摘要
Introduction:With the development of flexible HVDC technology,the fault diagnosis of MMC-HVDC becomes a new research direction.Based on the fault diagnosis theory,this paper proposes a robust fault diagnosis method to study the fault diagnosis problem of MMC-HVDC systems.Methods:By optimizing the gain matrix in the fault observer,fault detection with good sensitivity and robustness to disturbance is achieved.In the MMC-HVDC system,because of the inherently uncertain system and the presence of various random disturbances,the study of robust fault diagnosis method is particularly important.Results:Simulation studies during various AC faults have been carried out based on a 61-level MMC-HVDC mathematical model.The results validate the feasibility and effectiveness of the proposed fault diagnosis method.Conclusions:So this fault diagnosis method can be further applied to the actual project,to quickly achieve system fault diagnosis and accurately complete fault identification.
