On-line monitoring method for dissipative current value in leakage current of lightning protector

Abstract

The present invention refers to resistance current value on-line monitoring method in lightning arrester leakage current. It contains firstly leakage total current signal ix (t), detecting said leakage total current signal (t) semiwave first peak value, and setting It as capacity current peak value ICP; secondly calculating resistance current IR through formula IR=Ix (t-ICP * cos { (-tcp) * 360 / }, to obtain resistance current value, wherein IR being resistance current, t being any time, tcp being corresponded ICP time, being total current cycle. The present invention can eliminate lightning arrester interphase disturbing influence, enhancing lightning arrester state monitoring validity for raising systems operation reliability.

Description

technical field [0001] The invention relates to an on-line monitoring method for leakage current of high-voltage electrical equipment in operation, in particular to an AC gapless metal zinc oxide arrester, which uses the analysis of the leakage current (also called full current) of the arrester to obtain resistive current An online detection method based on the value. technical background [0002] Zinc oxide arrester is a kind of protective equipment to protect electrical equipment from overvoltage. Due to the superior nonlinear characteristics and good flow capacity of the zinc oxide arrester, it has been accepted and widely used by users in the power sector. Damage and electrical accidents also occur, especially zinc oxide surge arresters with a voltage level of 110kV and above, once an accident occurs, it will cause huge losses to users. Therefore, on the basis of continuously improving the manufacturing level of arresters and ensuring the quality of arresters, actively...

AI Technical Summary

Problems solved by technology

Although this method can reflect certain valve aging problems, it is not so sensitive to other problems (such as internal moisture, partial discharge, etc.)

[0007] In addition, the resistive current of the MOA during operation is only tens of microamperes, and the signal coupled to the secondary detection circuit through the transformer is already extremely weak, while the electric field, magnetic field, and phase-to-phase interference of the high-voltage line in the substation are enough to produce a weak signal waveform. Difficult to overcome various influences, resulting in errors, offsets or instability in measurement results

Therefore, so far, there is no truly stable and reliable MOA resistive current monitoring technology recognized by the power industry.

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