Automatic Blind Equalization and Thresholding for Partial Discharge Measurement in Power Transformer

作者：Chan Jeffery C^*; Ma Hui; Saha Tapan Kumar

来源：IEEE Transactions on Power Delivery, 2014, 29(4): 1927-1938.

DOI：10.1109/TPWRD.2014.2322114

• Blind equalization (BE)
• de-noising
• mathematical morphology (MM)
• partial discharge (PD)
• phase-resolved pulse sequence (PRPS)
• transformer

Partial discharge (PD) signals acquired from on-line measurements of power transformers are easily overwhelmed by various interference and noise. This paper proposes an automatic blind equalization (BE) and morphological thresholding method for PD signal de-noising. Firstly, BE automatically selects an equalized signal that reveals PD impulses from an acquired noise-corrupted signal. Then, automatic morphological thresholding (AMT) is adopted for determining thresholds on the equalized signal. After de-noising with BE and AMT, phase-resolved pulse sequence (PRPS) is constructed and used for analyzing the types of insulation defects that cause discharges. To verify the proposed method, PD measurements on experimental PD models and a distribution transformer have been conducted. The results show that PD impulses can be extracted from severely noise-corrupted signals by using the proposed method. Also, PRPS constructed from de-noised signals can achieve consistency in revealing the types of insulation defects even different types of PD sensors and measurement systems are used.

• 出版日期2014-8