Three-phase voltage-fed inverter with new conceptual optimum PWM strategy for high-power applications

This paper presents a new approach to select the low frequency switching optimum PWM patterns in a voltage-source-fed PWM inverter for large capacity utility interactive power conditioner which is to be specified under a condition of minimized THD of output-side line voltage in order to suppress higher harmonic voltage and current components. A feasible test is implemented for utility-power source by using a trially-produced three-phase optimized PWM inverter with low-pass filter using IGBTs which is designed for high power application. It is verified that a low frequency switching optimized PWM pattern are effective to minimize higher harmonic voltage components in terms of a compact low-pass filter. Furthermore, this experimental work provides high efficient and high-power quality DC/AC converter characteristics. And it is proved that this optimum PWM pattern under a condition of a low frequency switching scheme has an excellent voltage and current waveform performances as compared the voltage-fed inverters operating at various types of PWM patterns.