Converter valve based on light-controlled thyristors

Abstract

The invention discloses a converter valve based on light-controlled thyristors. The converter valve mainly comprises a rectifier bridge valve tower, valve base electronic equipment VBE and a valve control system TCamp. M, the rectifier bridge valve tower is mainly composed of a ground supporting structure, valve layers, a shielding cover and a valve lightning arrester, the converter valves are insulated from the ground supporting structure through rod-shaped post insulators, the valve layers are connected through the rod-shaped post insulators, a steel structure frame is installed on the valve layers, valve assemblies are fixedly installed on the steel structure frame, and the shielding cover is arranged on the shielding cover. The shielding cover is installed on the periphery of the valve assembly and fixed to the steel structure frame through screws, and the valve lightning arresters are connected with the converter valves in parallel and connected into the corresponding converter valves through buses; the valve assembly is connected with the valve base electronic equipment VBE and the valve control system TCamp through optical fibers. And M, communication connection. According to the converter valve provided by the invention, the light-controlled thyristors are adopted, the modular design is adopted for the valve assembly, the valve layers are vertically arranged up and down, the performance is reliable, the structure is compact, and maintenance and repair are convenient.

Description

Technical Field

[0001] The present invention belongs to the field of high-voltage direct current transmission, and in particular relates to a commutation valve based on a light-controlled thyristor. Background Art

[0002] The converter valve is one of the core devices in high-voltage direct current (HVDC) transmission projects. It is used to complete the conversion between alternating current (AC) and direct current (DC) during the DC transmission process. Its performance will directly affect the stability and reliability of the DC system operation.

[0003] Existing HVDC thyristor valves are categorized as electrically triggered and optically triggered, depending on their triggering method. Compared to electrically controlled thyristors, optically controlled thyristors can only be triggered by laser signals of a specific wavelength; other electrical signals or electric fields cannot cause them to conduct. Therefore, they exhibit superior anti-interference capabilities and increased reliability in high-voltage and strong magnetic field environments.

[0004] To make the converter valve compact, lightweight, and easy to install and maintain, the converter valve has evolved from a large frame-type converter valve assembly to a modular design with smaller components. This modular design consists of multiple valve assemblies, with the thyristor assembly being the smallest basic unit. The valve assemblies are mounted on a valve tower, the structure of which significantly impacts the performance, overall structure, and ease of maintenance of the converter valve. Summary of the Invention

[0005] The object of the present invention is to provide a commutation valve based on a light-controlled thyristor which has a compact structure, reliable functions and is easy to maintain and overhaul.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A converter valve based on a photo-controlled thyristor, the converter valve mainly comprising a rectifier bridge valve tower, a valve base electronic device (VBE), and a valve control system (TC&M); the rectifier bridge valve tower mainly comprises four parts: a ground support structure, a valve layer, a shielding cover, and a valve lightning arrester; the converter valve is insulated from the ground support structure by rod-shaped support insulators, the valve layers are connected by rod-shaped support insulators, a steel structure frame is mounted on the valve layer, and the valve assembly is fixedly mounted on the steel structure frame; the shielding cover is mounted around the valve assembly and fixed to the steel structure frame by screws; the valve lightning arrester is connected in parallel with the converter valve and connected to the corresponding converter valve via a busbar; the valve assembly is communicatively connected to the valve base electronic device (VBE) and the valve control system (TC&M) via optical fiber.

[0007] Furthermore, the valve assembly mainly includes a thyristor assembly and a reactor assembly. The thyristor assembly adopts a multi-stage series thyristor structure. The two thyristor assemblies are arranged in a rectangle, and two reactor assemblies are symmetrically placed at both ends. The two thyristor assemblies and four reactor assemblies are connected in series to form a valve layer.

[0008] Furthermore, the valve layers are arranged vertically up and down.

[0009] Furthermore, the valve control system TC&M includes two parts: control adjustment and optical fiber isolation trigger control. The control adjustment is completed by the TDC6 digital controller configured for each rectifier bridge, and the valve control system TC&M triggers the valve base electronic device VBE through optical fiber isolation.

[0010] The TDC6 digital controller is the core control unit of the rectifier control, realizing all the regulation triggering and control protection functions of the large-capacity thyristor rectifier current / voltage stabilization control system.

[0011] Furthermore, the thyristor assembly further includes a thyristor voltage detection unit TVM board, which is installed near each thyristor and connected in parallel with the thyristor.

