Comparison of different line start interior permanent magnet synchronous motor types with respect to IE4 efficiency class

Recently, the increasing requirements and tendencies of higher efficiency systems have caused a substantial impact on electric motor design. Designers tend to change their views on motor topologies to provide the predetermined values of higher efficiency classes (such as IE3, IE4, IE5). Line-start interior permanent magnet synchronous motors (LSIPMSM) are strong candidates for higher efficiency class general purpose motors due to their higher MTPA (maximum torque per ampere) values. In this study, three different rotor types of LSIPMSM, i.e. V-magnet type, spoke-magnet type and rectangular-magnet type, are investigated with regard to efficiency requirements of super premium efficiency class (IE4). The impact of designs on rotor cage which is essential for starting and synchronization is also studied. The electromagnetic design study is conducted and then the optimized designs are manufactured and tested. The most applicable motor type is determined by means of its ease-of-manufacture and low cost features.