Method for estimating the initial phase of partial discharge in the positive half cycle of power frequency voltage on vehicle cables

Abstract

The invention discloses a method for estimating power frequency voltage positive half cycle partial discharge initial phases of a vehicle-mounted cable at low temperature. The method is mainly applicable to a low-temperature partial discharge test process for a vehicle-mounted cable in a laboratory, and estimates to obtain the power frequency voltage positive half cycle partial discharge initial phases of the vehicle-mounted cable at low temperature. The method comprises the specific steps of: 1) acquiring partial discharge development time t; 2) judging a partial discharge development phase S; 3) and estimating the power frequency voltage positive half cycle partial discharge initial phases of the vehicle-mounted cable at low temperature. The method has the beneficial effect of being conductive to studying the power frequency voltage positive half cycle partial discharge features of the vehicle-mounted cable at low temperature in the laboratory, and evaluating the insulation performance of the vehicle-mounted cable in a low temperature environment.

Description

technical field [0001] The invention belongs to the field of partial discharge of vehicle-mounted cables under low-temperature environment, and in particular relates to a method for estimating the initial phase of partial-discharge in the positive half cycle of power-frequency voltage of vehicle-mounted cables under low temperature. Background technique [0002] With the rapid development of my country's high-speed railways, EMU trains are increasingly operating in severe cold areas with very harsh environmental conditions (such as Northwest and Northeast regions). On-board cables are the most critical part of high-voltage equipment for high-speed EMUs and electric locomotives. The role of EMUs or locomotives in connecting various high-voltage equipment and transmitting electric energy is irreplaceable. [0003] The EMU train contains two pantographs, but a single pantograph is put into operation during the normal operation of the EMU, and the other pantograph is in a standb...

AI Technical Summary

Problems solved by technology

The on-board cables that pass all the test indicators at room temperature frequently suffer from partial discharge breakdown faults during low-temperature operation, which will not only cause huge economic losses, but also endanger driving safety. Therefore, it is urgent to carry out relevant research on the insulation evaluation of on-board cables at low temperatures

According to practical engineering problems, the low-temperature partial discharge experiment for on-board cables is one of the insulation evaluation studies that must be carried out. The initial phase of partial discharge in the positive half cycle of the power frequency voltage of on-board cables is the main parameter of partial discharge experiments. This greatly limits the evaluation of the insulation performance of vehicle cables in low temperature environments, so there is an urgent need for a method for estimating the initial phase of partial discharge in the positive half cycle of power frequency voltage of vehicle cables at low temperatures

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