电力系统保护与控制2025，Vol.53Issue(2)：73-88,16.DOI:10.19783/j.cnki.pspc.240254
基于模态时频图与Resnet-BiGRU模型的MMC子模块开路故障诊断
Open-circuit fault diagnosis of MMC sub modules based on modal time-frequency diagrams and the Resnet-BiGRU model
摘要
Abstract
There are problems of easy omission of extracted feature information,low diagnostic accuracy and large computation volume in the fault diagnosis process for the modular multilevel converter(MMC)in power systems.Thus a discretized MMC open-circuit fault diagnosis method with modal time-frequency diagrams and Resnet-BiGRU model is proposed.From the open-circuit fault characteristics,the output phase currents and bridge arm voltages are selected as fault parameters.The improved gray wolf optimization algorithm is used to search the optimal parameters in the process of complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN).Combined with the optimal parameters of CEEMDAN,the fault parameters are decomposed into sensitive and high-quality intrinsic mode function(IMF)components and reconstructed.To fully exploit the sensitive components in the reconstructed signals,those signals are transformed into modal time-frequency diagrams using continuous wavelet transforms;the modal time-frequency diagrams in different fault categories are input to the Resnet-BiGRU model for training,testing and outputting the diagnostic results,so as to complete the diagnosis of the faulty bridge arms and the localization of the faulty IGBT in the sub modules.The experimental results show that:its diagnosis of faulty bridge arms and localization of faulty IGBT in the sub modules reach an accuracy of 98.63%and 99.87%,with high diagnostic accuracy;the diagnostic process possesses a response time of seconds;compared with other methods,the proposed method has a higher accuracy in extreme conditions such as small samples,data imbalance,and noise interference.The work provides a new way for the diagnosis of power system faults.关键词
模块化多电平换流器/开路故障诊断/模态时频图/Resnet-BiGRU模型Key words
modular multilevel converter/open-circuit fault diagnosis/modal time-frequency diagrams/Resnet-BiGRU model引用本文复制引用
刘述喜,刘科,王乾蕴,曲雨霏,罗钦..基于模态时频图与Resnet-BiGRU模型的MMC子模块开路故障诊断[J].电力系统保护与控制,2025,53(2):73-88,16.基金项目
This work is supported by the National Natural Science Foundation of China(No.52207004). 国家自然科学基金项目资助(52207004) （No.52207004）
重庆市教委科学技术研究计划项目资助(KJQN202001128) （KJQN202001128）
