Parameters Identification and Application of Equivalent Circuit at Low Frequency of Oil-paper Insulation in Transformer

Yiming Xie, Jiangjun Ruan
2020 IEEE Access  
The low frequency section of frequency domain spectroscopy (FDS) of oil-paper insulation system can effectively reflect the ageing state and moisture of the oil-immersed paper. Meanwhile, steady-state insulation resistance is the one of indexes for the condition of transformer. In actual measurement, these two both are time-consuming and poor accessibility, thereby restraining their field applications. Aim at this problem, this paper analyses the polarization process of the oil-paper insulation
more » ... il-paper insulation in transformer, and adopts a low frequency equivalent circuit model for the oil-paper insulation to characterize the polarization process at low frequency. The simulated annealing particle swarm optimization (SAPSO) algorithm is proposed to identify the parameters in equivalent circuit, which are affected by change of insulation state. Compared with the experimental results, the errors of the steady-state insulation resistance and the tan δ below 10 −3 Hz, which are calculated by the identified parameters, are less than 2.5%. This method can avoid the influence from external environment and reduce the measurement time. The time and frequency domain parameters calculated can provide reference for the ageing assessment of oil-immersed paper. INDEX TERMS Oil-paper insulation equivalent circuit, interfacial polarization, simulated annealing particle swarm optimization, steady-state insulation resistance, frequency domain spectroscopy. VOLUME 8, 2020 This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/
doi:10.1109/access.2020.2992681 fatcat:7kc7w4k475arrk42oejc2gagxy