Model Predictive Current Control of Nine-Phase Open-End Winding PMSMs With an Online Virtual Vector Synthesis Strategy
Authors: Haifeng Wang; Xinzhen Wu; Xiaoqin Zheng; Xibo Yuan
Abstract:
Multiphase permanent magnet synchronous machines (PMSMs) have received widespread attention in large-power high-reliability industrial, aerospace, and military applications. Also, the H-bridge open-end winding (OW) structure can significantly improve the utilization of dc voltage, which is suitable for large-power machine drive, especially for the ship electric propulsion system. In this article, the research is targeted for a high-power PMSM with the application background of ship propulsion, and the specific study is carried out using a downscale 9-kW nine-phase OW-PMSM experimental prototype.
The current error is hard to avoid for finite control set model predictive current control (FCS-MPCC) in multiphase open-end winding permanent magnet synchronous motors. To overcome this problem, an online virtual voltage vector (V3) synthesis strategy is proposed in this article. First, a group of V3 s without harmonic voltage components are designed as the basic vectors for online synthesis. Then, two adjacent basic V3 s and a zero vector are used to synthesize a new V3, which can output arbitrary amplitude and phase angle in the fundamental space. The two basic V3 s are directly selected from the located sector of the predicted reference voltage vector (RVV), and their duration ratio can be simply calculated according to the angle of the RVV in the sector. In this way, the zero error is realized between the new V3 and RVV.
Experimental results have verified the effectiveness and superiority of the proposed strategy, in comparison to existing FCS-MPCC in multiphase OW motor drive systems. Although this article concentrated on the nine-phase OW-PMSM drive, the proposed online synthesis strategy can also be extended to other MPC-based multiphase OW drives.
