棒/球-板长间隙的电场分布特征与操作冲击放电电压预测

Electric Field Distribution Features and Switching Impulse Discharge Voltage Prediction of Long Rod/sphere-plane Gaps

空气间隙的电场分布是决定其绝缘强度的重要因素,建立电场分布特征与放电电压的关联性是实现绝缘计算的关键.该文针对棒-板和球-板长间隙,提出一种空间电场分布表征方法,对电场有限元仿真结果进行后处理,从极间路径和锥形场域中提取66个特征量.建立基于最小二乘支持向量机的预测模型,以电场分布特征集和放电电压作为输入和输出参数,通过改进灰狼算法对模型进行参数优化,利用最大信息系数法进行特征降维.采用该模型对棒/球-板长间隙进行标准操作冲击放电电压预测,算例结果表明,测试样本预测值与试验值较为吻合,最大相对误差为8.3%,平均绝对百分比误差为3.2%.研究结果可为实现空气间隙绝缘计算提供参考.

This paper proposes a method to characterize the spatial electric field distributions of long rod-plane and sphere-plane gaps.The finite element simulation result of the electric field was post-processed,and 66 feature quantities were extracted from the interelectrode path and a conical region.A prediction model was established based on the least squares support vector machine(LS-SVM),taking the electric field distribution feature set and the discharge voltage as input and output parameters.The improved grey wolf optimizer was used to optimize the model parameters,and the feature dimension was reduced by the maximal information coefficient method.This model was applied to predict the standard switching impulse discharge voltages of long rod-plane and sphere-plane gaps.The results of the case study indicate that the predicted values of test samples are in good agreement with the experimental values,with a maximum relative error of 8.3%and the mean absolute percentage error of 3.2%.This study can provide references for air gap insulation calculation.