Multi-Virtual-Vector Model Predictive Current Control for Dual Three-Phase PMSM

Tianjiao Luan,Yang Long,Qi Li,Zhen Zhang,Zhihao Zhu,Zhichao Wang,Chunhua Liu

doi:10.3390/en14217292

Abstract

This paper proposes a multi-virtual-vector model predictive control (MPC) for a dual three-phase permanent magnet synchronous machine (DTP-PMSM), which aims to regulate the currents in both fundamental and harmonic subspace. Apart from the fundamental α-β subspace, the harmonic subspace termed x-y is decoupled in multiphase PMSM according to vector space decomposition (VSD). Hence, the regulation of x-y currents is of paramount importance to improve control performance. In order to take into account both fundamental and harmonic subspaces, this paper presents a multi-virtual-vector model predictive control (MVV-MPC) scheme to significantly improve the steady performance without affecting the dynamic response. In this way, virtual vectors are pre-synthesized to eliminate the components in the x-y subspace and then a vector with adjustable phase and amplitude is composed of two effective virtual vectors and a zero vector. As a result, an enhanced current tracking ability is acquired due to the expanded output range of the voltage vector. Lastly, both simulation and experimental results are given to confirm the feasibility of the proposed MVV-MPC for DTP-PMSM.

Highlights

Due to the advantages of high efficiency, high power density, and high reliability, permanent magnet synchronous machines (PMSM) have attracted more and more attention in electrical drives, such as electric ship propulsions, electric vehicles, electric aircraft, etc. [1,2,3]
Finite control set model predictive control (FCS-MPC) is more widely used in PMSM drives because it can be fully combined with the discrete switching characteristics of inverters and the nonlinearity of the motor system can be considered in the cost function [8]
It is worth noting that a relatively high current ripple occurs in finite control set model predictive control (FCS-MPC) because only one voltage vector is acted in the whole control period

Summary

Introduction

Due to the advantages of high efficiency, high power density, and high reliability, permanent magnet synchronous machines (PMSM) have attracted more and more attention in electrical drives, such as electric ship propulsions, electric vehicles, electric aircraft, etc. [1,2,3]. In order to improve the steady-state performance of traditional FCS-MPC, some strategies to increase the numbers of voltage vectors have been proposed. The scheme of the virtual vector lacks the regulation of currents in fundamental subspace, which leads to the degradation of steady-state performance. How to how to regulate the currents in both fundamental and harmonic subspaces is the key to further improving the steady-state performance of MPC for multiphase electric drive systems. This paper proposes a multi-virtual-vector MPC (MVV-MPC) scheme which effectively suppresses the components in the x-y subspace and provides a more accurate current tracking in α-β subspace. The o1-o2 subspace 3reopf 1-7 resents the zero-sequence harmonic components in the order of 3k (k = 1,3,5...), which are ignored due to the isolation of the neutral point.

Virtual Voltage Vector

MPC Based on Virtual Vectors

Proposed MVV-MPC Scheme

The Calculation of Virtual Vector Duration Time

The Strategy Analysis of MVV-MPC

Simulated Results