Fault Detection of Modular Multilevel Converter with Kalman Filter Method

Abstract

In this paper, the fault detection problem of the modular multilevel converter (MMC) system is investigated with kalman filtering method. Based on the running rules of the circulating current and output current for the MMC system, the state-space model is established and the estimation both of the circulating current and the output current are realized by using the kalman filtering theory. By collecting the predicted and measured values of circulating current and the output current, the residual can be achieved by using the difference between them. Nextly, the residual estimation function and its threshold are constructed, then the fault can be detected according to the proposed fault detection strategy. Finally, 11 levels of MMC simulation system in MATLAB/Simulink is set up, the effectiveness of the proposed fault detection method is verified.