METHOD FOR DISTINGUISHING INITIAL TIME POINT OF ULTRA-HIGH-FREQUENCY PARTIAL DISCHARGE SIGNAL

摘要

The present invention relates to a method for positioning a space of an ultra-high-frequency partial discharge signal, and in particular, to a method for distinguishing an initial time point of an ultra-high-frequency partial discharge signal. The method comprises the following steps: a, triggering signal collection: setting a triggering level Vi of a signal, and when it is detected that a real-time voltage exceeds the triggering level Vi, triggering a signal collection system to start signal collection; and b, setting a triggering threshold of four-path waveforms: using the triggering level Vi as a threshold and a signal collection initial point, searching for a first peak value of the waveforms backwards, and further, searching for a first zero crossing point backwards as a wavefront time point of signals. By using a threshold method, the four-way waveforms are allowed to be not fully consistent with each other, which accords with a result of onsite detection of partial discharge signals. The threshold method is concise in computing, and does not need to reprocess the waveform signals, so that the initial time point is distinguished more accurately. In addition, when the zero crossing point is computed, the zero crossing point is gradually approached by performing quadratic interpolation for multiple times, and the accuracy of the time point of the zero crossing point is improved.