分布式光伏接入对配电网接地故障影响分析及其故障辨识研究OA

A large number of distributed photovoltaic access changes the traditional distribution network structure and power flow,and changes the grounding fault characteristics of the distribution network.By analyzing the influence of grid-connected capacity,location,photovoltaic output fluctuation and grid-connected high harmonics on zero-sequence voltage of grounding faults,it is found that various time-frequency domain characteristics of zero-sequence voltage are affected to different degrees,and even some ground faults are confused in time-frequency domain,which makes fault identification more diffi-cult.The ground fault identification algorithm of VMD-MPE-CNN based on zero sequence voltage is proposed.Firstly,the zero-sequence voltage signal is decomposed by VMD-MPE algorithm,and the multi-scale arrangement entropy of eigenmode components is calculated to obtain the fault characteristic matrix.Then,the CNN structure is constructed and the feature matrix of various fault samples is used for training,and finally the ground fault classification and identification model based on VMD-MPE-CNN is formed.Experiments show that the algorithm based on VMD-MPE can effectively differentiate various fault features,and compared with the traditional time-frequency feature identification model,the fault i-dentification accuracy of the proposed model is improved.