Discrete-Time Current Regulator for Permanent Magnet Synchronous Motor Based on a Unified Complex Vector Model

Under low carrier ratio, the current regulator of the permanent magnet synchronous motor (PMSM) is usually designed directly in the discrete-time domain to avoid significantly reduced control performance. The complex vector principle is widely utilized to simplify the analysis and design of the current control system. However, the principle is difficult to be applied to the interior PMSM (IPMSM) due to its saliency. In order to overcome this barrier, a unified complex vector model is developed, where the reconstructed voltage and current vectors are taken as the state variables. Then, the complex vector model can be directly discretized without any approximations. Based on this model, a discrete-time complex vector current regulator for both surface-mounted PMSM (SPMSM) and IPMSM are proposed. Finally, the experimental verification is carried out on an IPMSM drive test platform. The theoretical analysis and the experimental results indicate that the proposed current regulator has improved control performance and robustness to resistance and inductance parameter mismatch.