An FCS-MPC-based open-circuit and current sensor fault diagnosis method for traction inverters with two current sensors

Abstract

Effective fault diagnosis methods can improve the reliability of the two-level inverter used in traction systems. Both the open-circuit (OC) fault and current sensor fault can affect the phase currents of the inverter, which makes it difficult to distinguish them. In this paper, a diagnosis method for OC faults and current sensor faults is proposed, which is based on finite control set-model predictive control (FCS-MPC). First, the cost function is constructed and the inverter is controlled by the FCS-MPC. Then, the actual and estimated values of the cost function are calculated. The difference between them is applied to fault detection. Next, Combine the command signals and current direction, the number of affected sampling points in a period is counted and normalized. Different faults correspond to different percentages and this feature is used to determine fault location. Finally, the hardware-in-the-loop (HIL) platform is built, the feasibility and effectiveness of the proposed fault diagnosis method are verified by the HIL tests.