Switch cabinet partial discharge detection system resistant to transient pulse interference

Abstract

The invention discloses a switch cabinet partial discharge detection system resistant to transient pulse interference, and belongs to the technical field of partial discharge detection. The switch cabinet partial discharge detection system comprises a capacitance coupling module, a signal processing module and a shielding case, the shielding case is provided with a plurality of mutually independent shielding cavities, and the shielding cavities are communicated through wiring channels; the capacitive coupling module and the signal processing module are respectively installed in different shielding cavities, the capacitive coupling module and the signal processing module are connected through a cable, and the cable penetrates through the wiring channel. The capacitive coupling module and the signal processing module are installed in the shielding cavities which are isolated from each other, the influence of external noise signals and electromagnetic waves on the capacitive coupling module and the signal processing module can be effectively restrained, meanwhile, signal interference of different modules is reduced, and the accuracy of partial discharge detection is improved.

Description

technical field [0001] The invention belongs to the technical field of partial discharge detection, and relates to a partial discharge detection system of a switch cabinet against transient pulse interference. Background technique [0002] High-voltage switchgear occupies a very important position in the power supply and distribution system, and its operational reliability directly affects the safety of the power supply system. During the operation of the switchgear, due to the inevitable influence of various factors such as electricity, heat, machinery and the environment, its insulation medium continues to deteriorate, resulting in poor operating conditions, and even various failures, causing local or even large-scale power outages. Cause huge direct and indirect economic losses and social impact. There are many reasons for the deterioration of the insulating medium, such as ionization corrosion caused by long-term strong electric field, insulation wear caused by high-fre...

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Problems solved by technology

For the discharge inside the switchgear, the discharge electricity gathers on the inner surface of the ground shield. If the shield is continuous, the discharge signal cannot be detected externally, but in fact, the shield is usually at the insulation part, the gasket connection, the cable insulation The terminal and other parts are damaged and discontinuous, so that the electromagnetic wave generated by the partial discharge will be transmitted to the surface of the equipment through the discontinuous part of the shielding layer, and an induced current will be generated on the surface of the equipment. There is a wave impedance on the surface of the equipment, and then a Transient voltage to ground (referred to as TEV)

[0004] The amplitude and discharge frequency of partial discharge can be obtained by coupling the voltage signal with a capacitive sensor. This is also one of the main methods of TEV detection at present, but there are a large number of electromagnetic signals in the work site, and electromagnetic interference has a great impact on TEV detection. It cannot be used as a means of quantitative measurement, and only relative readings can be used to express the discharge intensity. Therefore, the use of this method is limited, and it is mainly used for comparative measurements, comparing the operation of each equipment in a certain group of specific equipment to determine The first order of maintenance, or track and measure a single device in time, find out the change of its discharge activity, and understand the damage of the device

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