Repulsion reversing valve for extra-high voltage series compensation bypass switch

Abstract

The invention provides a repulsion reversing valve for an extra-high pressure series compensation bypass switch, which comprises a valve body. A valve core is arranged in the valve body. The inside of the valve body is divided into a normally low pressure oil region, a working oil region, a normally high pressure oil region and a valve core moving region. The valve body is provided with a low pressure oil circuit connector, a working oil circuit connector and a high pressure oil circuit connector. A high pressure oil hole is arranged in the valve core. The right part of the valve body is provided with a repulsion valve. A drive rod of the repulsion valve is connected with the valve core. The middle part of the valve core is fixedly provided with a pressure maintenance wing. The pressure maintenance wing is always positioned in the working oil region and is arranged axially with the valve core. The reversing valve has the advantages of simple structure, high reliability, small volume, low cost, long service life and the like. When the reversing valve operates, the switching speed is high and the output characteristic is flexible. The static retentiveness of the reversing valve totally depends on the oil pressure. The bypass switch to which the reversing valve is adopted has closing time of 20ms to 25ms and breaking time of 26ms to 30ms. The technical requirement of an extra-high pressure series compensation device on the bypass switch can be totally met.

Description

technical field [0001] The invention relates to the field of a bypass switch for series compensation of a UHV AC power transmission test expansion project, in particular to a repulsion reversing valve for a 1000kV UHV series compensation bypass switch pioneered in the world. Background technique [0002] Since the reform and opening up, my country's economy has continuously maintained a rapid development momentum, and at the same time, the demand for electricity has continued to increase. According to the situation of my country's electricity supply and demand and energy distribution, urgent requirements have been put forward for the construction of UHV power grids. UHV transmission has the advantages of large capacity, long distance, low energy consumption, small land occupation, and good economy. In 2009, my country built the world's first Shandongnan-Jingmen 1000kV UHV AC transmission test demonstration project put into commercial operation. [0003] In order to give ful...

AI Technical Summary

Problems solved by technology

According to the experience accumulated in the actual use of the reversing valve, the following problems are likely to occur when the electromagnetic reversing valve is working: 1) Two opening and closing solenoid valves are required to control the movement of the spool to the left and right respectively, and the solenoid valve The opening and closing operation process and the control oil circuit are complex; 2) The solenoid valve and its conversion oil circuit have a small cross-section, so the cleanliness of the medium is high, and the medium containing particles often uses the solenoid valve and its conversion oil circuit. Blockage will eventually cause the solenoid valve to refuse to move, thereby affecting the action of the reversing valve; 3) There are many sealing links, low safety factor, and easy to cause external oil leakage; 4) Difficult maintenance, the spool of the reversing valve caused by the deposition of hydraulic oil pollutants Abnormal action, making the reversing valve invalid

However, there are still the following defects: 1) The opening and closing time of the hydraulic spring mechanism with this reversing valve is relatively long, because the action of the permanent magnet reversing valve needs to overcome the holding force produced by its own permanent magnet, which cannot meet the needs of UHV series compensation. Use the bypass switch to have special requirements for closing time ≤ 30ms; 2) Since the permanent magnet inside the permanent magnet valve is made of NdFeB permanent magnet material, its market price is relatively high, so the cost of the entire permanent magnet valve is relatively high

[0005] There is a common problem in the above existing reversing valves, that is, the completion time of the reversing valve action obtained from the solenoid valve or the permanent magnet valve coil is about 20ms (hereinafter referred to as the reversing valve action time). The opening and closing time of the bypass switch of the hydraulic spring operating mechanism of the reversing valve is relatively long, especially the closing time (the operating time of the reversing valve + the operating time of the piston rod of the operating mechanism) is 35ms-40ms, which is not suitable for special Requirements for Bypass Switches in High Voltage Series Compensation Engineering

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