A proposal for improving efficiency of inverter driven electrical motors

Conventional inverter output has PWM output. This pulsed output waveform reduces insulation life time, contributes to quick degradation of the bearings and also is often source of acoustic noise. Furthermore, losses of PWM inverter-driven motors increase. In this paper a novel topology is proposed which is capable of generating a sinusoidal waveform, with low harmonic distortion. If the proposed method is used for driving motors, motor efficiency increases due to reduced losses and lifetime of the motor may be extended. The paper describes the topology used for generating power-level sinus output and how it works. The proposed converter is implemented and tested with resistive and inductive loads. The converter is shown to have the desired properties and the efficiency is shown to be above 95%. The tests on the converter while switching the load on and off illustrate that the converter output voltage is not affected at all from load switching.