used to start when the energy-taking power supply fails; when there is a fault signal, the first coil is controlled to be triggered first, and then the second coil is controlled to be triggered.

[0019] The present invention also provides an IGCT-MMC power module bypass method, which is implemented by any one of the above-mentioned IGCT-MMC power module bypass devices, and the method comprises the following steps: according to a fault signal of the IGCT-MMC power module, controlling the bypass drive board to trigger the first coil to close the bypass switch; detecting whether the bypass switch is closed successfully, and if failed, controlling the BOD board to trigger the second coil to close the bypass switch.

[0020] The beneficial effect is that two circuits are designed to drive the bypass switch to close for the bypass IGCT-MMC power module, and the other circuit is started after one control fails. Specifically, one circuit is that the fault signal of the IGCT-MMC power module causes the bypass driver board to trigger the first coil to close the bypass switch; the other circuit is that the fault signal of the IGCT-MMC power module controls the BOD board to trigger the second coil to close the bypass switch. The two circuits ensure reliable bypass of the IGCT-MMC power module and reliable power transmission of the converter valve based on the IGCT-MMC power module.

[0021] As a further improvement, when controlling the BOD circuit to trigger the second coil, the active BOD circuit is first controlled to trigger the second coil. When the triggering fails, the passive BOD circuit is controlled to trigger the second coil according to the voltage fault signal of the energy storage capacitor.

[0022] The beneficial effect is that after the active BOD loop control fails, the passive BOD loop is controlled to trigger the second coil, thereby avoiding the failure of the bypass IGCT-MMC power module after the active BOD loop control fails, causing the converter valve power transmission failure, thereby ensuring the stable bypass process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the IGCT-MMC power module bypass device based on the turning IGCT device and the IGCT-MMC power module of the present invention;

[0024] Figure 2 It is a functional logic block diagram of the IGCT-MMC power module central control board of the IGCT-MMC power module bypass device of the present invention;

[0025] Figure 3 It is a functional logic block diagram of the IGCT-MMC power module bypass drive board of the IGCT-MMC power module bypass device of the present invention;

[0026] Figure 4 It is a functional block diagram of the IGCT-MMC power module BOD board of the IGCT-MMC power module bypass device of the present invention;

[0027] Figure 5 It is a schematic diagram of the flow of the IGCT-MMC power module bypass method of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0029] IGCT-MMC power module bypass device embodiment:

[0030] An IGCT-MMC power module bypass device is used to bypass the IGCT-MMC power module of a converter valve when the IGCT-MMC power module fails, so as to achieve the effect of protecting the IGCT-MMC power module.

[0031] like Figure 1-3 The device shown includes a bypass switch for bypassing the IGCT-MMC power module and a trigger coil for triggering the bypass switch; the bypass switch includes a first coil and a second coil, the bypass drive board is connected to the first coil for control, the BOD board is connected to the second coil for control, the bypass switch is used to close or disconnect the bypass circuit, and the bypass circuit is used to bypass the IGCT-MMC power module; the central control board is used to detect the operating state of the IGCT-MMC power module, and when a fault state is detected, the bypass switch is closed by controlling the corresponding first coil or second coil through the bypass drive or the BOD board. Among them, the two coils of the bypass switch are independent of each other and do not affect each other.

[0032] like Figure 4 As shown, the BOD board includes an active BOD loop and a passive BOD loop.

[0033] The BOD board includes a fiber optic communication module, an energy storage module, and a bypass drive; the fiber optic communication module is used to obtain the fault signal of the IGCT-MMC power module from the central control board, and the bypass drive triggers the second coil according to the signal obtained by the fiber optic communication module to form an active BOD circuit, and the energy storage module provides power for the active BOD circuit.

[0034] The BOD board also includes a capacitor voltage detection module; the energy storage capacitor is connected to the power supply circuit of the energy storage module for charging, the capacitor voltage detection module is used to detect the voltage of the energy storage capacitor, and the bypass drive is used to trigger the second coil when the detected voltage exceeds the first voltage threshold, forming a passive BOD circuit, and the energy storage capacitor discharges to provide electrical energy to the passive BOD circuit.

