Long-air-gap spherical electrode streamer discharge simulation system and simulation method thereof

Abstract

The invention discloses a long air gap spherical electrode streamer discharge simulation system. The system comprises an impulse voltage generator, a voltage divider, a spherical experimental electrode, a galvanized electrode plate, a high-potential transient current measuring device, an electric field sensor, a photomultiplier, a high-speed camera, an oscilloscope and an analog terminal, whereinthe impulse voltage generator and the voltage divider are electrically connected with each other; and the spherical experimental electrode is electrically connected with the voltage divider, the galvanized electrode plate is grounded, and the analog terminal is in communication connection with the high-potential transient current measuring device, the electric field sensor, the photomultiplier, the high-speed camera and the oscilloscope. The defects in the prior art can be overcome, a ball-plate gap dynamic streamer fractal development model based on charge accumulation is established, and a guide mechanism of generation, accumulation and dissipation of space charges of a discharge channel on discharge development is conveniently researched.

Description

technical field [0001] The invention relates to the technical field of electric equipment fault diagnosis, in particular to a long air gap spherical electrode streamer discharge simulation system and a simulation method thereof. Background technique [0002] In EHV / UHV DC projects, the valve hall of the converter station has always been the focus of cooperation in engineering design, complete sets of equipment, construction and installation, etc. The selection of the insulation distance of the internal air gap is directly related to the safe and stable operation of the DC project. Engineering investment. In the past, in order to ensure a sufficient safety margin in DC projects, the insulation distance of the air gap in the valve hall was relatively large, resulting in a corresponding increase in related investment costs. However, with the increase in the operating voltage of DC projects, the discharge voltage of 50% of the gap and the gap distance showed obvious saturation. ...

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Problems solved by technology

[0004] Scholars at home and abroad have carried out systematic research on typical gap structures such as rod-plate and rod-rod, and obtained relevant characteristic parameters such as electric field, current and temperature field in the process of discharge development. However, for spherical electrodes, especially large-diameter spherical electrodes, As the radius of curvature of the electrode increases, the critical volume of the streamer discharge also increases accordingly. At the same time, more charges are generated by ionization in the discharge channel. The initial field strength of the initial streamer and the distribution of space charges in the discharge channel have changed. The existing streamer initiation criterion is no longer applicable to the large-diameter ball-plate gap. There is a big difference between the experimental test results and the theoretical analysis.

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