[0012] The TVM board is equipped with positive voltage monitoring, negative voltage monitoring, and high voltage feedback modules. When the positive voltage across the thyristor exceeds 60V, the TVM generates a 2-3μs wide positive feedback signal. When the negative voltage across the thyristor exceeds -150V, the TVM generates a 6-8μs wide negative feedback signal. When the voltage across the thyristor exceeds 6500V, the TVM generates a 12-15μs wide high voltage feedback signal (BOD signal). All three feedback signals generated by the TVM board are transmitted to the valve base electronic device VBE via optical fiber through an optical transmission circuit.

[0013] Furthermore, the valve-based electronic device VBE includes an optical transmitting board, an optical receiving board, and a reverse recovery protection unit, namely an RPU control board; under the control of TC&M, the laser diode in the optical transmitting board is triggered, and the light pulse triggered by the laser diode is sent to the optically controlled thyristor in the thyristor assembly through the optical fiber, triggering the optically controlled thyristor to turn on; the optical receiving board receives three feedback signals from the TVM board, namely the positive voltage detection, negative voltage monitoring, and BOD signal; under the control of TC&M, the RPU control board starts the RPU protection circuit on the valve during the reverse recovery period of the thyristor, and the protection trigger light pulse emitted by the RPU protection circuit is transmitted to the optically controlled thyristor in the thyristor assembly through the optical fiber, thereby protecting the optically controlled thyristor in the thyristor assembly.

[0014] Furthermore, a hybrid optical coupler MSC is installed near each thyristor assembly. The MSC has two input ports and multiple output ports, and the output ports are connected to the photo-controlled gates of the photo-controlled thyristors through optical fibers. One input port of the MSC directly receives the trigger light pulses emitted by the laser diode in the VBE, mixes and evenly distributes them, and then sends them to the photo-controlled gates of each photo-controlled thyristor in the thyristor assembly through optical fibers, triggering the simultaneous opening of multiple stages of series-connected photo-controlled thyristors. During the reverse recovery period of the thyristor, the other input port of the MSC receives the protection trigger light pulses emitted by the RPU protection circuit. The protection trigger light pulses are mixed and evenly distributed to each photo-controlled thyristor in the thyristor assembly by the MSC, thereby protecting the photo-controlled thyristors in the thyristor assembly.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention adopts a light-controlled thyristor assembly as a basic unit, which has stable and reliable signals and strong resistance to high-voltage electromagnetic interference; The thyristor assembly and reactor assembly of the present invention adopt a standard modular design, with compact structure, reliable function and convenient installation and maintenance; The thyristor assembly and the reactor assembly of the present invention are placed in the shielding case, which further enhances the anti-interference capability and makes the performance more reliable; The valve layers of the present invention are arranged vertically up and down, which can make the valve tower structure more compact while meeting the requirements of electrical insulation, increase the space required for maintenance, and facilitate maintenance; The use of the hybrid optical coupler MSC in the present invention reduces the number of optical fibers used in the valve tower. At the same time, the MSC has a one-input port and multiple output ports, which can trigger the simultaneous opening of multiple-stage series-connected optical thyristors. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural diagram of the rectifier bridge valve tower of the present invention; Figure 2 This is a schematic diagram of a converter valve assembly according to the present invention; Figure 3 This is a block diagram of the converter valve triggering and detection system of the present invention; Explanation of the numbers in the figure: 1-insulator, 2-valve layer, 3-shielding cover, 4-reactor assembly, 5-steel structure frame, 6-thyristor assembly. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] The present invention provides a commutation valve based on a light-controlled thyristor, which mainly includes a rectifier bridge valve tower, a valve base electronic device VBE, and a valve control system TC&M; Figure 1As shown, the rectifier bridge valve tower is mainly composed of four parts: a ground support structure, a valve layer 2, a shielding cover 3 and a valve lightning arrester. The converter valve is insulated from the ground support structure by a rod-shaped support insulator 1. The valve layers 2 are connected by rod-shaped support insulators 1. A steel structure frame 5 is installed on the valve layer 2. The valve assembly is fixedly mounted on the steel structure frame 5. The shielding cover 3 is installed around the valve assembly and fixed to the steel structure frame 5 by screws. The valve lightning arrester is connected in parallel with the converter valve and connected to the corresponding converter valve through a busbar; the valve assembly is communicated with the valve base electronic equipment VBE and the valve control system TC&M through optical fiber.

