An Indirect Reference Vector-Based Model Predictive Control for a Three-Phase PMSM Motor

Shuangxia Niu,Yixiao Luo,Xiaodong Zhang,Weinong Fu

doi:10.1109/access.2020.2968949

Abstract

Almost all of the existing reference vector based finite control set-model predictive control (FCS-MPC) methods for electric machines adopt the deadbeat control principle to directly obtain the reference vector. This paper proposes a computationally efficient control approach for a three phase permanent magnet synchronous motor (PMSM) based on indirect reference vector without using the deadbeat control. Instead of calculating a virtual reference vector in the traditional manner using deadbeat control, the reference vector is innovatively determined through two two-level bang-bang comparators. To improve the performance of the machine, the sampling period is subdivided into two equal time intervals and total 20 synthesized voltage vectors are obtained. Nevertheless, there is no need to evaluate all the 20 vectors by excluding the inappropriate vectors in advance using the reference vector based method, thus reducing the computation time. Moreover, with this proposed method, the complicated calculation of reference vector is avoided. Simulation and experimental results are presented to prove the effectiveness of the proposed method.

Highlights

Finite control set-model predictive control (FCS-MPC) have been increasingly explored for the electric machine drives [1]–[3], power converters [4], [5] in recent years
This paper proposes an indirect reference vector based FCS-MPC method for a three-phase permanent magnet synchronous motor (PMSM) motor
The innovation point is that the reference vector is determined indirectly using the direct torque control (DTC) theory instead of deadbeat control

Summary

INTRODUCTION

Finite control set-model predictive control (FCS-MPC) have been increasingly explored for the electric machine drives [1]–[3], power converters [4], [5] in recent years. Apart from duty ratio regulation, another alternative is to expand the number of the voltage vectors by subdividing the sampling period into several equal time intervals This attempt has been widely investigated in both MPC method [12]–[14] and direct torque control (DTC) method [15], [16]. The multiple vectors based MPC have been introduced in [17], [18], where the deadbeat control based on space vector modulation is employed to obtain the optimal vector and its duty ratio This method can improve the control performance and reduce the computation time by excluding the inappropriate voltage vectors in advance. A common practice to reduce the computation time in MPC is excluding the inappropriate vectors in advance This can be achieved by calculating a reference vector or using the torque or flux constrained look-up table. It can be explained by the fact that the optimal vector minimizes the cost function but the error can be further minimized if there are other candidates

EXISTING REFERENCE VECTOR BASED MPC-FCS METHOD

VIRTUAL REFERENCE VECTOR DETERMINATION

SIMULATION PERFORMANCES

EXPERIMENTAL PERFORMANCES

Findings

CONCLUSION