Inverse-saliency PM motor performance under vector control operation

Performance characteristics of an inverse saliency PM machine in which L_d is higher than L_q are investigated for vector control operation. Inverse saliency affects the constant-torque and voltage limit locus lines and the resulting machine operating points. The objective of this paper is to investigate the machine performance and the effects of the machine inverse saliency feature on the current controller design for the major operating modes. An analytical study of inverse saliency PM machines and the design of their control systems is presented. Analytical results are validated using a combination of simulation and experimental results.