[0019] like Figure 2 As shown, the valve assembly mainly includes a thyristor assembly 6 and a reactor assembly 4. The thyristor assembly 6 adopts a multi-stage series thyristor structure. Two thyristor assemblies 6 are arranged in a rectangle, and two reactor assemblies 4 are symmetrically placed at both ends. The two thyristor assemblies 6 and four reactor assemblies 4 are connected in series to form a valve layer.

[0020] The valve control system TC&M includes two parts: control adjustment and optical fiber isolation trigger control. The control adjustment is completed by the TDC6 digital controller configured for each rectifier bridge. The valve control system TC&M triggers the valve base electronic device VBE through optical fiber isolation.

[0021] The TDC6 digital controller is the core control unit of the rectifier control, realizing all the regulation triggering and control protection functions of the large-capacity thyristor rectifier current / voltage stabilization control system.

[0022] The thyristor assembly further includes a thyristor voltage detection unit TVM board, which is installed near each thyristor and connected in parallel with the thyristor.

[0023] The TVM board is equipped with positive voltage monitoring, negative voltage monitoring, and high voltage feedback modules. When the positive voltage across the thyristor exceeds 60V, the TVM generates a 2-3μs wide positive feedback signal. When the negative voltage across the thyristor exceeds -150V, the TVM generates a 6-8μs wide negative feedback signal. When the voltage across the thyristor exceeds 6500V, the TVM generates a 12-15μs wide high voltage feedback signal (BOD signal). Figure 3 As shown, the three return detection signals generated by the TVM board are transmitted to the valve base electronic equipment VBE via the optical fiber through the optical transmission circuit.

[0024] like Figure 3As shown, a hybrid optical coupler MSC is installed near each thyristor assembly. The MSC has two input ports and multiple output ports. One output port is connected to the optical gate of a light-controlled thyristor in the thyristor assembly through an optical fiber. The valve-based electronic device VBE includes an optical transmitter board, an optical receiver board, and a reverse recovery protection unit (RPU) control board. Under the control of the TC&M, the laser diode in the optical transmitter board is triggered. The light pulse triggered by the laser diode is sent to an input port of the MSC, mixed and evenly distributed by the MSC, and then sent to each thyristor assembly. The photo-controlled gate of a photo-controlled thyristor triggers the simultaneous opening of multiple series-connected thyristors. The light receiving board receives three return detection signals from the TVM board: positive voltage detection, negative voltage monitoring, and BOD signal. Under the control of the TC&M, the RPU control board activates the RPU protection circuit on the valve during the reverse recovery period of the thyristor. The protection trigger light pulse emitted by the RPU protection circuit is transmitted via optical fiber to another input port of the MSC. The MSC mixes and evenly distributes it to each photo-controlled thyristor in the thyristor assembly, thereby protecting the photo-controlled thyristors in the thyristor assembly.

[0025] Furthermore, the converter valve adopts a double valve structure, and three valve assemblies constitute a single valve, that is, three thyristor assemblies 6 and six reactor assemblies 4 are connected in series to form a single valve; two single valves are arranged up and down, that is, six valve assemblies form three valve layers, and the three valve layers are arranged vertically and assembled together to constitute two valves in one phase of the six-pulse converter.

[0026] The converter valve of the present invention adopts a light-controlled thyristor signal that is stable and reliable and has strong anti-interference ability, and its thyristor assembly and reactor assembly adopt a standard modular design, with a compact structure and easy installation and maintenance; the valve layers are arranged vertically up and down, which can make the valve tower structure more compact while meeting the requirements of electrical insulation, increase the space required for maintenance, and facilitate maintenance.

[0027] It should be understood that the above description is only for the purpose of explaining the invention in detail with reference to the accompanying drawings, rather than for the purpose of limiting the scope of the invention.

Claims

1. A commutation valve based on a light-controlled thyristor, characterized by: The converter valve mainly includes a rectifier bridge valve tower, valve base electronic equipment VBE, and a valve control system TC&M; the rectifier bridge valve tower mainly consists of four parts: a ground support structure, a valve layer, a shielding cover, and a valve lightning arrester. The converter valve is insulated from the ground support structure by rod-shaped support insulators, and the valve layers are connected by rod-shaped support insulators. A steel structure frame is installed on the valve layer, and the valve assembly is fixedly installed on the steel structure frame. The shielding cover is installed around the valve assembly and fixed to the steel structure frame by screws. The valve lightning arrester is connected in parallel with the converter valve and connected to the corresponding converter valve through a busbar; the valve assembly is connected to the valve base electronic equipment VBE and the valve control system TC&M for communication via optical fiber.

