Converter valve assembly based on light-controlled thyristors

Abstract

The invention discloses a converter valve assembly based on light-controlled thyristors. The assembly mainly comprises an assembly frame with a shielding cover, a light-controlled thyristor assembly, a damping resistor-capacitor unit, a reactor assembly and a water pipe. The assembly frame is a steel structure frame, the shielding cover is fixed on the steel structure frame through screws, the assembly frame is a mechanical supporting structure frame of the whole assembly, and the light-controlled thyristor assembly and the reactor assembly are both assembled on the assembly frame and arranged in the shielding cover; the light-controlled thyristor assemblies and the reactor assemblies adopt modular design, the reactor assemblies are symmetrically placed on two sides of the thyristor assemblies, and each thyristor assembly is connected in series with the two reactor assemblies. The light-controlled thyristor assembly and the reactor assembly serve as basic units of the converter valve assembly, modular design is adopted, meanwhile, the shielding cover is installed outside the assemblies, the high-voltage electromagnetic interference resistance is high, signals are stable and reliable, the structure is compact, and installation and maintenance 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 assembly 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] Existing HVDC converter valves are divided into shielded large-frame converter valve assemblies and unshielded modular converter valve assemblies based on their structure. Modular converter valve assemblies offer compact structure, reliable function, and ease of installation and maintenance. CN108011530A discloses a converter valve assembly based on light-controlled thyristors. This converter valve assembly adopts a modular design, but does not disclose its shielding function. Summary of the Invention

[0005] The object of the present invention is to provide a commutation valve assembly based on a light-controlled thyristor with a compact structure, reliable functions, convenient installation and maintenance, and a shielding function.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A commutation valve assembly based on a light-controlled thyristor comprises an assembly frame with a shielding cover, a light-controlled thyristor assembly, a damping resistor and capacitor unit, a reactor assembly, and a water pipe; The assembly frame is a steel structure frame, and the shielding cover is fixed to the steel structure frame by screws. The assembly frame is the mechanical support structure frame of the entire assembly. The light-controlled thyristor assembly and the reactor assembly are both assembled on the assembly frame and placed in the shielding cover; The light-controlled thyristor assembly is arranged in a rectangular shape and mainly consists of an end plate, a clamping plate, a multi-stage series-connected light-controlled thyristor, a heat sink, and a disk-spring unit. The two end plates and the two clamping plates support and fix the light-controlled thyristor, the heat sink, and the disk-spring unit. The light-controlled thyristor and the heat sink are stacked and connected in series in sequence. The damping resistor and capacitor unit is composed of a capacitor and a direct water-cooled resistor connected in series, and is connected in parallel with each light-controlled thyristor to make the voltage distribution between the thyristors uniform; The reactor components are symmetrically placed on both sides of the thyristor components, each thyristor component is connected in series with two reactor components, the iron core and coil of the reactor are cast in an insulating shell, and the heat generated by the reactor is directly cooled by cooling water flowing through the coil guide tube; The water pipes mainly include a main water pipe, a branch water pipe in the valve assembly, and a branch water pipe in the radiator in the thyristor assembly connected to the branch water pipe.

[0007] The above-mentioned reactor assembly is connected in series with the photo-controlled thyristor assembly, which can effectively limit the rising speed of the current in the initial stage of conduction of the photo-controlled thyristor, and avoid local overheating and damage of the photo-controlled thyristor; at the same time, the reactor assembly cooperates with the above-mentioned damping capacitor and resistor to further improve the uneven voltage distribution between the photo-controlled thyristors connected in series.

[0008] Furthermore, the disc spring unit in the light-controlled thyristor assembly is a disc spring.

[0009] Furthermore, the light-controlled thyristor assembly further includes a thyristor voltage detection unit, namely a TVM circuit board. Each light-controlled thyristor is equipped with one of the thyristor voltage detection units (TVM circuit board), which are connected in parallel.

[0010] Furthermore, the water channels of the branch water pipes in the radiator are connected in parallel.

[0011] Furthermore, in order to ensure that no voltage difference is generated at both ends of the branch water pipe connecting the thyristor radiator and the branch water pipe, and to avoid electrical corrosion of the radiator due to electrolytic current, platinum electrodes are installed at the branch water pipe positions at both ends of the thyristor assembly.

