针对动车组车载变压器油纸绝缘剩余寿命预测中单性能退化指标难以全面反映油纸绝缘退化过程的问题，考虑车载变压器油纸绝缘退化的个体差异性及两性能指标间的相关关系，提出了基于Copula函数的两性能指标相关退化的油纸绝缘剩余寿命预测方法:采用具有随机效应的维纳过程建立油纸绝缘的两性能指标相关退化模型，基于赤池信息准则(Akaike Information Criterion，AIC)选择拟合效果更优的Copula函数来描述两性能指标间的相关关系，采用最大似然估计法估计初始时刻的模型参数，基于序列贝叶斯更新方法在线更新退化模型中的漂移系数，以实现油纸绝缘剩余寿命的在线预测。最后以加速热老化试验下油纸绝缘的聚合度和抗拉强度的退化数据进行实例验证。结果表明，两性能指标相关退化模型比单性能指标退化模型的剩余寿命预测值与实际值之间的平均绝对误差更小，预测的准确性更高，且随着模型参数不断更新，剩余寿命的预测值与实际值间的绝对误差在不断减小，预测结果的准确性在不断提升。
Residual life prediction of oil-paper insulation for vehicle mounted transformer based on bivariate dependent degradation
To solve the problem that the single performance degradation index in the prediction of residual life of oil-paper insulation of vehicle-mounted transformer cannot fully reflect the degradation process of oil-paper insulation,considering the individual difference of oil-paper insulation degradation of vehicle-mounted transformer and the correlation of the two performance characteristics,a prediction method of residual life of oil-paper insulation based on bivariate dependent degradation was proposed.Firstly,a Wiener model with random effects was used to describe the degradation process of oil-paper insulation,and the drift coefficient in the model was randomized to characterize the randomness and individual differences of the degradation process of oil-paper insulation performance.Based on the Akaike Information Criterion(AIC)criterion,a Copula function with a better fitting effect was selected to describe the correlation between amphoteric energy indicators.Thus,a degradation model related to the zwitterionic energy index of oil-paper insulation is established,and the probability density function of its remaining life is derived;Then,the maximum likelihood estimation method is used to estimate the initial model parameters.The drift coefficient in the degradation model is updated online based on the sequential Bayesian update method to achieve online prediction of the remaining life of oil-paper insulation.Finally,the degradation data of the degree of polymerization and tensile strength of oil-paper insulation under accelerated thermal aging experiments are used for example verification.The results show that the average relative error of the residual life prediction value of the degradation model related to the gender performance index has always been smaller than the average relative error of the residual life prediction value of the single performance index degradation model.This result indicates that the residual life prediction results of the degradation model considering the gender performance index are more accurate than those of the single performance index degradation model.With increasing the operating time,the average relative error of residual life prediction values between the degradation model related to gender performance indicators and the single performance indicator degradation model is continuously decreasing,indicating that with the continuous updating of model parameters and residual life prediction results,the residual life prediction results are more accurate and the prediction accuracy is continuously improving.
safety engineeringtraction transformeroil-paper insulationbivariate Wiener modelCopula functionresidual life prediction
万方数据
维普
