单气隙局部放电仿真模型的修正与关键参数的确定

Study on Modifying the Simulation Model and Computating the Key Parameters of Partial Discharge in Single Void

针对目前国内外局部放电仿真模型不能客观反映局部放电物理过程的问题,提出了一种单气隙局部放电仿真模型的修正方法,并确定了影响仿真结果的一些关键参数.该修正方法将气隙分为气隙绝缘电阻和气隙沿面绝缘电阻,引入了气隙沿面半导电化过程,并在仿真计算中考虑了气隙放电的时间过程以及放电的电子雪崩过程.根据放电的实际物理过程,应用工程近似计算方法,确定了仿真模型中放电起始电压、放电熄灭电压和气隙等效电阻、等效电容等关键仿真参数,从而使仿真模拟接近于绝缘试样中气隙实际放电过程,仿真得到的气隙局部放电波形不同于国外仿真得到的锯齿波,十分接近于实际测量波形,为深入开展局部放电仿真研究奠定了基础.

Because the existing simulation model of partial discharge (PD) in the world cannot describe its physical inherence objectively, a modified simulation model of PD in a single void is proposed, and some key parameters of this model are determined. This modified model divides the void resistance into gas-gap resistance and interface resistance. The semi-conductive process of the interface resistance is introduced in this model. The time process of discharges and the process of electron avalanche are also considered. According to the physical inherence of PD, some key parameters are calculated approximately so that the simulation is much closer to the real discharge process of voids in insulation samples. These key parameters include the discharge inception voltage, the discharge extinction voltage, the equivalent resistance, and capacitance of a single void. The simulation results are different from the saw-tooth waves obtained by foreign researchers and are much similar to the measured waveforms, which is the foundation of further studies on the simulation of PD.