[0035] The central control board includes an energy-taking power supply and a redundant power supply. The energy-taking power supply is used to power the bypass drive, the redundant power supply is used to power the active BOD circuit, and the capacitor is used to power the passive BOD circuit; the redundant power supply is used to start after the energy-taking power supply fails, and the capacitor is used to discharge after the redundant power supply fails.

[0036] Specifically, the central control board includes an optical fiber communication module for realizing communication connection; and also includes a main control chip for realizing control of the bypass drive or BOD board. The optical fiber communication module of the central control board includes communication with the valve control device, bypass switch drive and BOD drive, the AD sampling module is responsible for capacitor voltage acquisition, the IGCT drive control module is responsible for communication with the drive, the bypass switch drive module is responsible for driving the bypass switch drive board to close the bypass switch, the energy supply voltage monitoring module is responsible for power supply voltage monitoring, and the redundant power supply module is responsible for powering the central control board. When the energy supply is normal, the redundant power supply module does not work. When the energy supply works abnormally, the redundant power supply module supplies power to the central control board; the bypass drive board energy storage capacitor is powered by the energy supply, and the bypass switch is closed by driving the first coil of the bypass switch by receiving the control signal of the central control board; the bypass drive module of the passive BOD loop does not rely on the central control board drive signal, and directly detects that the capacitor voltage reaches the action set value Uset2±ΔU2 and then drives the bypass switch to close. The bypass drive module of the passive BOD loop needs to receive the central control board drive signal before it can drive the bypass switch to close.

[0037] It also includes a transition IGCT device connected in parallel at both ends of the power module, and the transition IGCT device includes an overvoltage breakdown module and a voltage detection module; the voltage detection module is used to detect the voltage data of the IGCT-MMC power module. When the voltage data exceeds the second voltage threshold, the voltage breakdown module is controlled to break down the transition IGCT device, so that the transition IGCT short-circuits the power module to bypass the power module. Specifically, the voltage between the IGCT anode and cathode reaches U set1 After ±ΔU1 voltage, the IGCT device actively breaks down to bypass the IGCT-MMC power module.

[0038] like Figure 5 As shown, the steps of the method for implementing the IGCT-MMC power module bypass by the IGCT-MMC power module bypass device are as follows:

[0039] First, the central control unit obtains the voltage data of the IGCT-MMC power unit. When the voltage data exceeds the first voltage threshold, the power unit is determined to be faulty, and the bypass drive board is controlled to trigger the first coil to close the bypass switch; it detects whether the bypass switch is closed successfully. If it fails, the BOD board is controlled to trigger the second coil to close the bypass switch.

[0040] When controlling the BOD loop to trigger the second coil, the active BOD loop is first controlled to trigger the second coil, and when the triggering fails, the passive BOD loop is controlled to trigger the second coil.

[0041] When the above control circuits cannot close the bypass switch, the fault voltage will gradually increase. When the voltage that triggers the breakdown of the turning IGCT device is reached, the overvoltage breakdown module breaks down the turning IGCT device, so that the circuit where the turning IGCT device is located is short-circuited, that is, the circuit where the turning IGCT device is located is equivalent to the function of the bypass circuit to bypass the IGCT-MMC power module. That is, when the voltage data exceeds the second voltage threshold, the control voltage breakdown module breaks down the turning IGCT device, so that the turning IGCT short-circuits the power module and realizes the bypass of the power module; wherein the second voltage threshold is greater than the first voltage threshold. The current of the transmission circuit flows through the short-circuited IGCT device.

