High efficiency PWM techniques for digital control of DC-AC converters

The paper deals with advanced sinusoidal pulse width modulation (PWM) techniques for digital control of voltage-source three-phase inverters. A key factor for inverter performance optimization, as regards output spectral quality, power conversion efficiency and switching losses, is the combined exploitation of different techniques, the most suitable for any operating condition being automatically selected by the control system depending on the application requirements. Particularly remarkable in this context is the role played by a novel PWM technique, purposely conceived with the aim of drastically reducing inverter switching losses. A multiprocessor architecture has been devised for the control system, which handles both the high-level control tasks and the on-line synthesis process of the inverter gating waveforms without the need for specialized hardware. Extensive simulation studies as well as preliminary experimental tests in the application domain of AC motor drives and uninterruptible power supply systems have emphasized the validity and wide applicability of the digital techniques used for inverter control