Optimal placement of the run capacitor in single-phase induction motor designs

A summary is presented of some of the investigations published in an Electric Power Research Institute (EPRI) report (EL-4152-CCM, 1987) concerning the optimization of single-phase induction motors with respect to efficiency for given performance constraints and costs. In this study advanced optimization techniques yield relations between efficiency, cost and capacitance value of the run capacitor. The concept of the optimal capacitance of the run capacitor is formulated to provide a basis for understanding the retrofit configuration for single-phase induction motors proposed by C.L. Wanlass (1977). Theoretical, computational and experimental investigations of the Wanlass configuration are presented to show that this retrofit can significantly improve the efficiency of single-phase induction motors