[0012] 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 both placed in the shielding cover, which further reduces high-voltage electromagnetic interference and enhances the stability and reliability of the converter valve performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of the structure of the converter valve assembly of the present invention; Figure 2 Schematic diagram of the shielding cover of the converter valve assembly of the present invention; Figure 3 Schematic diagram of the structure of the light-controlled thyristor assembly of the present invention; Explanation of the numbers in the figure: 1: component frame, 2: photo-controlled thyristor component, 3: reactor component, 4: shielding cover, 2-1: end plate, 2-2: clamping plate, 2-3: heat sink, 2-4: photo-controlled thyristor, 2-5: disc spring. DETAILED DESCRIPTION

[0014] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0015] The commutation valve assembly of the light-controlled thyristor provided by the present invention is as follows: Figure 1 、 Figure 2 and Figure 3 As shown, it includes a component frame 1 with a shielding cover 4, a light-controlled thyristor component 2, a damping resistor and capacitor unit, a reactor component 3 and a water pipe; The component frame 1 is a steel structure frame, and the shielding cover 4 is fixed to the steel structure frame by screws. The component frame 1 is the mechanical support structure frame of the entire component. The light-controlled thyristor component 2 and the reactor component 3 are both assembled on the component frame and placed in the shielding cover; The light-controlled thyristor assembly 2 is arranged in a rectangular shape and mainly consists of an end plate 2-1, a clamping plate 2-2, a light-controlled thyristor 2-4, a heat sink 2-3, and a disc spring 2-5. The two end plates 2-1 and the two clamping plates 2-2 support and secure the light-controlled thyristor 2-4, the heat sink 2-3, and the disc spring 2-5. The twelve light-controlled thyristors 2-4 and the heat sink 2-3 are stacked and connected in series, that is, the light-controlled thyristors 2-4 and the heat sink 2-3 are arranged in intervals, with a heat sink 2-3 connected in series on each side of each light-controlled thyristor 2-4. The heat sinks 2-3 are connected at both ends of the entire light-controlled thyristor assembly. Each light-controlled thyristor is equipped with a thyristor voltage detection unit, namely a TVM circuit board, and the two are connected in parallel. The damping resistor-capacitor unit consists of a capacitor and a direct water-cooled resistor in series, connected in parallel with each thyristor; The reactor components 3 are symmetrically placed on both sides of the light-controlled thyristor components 2. Each thyristor component 2 is connected in series with two reactor components 3. The iron core and coil of the reactor are cast in an insulating shell. The heat generated by the reactor is directly cooled by the cooling water flowing through the coil duct. The water pipes mainly include the main water pipe, the branch water pipe in the valve assembly and the branch water pipe in the radiator connected to the branch water pipe in the thyristor assembly, and the water channels of the branch water pipe in the radiator are connected in parallel; in order to ensure that there is no voltage difference at both ends of the branch water pipe connecting the thyristor radiator and the branch water pipe, and to avoid electrical corrosion of the radiator due to electrolytic current, platinum electrodes are also installed at the branch water pipe positions at both ends of the light-controlled thyristor assembly.

Claims

1. A commutation valve assembly based on a light-controlled thyristor, characterized by: The assembly includes an assembly frame with a shielding cover, a light-controlled thyristor assembly, a damping resistor and capacitor unit, a reactor assembly, and a water pipe; The assembly frame is a steel structure frame, the shielding cover is fixed to the steel structure frame by screws, the assembly frame is the mechanical support structure frame of the entire assembly, the photothyristor assembly and the reactor assembly are both assembled on the assembly frame and placed in the shielding cover; The light-controlled thyristor assembly is arranged in a rectangular shape and mainly consists of an end plate, a clamping plate, a multi-stage series-connected light-controlled thyristor, a heat sink, and a disk-spring unit. The two end plates and the two clamping plates support and fix the light-controlled thyristor, the heat sink, and the disk-spring unit. The light-controlled thyristor and the heat sink are stacked and connected in series in sequence. The damping resistor and capacitor unit is composed of a capacitor and a direct water-cooled resistor connected in series, and is connected in parallel with each light-controlled thyristor; The reactor components are symmetrically placed on both sides of the thyristor components, each thyristor component is connected in series with two reactor components, the iron core and coil of the reactor are cast in an insulating shell, and the heat generated by the reactor is directly cooled by cooling water flowing through the coil guide tube; The water pipes mainly include a main water pipe, a branch water pipe in the valve assembly, and a branch water pipe in the radiator in the thyristor assembly connected to the branch water pipe.

2. A commutation valve assembly based on a light-controlled thyristor according to claim 1, characterized in that: The light-controlled thyristor assembly further includes a thyristor voltage detection unit TVM circuit board. Each light-controlled thyristor is equipped with a TVM circuit board and the circuit boards are connected in parallel.

3. The commutation valve assembly based on a light-controlled thyristor according to claim 1, characterized in that: The branch water pipes in the radiator are connected in parallel.

4. A commutation valve assembly based on a light-controlled thyristor according to claim 3, characterized in that: Platinum electrodes are installed at the water branch pipe positions at both ends of the light-controlled thyristor assembly.

5. A commutation valve assembly based on a light-controlled thyristor according to any one of claims 1 to 4, characterized in that: The disc spring unit in the light-controlled thyristor assembly is a disc spring.

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