Model predictive current control of three-phase PMSM based on four-leg inverter

The reliability of three phases Permanent Magnet Synchronous Motors (PMSMs) determines the electric drive system's performance because the three phases PMSM still occupies the predominant position. Applying a three phases four-leg inverter is a feasible way to achieve fault-tolerant operation for three-phase motors. However, the introduction of redundant arms increases control complexity and difficulty. It is difficult for Proportional-Integral (PI) controller to accurately tracks the zero-axis current target after the single-phase fault. This paper implements the Model Predictive Current Control (MPCC) method to solve this problem. In the first place, the mathematical models of four-leg topology and PMSM are established. In addition, the pulse width modulation strategy and time-discrete predictive control model are investigated. Finally, a simulation case study of three-phase PMSM based on a four-leg inverter is conducted. Compared with PI control, MPCC can have a faster dynamic response and reduce phase current harmonics by 55.3%. The application of MPCC can make the PMSM respond faster after an Open-Phase Fault (OPF) occurs to ensure the stable operation of the electromagnetic drive system.