CN-115560539-B - Converter valve cooling system waterway for inhibiting leakage current of equalizing electrode

CN115560539BCN 115560539 BCN115560539 BCN 115560539BCN-115560539-B

Abstract

The application provides a converter valve cooling system waterway for inhibiting leakage current of a voltage-sharing electrode, which comprises an anode valve section, a cathode valve section and a cooling water pipe, wherein the anode valve section and the cathode valve section are respectively arranged at two sides of the cooling water pipe and are communicated with the cooling water pipe, the anode valve section and the cathode valve section comprise a plurality of aluminum radiators which are connected in parallel, voltage-sharing electrodes are arranged at two ends of a secondary aluminum radiator from the head end and the tail end of the cathode valve section and the anode valve section, and the voltage-sharing electrodes at two ends are connected through an equipotential line. The application changes the voltage-sharing electrode originally connected with the head-end aluminum radiator at the position connected with the secondary aluminum radiator, and can obviously reduce the leakage current of the voltage-sharing electrode by changing the position of the voltage-sharing electrode of the thyristor component so as to avoid scaling of the voltage-sharing electrode.

Inventors

WANG RUI
LI YONGLI
WU HUACHENG
LI CHAO
LI PENG

Assignees

华北电力科学研究院有限责任公司
国家电网有限公司

Dates

Publication Date: 20260508
Application Date: 20221027

Claims (5)

1.A converter valve cooling system waterway for suppressing leakage current of a equalizing electrode, comprising: an anode valve section, a cathode valve section and a cooling water pipe; the anode valve section and the cathode valve section are respectively arranged at two sides of the cooling water pipe and are communicated with the cooling water pipe; The anode valve section and the cathode valve section comprise a plurality of aluminum radiators which are connected in parallel, and thyristors are arranged between the aluminum radiators; The two ends of the secondary aluminum radiator which are respectively started from the head end and the tail end of the cathode valve section are provided with voltage-equalizing electrodes, the two ends of the secondary aluminum radiator which are respectively started from the head end and the tail end of the anode valve section are provided with voltage-equalizing electrodes, and the voltage-equalizing electrodes at the two ends of each secondary aluminum radiator are connected through equipotential lines; wherein two collecting pipes are respectively extended at two sides of the cooling water pipe, namely a water inlet collecting pipe and a water outlet collecting pipe; The water inlet collecting pipe is connected with a water inlet branch pipe of the aluminum radiator; the water outlet collecting pipe is connected with a water outlet branch pipe of the aluminum radiator.
2. The converter valve cooling system waterway for suppressing leakage current of equalizing electrode according to claim 1, wherein 14 aluminum radiators are included in the cathode valve segment and the anode valve segment, respectively.
3. The converter valve cooling system waterway for inhibiting leakage current of equalizing electrode according to claim 2, wherein the two valve segments form a 6-pulse current converter in a conducting manner of a common cathode and a common anode.
4. A converter valve cooling system waterway for suppressing leakage current of equalizing electrodes according to claim 3, characterized in that each phase thyristor equalizing electrode follows the same potential variation law in one 2 pi period.
5. The water channel of the converter valve cooling system for inhibiting leakage current of voltage equalizing electrodes according to claim 4, wherein the 6-pulse current converter is formed by series-parallel connection of thyristors of basic units.

Description

Converter valve cooling system waterway for inhibiting leakage current of equalizing electrode Technical Field The application belongs to the technical field of electric power, and particularly relates to a converter valve cooling system waterway for inhibiting leakage current of a voltage-sharing electrode. Background The converter valve is core equipment of an extra-high voltage direct current transmission project, and the three alternating voltages are sequentially connected to a direct current end to obtain expected direct current voltage, so that the power is controlled. The thyristor assembly is a basic unit for forming a converter valve, the thyristor is core equipment of the thyristor assembly, heat is generated during operation, and the thyristor fails when the temperature exceeds the junction temperature of the thyristor, so that the thyristor needs to be cooled. As shown in fig. 1, taking a conventional cooling waterway of a thyristor assembly as an example, the thyristor assembly is formed by connecting two valve segments in series, and each valve segment comprises 13 thyristors and corresponding accessories. The assembly adopts a cooling system in a parallel waterway mode, the cathode side and the anode side of each thyristor are in close contact with the aluminum radiator, the water inlet pipe and the water outlet pipe of each aluminum radiator are connected with a converging waterway, the internal cooling water system takes away heat generated during the work of the thyristor through the aluminum alloy radiator by a plurality of branch small waterways through an inlet and outlet converging water pipe, and the aim of cooling is achieved. In order to prevent electrochemical corrosion of the aluminum radiator, a pressure equalizing electrode is generally arranged in a water path of the converter valve cooling system. The equalizing electrode is a cylindrical metal piece arranged in the cooling water inlet and outlet converging water pipe, and the head part is an arc-shaped end surface. The adjacent aluminum radiators are connected through the voltage equalizing electrodes, so that the potentials of the radiators are consistent with the potentials of the corresponding positions of the collecting pipes, the electrochemical corrosion of leakage current generated in the radiators to the surfaces of the radiators is avoided, the operation protection of an internal cooling water system is realized, and the installation positions are shown in figure 1. However, in recent years, faults of the cooling waterway system frequently occur, and huge economic losses are caused. After inspection, it was found that the scaling of the pressure equalizing electrode in the cold water system in the converter valve is one of the main causes of the above faults. Research results show that scaling products are derived from corrosion of an aluminum radiator of a converter valve cooling system, scaling substances mainly comprise hydroxy aluminum stones, the scaling substances are formed by the fact that electric field force formed by a positive potential voltage-sharing electrode under an alkaline condition attracts negative ions Al (OH) 4- to react on the surface of the electrode, and the positive potential is formed by the fact that the voltage-sharing electrode is opposite to earth leakage current, so scaling of the voltage-sharing electrode can be effectively avoided by controlling the generation of leakage current. Disclosure of Invention The application provides a converter valve cooling system waterway for inhibiting leakage current of a voltage-sharing electrode, which at least solves the problem of frequent faults caused by the structure of the voltage-sharing electrode of the current converter valve cooling waterway system. According to the present application, there is provided a converter valve cooling system waterway for suppressing leakage current of a voltage equalizing electrode, comprising: an anode valve section, a cathode valve section and a cooling water pipe; the anode valve section and the cathode valve section are respectively arranged at two sides of the cooling water pipe and are communicated with the cooling water pipe; The anode valve section and the cathode valve section comprise a plurality of aluminum radiators which are connected in parallel; And the two ends of the secondary aluminum radiator from the head end and the tail end of the cathode valve section and the anode valve section are provided with equalizing electrodes, and the equalizing electrodes at the two ends are connected through an equipotential line. In one embodiment, the anode valve segment includes a plurality of aluminum heat sinks connected in parallel with thyristors disposed between the aluminum heat sinks. In one embodiment, the cathode valve section includes a plurality of aluminum heat sinks connected in parallel with thyristors disposed between the aluminum heat sinks. In one embodiment, two collecting pipes, namely a