2. The commutation valve based on a light-controlled thyristor according to claim 1, characterized in that: The valve assembly mainly includes a thyristor assembly and a reactor assembly. The thyristor assembly adopts a multi-stage series thyristor structure. Two thyristor assemblies are arranged in a rectangle, and two reactor assemblies are symmetrically placed at both ends. The two thyristor assemblies and four reactor assemblies are connected in series to form a valve layer.

3. The commutation valve based on a light-controlled thyristor according to claim 2, characterized in that: The valve layers are arranged vertically up and down.

4. The commutation valve based on a light-controlled thyristor according to claim 3, characterized in that: The valve control system TC&M includes two parts: control and regulation and optical fiber isolation trigger control. The control and regulation are completed by the TDC6 digital controller configured for each rectifier bridge. The valve control system TC&M triggers the valve base electronic device VBE through optical fiber isolation.

5. The commutation valve based on a light-controlled thyristor according to claim 4, characterized in that: The thyristor assembly further includes a thyristor voltage monitoring unit TVM board, which is installed near each thyristor and connected in parallel with the thyristor.

6. The commutation valve based on a light-controlled thyristor according to claim 5, characterized in that: The TVM board is equipped with positive voltage monitoring, negative voltage monitoring, and high-voltage feedback modules. When the positive voltage across the thyristor exceeds 60V, the TVM generates a 2-3μs wide positive feedback signal. When the negative voltage across the thyristor falls below -150V, the TVM generates a 6-8μs wide negative feedback signal. When the voltage across the thyristor exceeds 6500V, the TVM generates a 12-15μs wide high-voltage feedback signal (BOD signal). All three feedback signals generated by the TVM board are transmitted to the valve base electronic device VBE via optical fiber through the optical transmission circuit.

7. The commutation valve based on a light-controlled thyristor according to claim 6, characterized in that: The valve-based electronic device VBE includes an optical transmitting board, an optical receiving board, and a reverse recovery protection unit, namely an RPU control board; under the control of TC&M, the laser diode in the optical transmitting board is triggered, and the light pulse triggered by the laser diode is sent to each optically controlled thyristor in the valve assembly through the optical fiber, triggering the optically controlled thyristor to turn on; the optical receiving board receives three feedback signals from the TVM board, namely the positive voltage detection, negative voltage monitoring, and BOD signal; under the control of TC&M, the RPU control board starts the RPU protection circuit on the valve during the reverse recovery period of the thyristor, and the protection trigger light pulse emitted by the RPU protection circuit is transmitted to each thyristor in the valve assembly through the optical fiber, thereby protecting the thyristor in the valve assembly.

8. The commutation valve based on a light-controlled thyristor according to claim 7, characterized in that: A hybrid optical coupler MSC is installed near each thyristor assembly. The MSC has two input ports and multiple output ports, and the output ports are connected to the photo-controlled gates of the photo-controlled thyristors through optical fibers. One input port of the MSC directly receives the trigger light pulses emitted by the laser diode in the VBE, mixes and evenly distributes them, and then sends them to the photo-controlled gates of each photo-controlled thyristor in the thyristor assembly through optical fibers, triggering the simultaneous opening of multiple stages of series-connected photo-controlled thyristors. During the reverse recovery period of the thyristor, the other input port of the MSC receives the protection trigger light pulses emitted by the RPU protection circuit. The protection trigger light pulses are mixed and evenly distributed to each photo-controlled thyristor in the thyristor assembly by the MSC, thereby protecting the photo-controlled thyristors in the thyristor assembly.

9. A commutation valve based on a light-controlled thyristor according to any one of claims 3 to 8, characterized in that: The converter valve adopts a double valve structure, with three valve assemblies constituting a single valve, that is, three thyristor assemblies and six reactor assemblies connected in series to form a single valve; the two single valves are arranged up and down, that is, the six valve assemblies form three valve layers arranged vertically and assembled together to form two valves in one phase of the six-pulse converter.

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