Comparative Analysis of using Single / Three-Phase Voltage-Source for SVPWM Three-Phase Inverter Feeding a PM Servo Motor

In this paper, a comparative analysis of using single-phase or three-phase voltage-sources for Space-Vector pulse-width modulation (SVPWM) three-phase inverter feeding a Permanent-Magnet (PM) servomotor is presented. In industrial applications, the three-phase voltage-source is commonly used and available. However, in sometimes the availability of three-phase voltage-source is not easy, permissions and facilities from service provider are required. These costs much money to make the three-phase voltage-source available. In small power applications, the single-phase voltage-source is sufficient to provide the required power and the three-phase voltage-source is not needed. The study compares the two cases from point of view of total harmonic contents of voltages and currents of the PM servomotor in each case. The results show that in case of using single-phase voltage-source, the total harmonic distortion of phase and line voltages is reduced by 42.689 %. The total harmonic distortion of load current is reduced by 45.32 % at half load and by 40.44 % at full load. Consequently, there is an improvement in the quality of the PM servomotor voltages and currents. The size of the harmonic filter is reduced and the drive system harmonic effect on the grid due to grid connection is reduced significantly.