局部放电的数学模型和频域特性

FREQUENCY-DOMAIN CHARACTERISTICS AND MATHEMATICAL MODEL OF PARTIAL DISCHARGES

本文建立了描述电介质材料内部局部放电动态过程的数学模型.首先采用Laplace 变换和数值计算法得到了放电电脉冲的时域特性.由于表达式中不少参数是时间的隐函数,本文运用非线性拟合和数值计算,又从放电脉冲的时域特性获得了相应的频域特性,计算结果与本文采用宽频带频谱测试所得的放电脉冲频域特性基本相符,且变化趋势相同.证实了所建立的局部放电数学模型是合理的,以此研完局部放电的频域特性及其动态过程是有效的.

In this paper a mathematical model for describing dynamic processes of partial discharges in dielectric materials Was set up based on the hypothetical and approximate conditions(?)Laplace transformation and numerical calculating me- thods were adopted to get the time-domain characteristies of ele(?)trical pulses of internal,discharges.The non-linear ourve fitting technique and numerical cas- culating methods were used to obtain the corresponding frequency-domain chara- cteristics.The calculated results were in basic agreement with the measures froquency-domain characteristics of internal discharges by means of wide band frequency spectrum analyzer,and both had the same varying tendency.All this confirmed that the mathematical model of partial discharges was reaso- nable and it was very convenient and fruitful to investigate frequency-domain charac eristics and their relationships with dynamio processes of partial pischar- ges.