[0042] IGCT-MMC power module bypass method embodiment:

[0043] like Figure 5 As shown, the IGCT-MMC power module bypass method includes the following steps: the control unit obtains the voltage data of the IGCT-MMC power unit, and when the voltage data exceeds the first voltage threshold, the power unit is determined to be faulty, and the bypass drive board is controlled to trigger the first coil to close the bypass switch; whether the bypass switch is closed successfully, if it fails, the BOD board is controlled to trigger the second coil to close the bypass switch. The method is implemented by the above-mentioned embodiment of the IGCT-MMC power module bypass device, and the specific implementation method refers to the above-mentioned embodiment of the IGCT-MMC power module bypass device, which will not be repeated here.

[0044] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments without creative work, or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. An IGCT-MMC power module bypass device, comprising a bypass switch for bypassing the IGCT-MMC power module and a trigger coil for triggering the bypass switch, characterized in that: There are two trigger coils, namely the first coil and the second coil. The first coil is controlled and connected by the bypass drive board, and the second coil is controlled and connected by the BOD board. The bypass drive board triggers the first coil according to the IGCT-MMC power module fault signal sent by the central control board, and the active BOD circuit of the BOD board triggers the second coil according to the IGCT-MMC power module fault signal sent by the central control board or the BOD board triggers the second coil according to the voltage fault signal of the energy storage capacitor; it also includes an energy supply and a redundant power supply, the energy supply is used to power the central control board and the bypass drive board; the redundant power supply is used to power the central control board and the active BOD circuit, and is started when the energy supply fails.

2. The IGCT-MMC power module bypass device according to claim 1, characterized in that: The BOD board includes an active driving module, a passive driving module and an energy storage capacitor module. The active driving module is used to trigger the second coil according to a fault signal of the IGCT-MMC power module, and the passive driving module is used to trigger the second coil according to a voltage fault signal of the energy storage capacitor.

3. The IGCT-MMC power module bypass device according to claim 2, characterized in that: The BOD board also includes a fiber optic communication module and an energy storage module; the active drive module is used to obtain the fault signal of the IGCT-MMC power module from the central control board through the fiber optic communication module, and the obtained fault signal triggers the second coil to form an active BOD circuit, and the energy storage module provides power for the active BOD circuit.

4. The IGCT-MMC power module bypass device according to claim 3, characterized in that: The BOD board also includes a capacitor voltage detection module; the capacitor voltage detection module is used to detect the voltage signal of the energy storage capacitor, and the active drive module triggers the second coil through the voltage fault signal obtained by the capacitor voltage detection module to form a passive BOD circuit; the energy storage capacitor is connected to the power supply circuit of the energy storage module for charging, and the energy storage capacitor discharges to provide electrical energy to the passive BOD circuit.

5. The IGCT-MMC power module bypass device according to claim 3, characterized in that: The side-opening drive board includes an optical fiber communication module, an energy storage module and a side-opening drive; the optical fiber communication module is used to obtain a fault signal of the IGCT-MMC power module from the central control board, the side-opening drive triggers the first coil according to the signal obtained by the optical fiber communication module, and the energy storage module provides electrical energy for the side-opening drive board.

6. The IGCT-MMC power module bypass device according to claim 5, characterized in that: The energy-taking power supply supplies power to the energy storage module of the bypass drive board, and the redundant power supply supplies power to the energy storage module of the BOD board through the energy-taking voltage-dividing circuit.

7. An IGCT-MMC power module bypass method, characterized in that: The method is implemented by the IGCT-MMC power module bypass device according to any one of claims 1 to 6, and the method comprises the following steps: according to the fault signal of the IGCT-MMC power module, controlling the bypass drive board to trigger the first coil to close the bypass switch; Detect whether the bypass switch is closed successfully. If it fails, control the BOD board to trigger the second coil to close the bypass switch.

8. The IGCT-MMC power module bypass method according to claim 7, characterized in that: When the BOD circuit is controlled to trigger the second coil, the active BOD circuit is first controlled to trigger the second coil. When the trigger fails, the passive BOD circuit is controlled to trigger the second coil according to the voltage fault signal of the energy storage capacitor.

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