Multispectral Optical Partial Discharge Detection, Recognition, and Assessment

In this article, a hypersensitive multispectral partial discharge (PD) optical sensor array was developed, by which the optical pulses in seven independent bands can be acquired simultaneously. By using this sensor array, the multispectral pulses for three typical PDs in gas insulated system were obtained experimentally and analyzed with phase-based (phase-resolved) and nonphase-based (spectral-ratio-based) multispectral characteristics, respectively. It indicates that the multispectral characteristics produced by a specific discharge defect provide unique spectral signatures in discharge mode as well as stage evolution. Based on the intrinsic relationship between the discharge feature and optical emission spectrum, we adopted the classification algorithms and spectral-ratio-reserved multispectral characteristics to implement pattern recognition as well as assessment on the three typical PDs, which obtained the hit ratios exceeding 91%. In principle, such detection approach also supports the phase-independent PD diagnosis especially for dc power equipment.