Half-peak periodic polarization spectrum analysis of oil-paper insulated transformer based on recovery voltage method
Cai Chao1, Liu Qingzhen1, Fan Ying2, Gao Hao1
1. College of Electrical Engineering and Automation, Fuzhou University, Fuzhou 350108; 2. Fujian Electric Power Co., Ltd, Maintenance Branch Company, Fuzhou 350013
Abstract：The traditional characteristic of recovery voltage can not reflect the polarization characteristics of recovery voltage in the middle and late stages. Based on this, a new characteristic of RVM, half-peak periodic stability time, which can effectively reflect the relaxation characteristics in the middle and late stages of RVM, is proposed in this paper. Firstly, an extended Debye equivalent simulation model is established to draw the half-peak periodic polarization spectrum of recovery voltage, from which the half-peak periodic polarization spectrum of recovery voltage is extracted. Then, the influence of circuit parameters of transformer equivalent model on half-peak periodic polarization spectrum is discussed. Finally, the inference is verified by the measured data of several transformers. The results show that the half-peak period stability time increases with the aging of oil-paper insulation, which is mainly affected by medium and large time constant branches. It is universal for transformers of different specifications and can be used as a good feature for subsequent insulation diagnosis.
2020, Vol. 21 
