Model Predictive Current Control of Nine-Phase Open-End Winding PMSMs With an Online Virtual Vector Synthesis Strategy

The current error is hard to avoid for finite control set model predictive current control (FCS-MPCC) in nine-phase open-end winding permanent magnet synchronous motors. To overcome this problem, an online virtual voltage vector (V-3) synthesis strategy is proposed in this article. First, a group of V-3 s without harmonic voltage components are designed as the basic vectors for online synthesis. Then, two adjacent basic V-3 s and a zero vector are used to synthesize a new V-3, which can output arbitrary amplitude and phase angle in the fundamental space. The two basic V-3 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 V-3 and RVV. Moreover, an online pulse generation algorithm corresponding to the new V-3 is proposed, which can calculate the symmetrical pulse sequences in real-time for the multiphase OW drive system without the space vector modulator. Finally, experimental results have verified the effectiveness and superiority of the proposed strategy, in comparison to existing FCS-MPCC in multiphase OW motor drive systems.