Ultra-high-voltage series compensation device

Abstract

The invention provides an ultra-high-voltage series compensation device which comprises a series capacitor, a first metal oxide voltage limiter (MOV) and at least two discharge branches, wherein the series capacitor is connected in series with an ultra-high-voltage power transmission line; the first MOV is connected in parallel with two ends of the series capacitor; each discharge branch is connected in parallel with two ends of the series capacitor to form a path of discharge current of the series capacitor. The discharge branches of the series capacitor are added to inhibit discharge current for series compensation, and the addition of the discharge branches is equivalent to the addition of damped inductors, so that the discharge current is reduced. Under the same parameters and voltage of the series capacitor, the amplitude of the discharge current of the series capacitor passing through components such as a spark gap and the damped inductors is reduced. On the ultra-high-voltage power transmission line, the research and development difficulties of the spark gap for series compensation can be lowered, the recovery time of insulation property of the spark gap can be shortened, the reuse time of the series capacitor after fault occurrence can be shortened, and the stability of an ultra-high-voltage power transmission system is improved.

Description

technical field [0001] The invention relates to the technical field of transmission line compensation, in particular to an UHV series compensation device. Background technique [0002] The series compensation device is to connect capacitors in series in the transmission line, and the capacitance compensation of the capacitor is used to compensate the inductance of the transmission line to shorten the equivalent electrical distance of the line, reduce the voltage drop and power angle difference caused by power transmission, and improve the power system. Stability, increase line transmission capacity. [0003] At present, the series compensation device used in the ultra-high voltage transmission line, the spark gap discharge current does not exceed 120kA, which can meet the requirements of the existing equipment design, test and manufacturing capabilities. [0004] However, when the voltage rises to the UHV level, the existing research shows that when this structure is adopte...

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Problems solved by technology

[0004] However, when the voltage rises to the UHV level, the existing research shows that when this structure is adopted, when the most serious intra-area fault occurs on the UHV transmission line, the maximum discharge current of the series-compensated spark gap can exceed 150kA. The series compensation device used in the EHV transmission circuit will not be suitable for the UHV transmission circuit

[0005] Since the series compensation spark gap is an air gap, the higher the discharge current amplitude is, the more serious the ablation of the gap electrode will be during discharge, and the higher the heat generated in the space where the gap electrode is located, the slower the recovery speed of the gap’s insulation performance. , the ability to withstand the breakdown voltage is reduced, which prolongs the time interval for re-introducing the series compensation capacitor after the line fault disappears. In addition, the spark gap discharge current is too large, which will also cause great difficulties in the design, manufacture and type test of the spark gap equipment.

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