An Over-Modulated Model Predictive Current Control for Permanent Magnet Synchronous Motors

Abstract

To improve the voltage utilization rate of DC bus and reduce the voltage vector tracking error, a finite-control-set modulated model predictive control (FCS-M2PC) with overmodulation capacity for permanent magnet synchronous motor (PMSM) incorporating penalty function is proposed in this paper. Firstly, three modulation regions are determined according to the combined action of dead-beat control and model predictive control (MPC). Secondly, three, two and one voltage vectors are applied to linear modulation region (LMR), overmodulation region I (OMR-I) and overmodulation region II (OMR-II), respectively, to synthesize the reference voltage vector. Thirdly, to obtain better steady-state performance in the whole modulation region, the optimal vector dwell-times can be obtained from the uniform penalty function defined by a set of mode parameters to minimize the error between the current references and the current predictions, rather than applying a single voltage vector in the conventional finite-control-set model predictive control (FCS-MPC). The effectiveness and superiority of the proposed method are validated experimentally.

Keywords

• Model predictive current control
• overmodulation
• penalty function
• dead-beat control
• steady-state performance