The motor loss consists of mechanical loss, copper loss and iron loss. Both the last two consist in stator and rotor and these combinations consist of fundamental, space harmonics and time harmonics components. Space harmonics component is caused by teeth arrangement, primary coil winding and rotor bar arrangement. Time harmonics component is caused by PWM inverter output waveform. Therefore, motor loss components of W , and loss simusoidal W , are shown in Table IV. The motor loss increment by PWM inverter drive is also shown as their deviation. Mechanical loss can be removed in the condition that the rotating velocity of sinusoidal wave source is the same as the one of PWM inverter.