Integrated Virtual Voltage Vectors and Duty Cycle Control to Minimize the Current Ripples in Finite Control Set Model Predictive Control for Permanent Magnet Synchronous Motor Drives

Abstract

Finite Control Set Model Predictive Control (FCSMPC) is widely acknowledged as a simple and effective control scheme for permanent magnet synchronous motor (PMSM) drives. It delivers the merit of quick dynamic response however faces problems such as large current ripples and unsatisfactory steady state performance. This paper proposes a FCSMPC method which minimizes the current ripples by integrating the concept of duty cycle and virtual voltage vectors. In the proposed method, six symmetrically positioned virtual voltage vectors are introduced in addition to the six original active voltage vectors to expand the finite control set, among which one optimal vector is selected and applied in each sampling interval according to the enumeration-based principle of cost function minimization. Then, the duration of the optimal vector is decided by an efficiently calculated duty ratio. Compared to the conventional FCSMPC, the proposed method causes no additional computation burden but exhibits much lower current ripples. The proposed method is experimentally compared with two typical FCSMPC methods for an interior permanent magnet synchronous machine and it is proved that the proposed method delivers better steady-state performance while maintaining quick dynamic response.