Optimal Rotor Shape Design of LSPM With Efficiency and Power Factor Improvement Using Response Surface Methodology

Recently, the line-start permanent magnet motor (LSPM) has been a well-known motor due to its technical advantages in academic and industrial applications. The LSPM combines a permanent magnet (PM) rotor that allows higher motor efficiency during the synchronous operation and an induction motor squirrel cage rotor for starting the motor by connecting it directly to an ac source. In this paper, we will deal with the efficiency and the power factor (PF) improvement of a 3.7 kW, two-pole, three-phase LSPM. The efficiency improvement can be effectively achieved by designing the optimization of the rotor structure using the response surface methodology. The optimized slot shape of PM was selected for the prototype machine, which improves the efficiency and the PF of the LSPM.