An Improved Mathematical Model for Estimating Polarization Parameters of Transformer Oil-Paper Insulation

作者：Zhang, Tao^*; Mandala, Antonio Tome; Zuo, Qian; Zhang, Ning; Jiang, Shijie

来源：Journal of Electrical Engineering & Technology, 2022, 17(4): 2517-2525.

DOI：10.1007/s42835-022-01019-0

• Transformer
• Oil-paper insulation
• Recovery voltage method
• Improved mathematical model
• Particle swarm optimization algorithm

The parameters of dielectric response based on extended Debye circuit model can reflect oil-paper insulation state. The model using the initial slop of recovery voltage to estimate circuit parameters, serve as good quality consistency with the measured data. However, the model can be applicable for large power transformers but not for distribution transformers. This paper proposed an improved mathematical model using recovery voltage peak, peak time and initial slope characteristics to solve dielectric response equivalent circuit parameters. The identification of equivalent circuit parameters is converted into a mathematical optimization problem. And then particle swarm optimization algorithm is used for solving the problem. The improved mathematical model can decrease sampling data of recovery voltage. To check the validity of the estimated parameters, the on-site measured data of RVM experiments on actual transformers in various capacities is applied. The calculated result shows that the recovery voltage curve calculated and measured recovery voltage curve have good consistency, which can be advantageous to diagnose the oil-paper insulation status of transformer. It illustrates that the improved method proposed in this paper is feasible and effective.