Design of a Large Capacity Line-Start Permanent Magnet Synchronous Motor Equipped With Hybrid Salient Rotor

This article presents a successful design of a three-phase large capacity line-start permanent magnet synchro nous motor (LSPMSM) developed for industrial applications. A hybrid rotor containing both slotted solid steels and cage bars is included in the designed LSPMSM to enhance the motor starting and synchronizing abilities. A salient rotor periphery making air-gap length, which maximizes at the quadrature axis and minimizes at the direct axis, is employed to reduce the harmonics of air-gap flux density and motor losses. The implementation of a genetic algorithm coupled with a neural network optimizes the rotor-periphery saliency ratio and other crucial dimensions for further performance improvement. Finite-element analyses highlight the advantages of the designed LSPMSM by comparing its performance indexes with those of a conventional cage-rotor LSPMSM. The effectiveness of the designed motor is validated by a series of prototype tests.