去极化电流解谱分析油纸绝缘等效电路参数研究

摘要

The dielectric response diagnosis technology is an effective method for diagnosing oil-paper insulation state, ensuring the reliability of the transformer’s operation and prolonging its lifespan. In order to further study the relation between the dielectric response characteristics and the insulation state change, indentifying the equivalent circuit parameter is needed. This paper improves the computing method by the spectrum analysis of depolarization current, estimates the time constant of each branch based on the time domain dielectric spectroscopy theory, and then calculates the polarization resistance and capacitance of each branch one by one. The method is easy and can reflect the physical significance. Finally, this method is applied to analyze three transformers and the error between calculated parameter and the original parameter is small, proving the method’s accuracy and feasibility.%介质响应法可以有效地判断油纸绝缘的状态，保证变压器运行的可靠性，延长老旧变压器的使用寿命。变压器油纸绝缘等效电路参数的求解对于深入分析介质响应特征量随绝缘状态变化的规律有重要意义。基于去极化电流解谱的方法对等效电路参数的求解进行了改进。根据时域介电谱理论，估算出各条支路的时间常数，再逐条求出每条支路的极化电阻、极化电容。该方法计算简单，而且还体现了物理意义。最后，用该方法对三台变压器进行解谱分析，计算得到的等效电路参数和原参数的误差很小，验证了该方法的有效性和可行性。