Keywords: discontinuous conduction mode, DCM, pulse width modulated inverter, PWM, zero current switching, three-phase ZCS, tracking control, sinusoidal output, simulation
A new three-phase ZCS pulse width modulated inverter
A novel three-phase inverter is investigated in this paper. All inverters are, in a sense, a waveform synthesiser where the DC at the input is converted to a desired type of waveform at the output. This paper reports the performance of a tracking controller to synthesise the sinusoidal output. Capacitors are charged/discharged in a controlled manner to track any desired waveform with a finite number of discontinuities. Here, a three-phase sine wave inverter is realised as this is mostly used in industrial drives and power conversion. Extensive simulation is presented to report the performance of the tracking mechanism. The inverter is found to be stable and deliver excellent dynamic performance. Both linear and non-linear types of loads are considered for the study. Operation in the discontinuous conduction mode (DCM) ensures zero current switching (ZCS) at each turn-on of the switching devices. An experimental prototype is fabricated to confirm the usefulness of the proposed PWM technique.