Fault Tolerant Predictive Control of Three-Level Neutral-Point-Clamped Back-to-Back Power Converters

This paper presents a fault diagnosis and fault-tolerant control method for open-circuit fault in three-level neutral-point-clamped back-to-back power converters. The proposed fault diagnosis method is based on analysis of probability distribution of stator current. No extra sensor is needed. Additionally, fault detections for both one- and two-phase open-circuit fault are achieved. The proposed fault-tolerant control scheme is a non-redundant solution and is embedded into the well-known model predictive control (MPC) frame. Simulation results validate the feasibility and effectiveness of the proposed fault diagnosis and fault-tolerant control methods.