Permanent magnet synchronous motor for general purpose energy efficient drive

The permanent magnet synchronous motor (PMSM) has the potential for energy saving in general applications such as fan, pump and compressor drives. New rotor geometry is suggested for this machine which eliminates the drawbacks of the conventionally used circumferentially or radially magnetized rotor geometry. In this paper the performance of this machine with the proposed rotor geometry is compared with the conventional geometries for the same magnet volume and conductor density, employing field based circuit analysis. The performance of the machine for different operating conditions is also investigated. The asynchronous performance is studied using a pseudo constant speed model. Effects of variation of design parameters, on asynchronous performance are indicated. The machine design is modified making it suitable for inverter driven applications