A novel single-phase soft-switching AC chopper without auxiliary switches

A single-phase soft-switched series-resonant ac chopper without auxiliary switches is presented. The presented single-phase ac chopper is configured by a series-resonant conversion without cycloconversion and auxiliary switches. The presented single-phase ac chopper is a series resonator with four main switches to configure adaptively the resonant voltage robes. The output sinusoidal voltage is synthesized by a series of sinusoidal amplitude Quasi-Sinusoidal Pulses (QSPs) following the input voltage amplitude. The presented single-phase ac chopper is operated by frequency modulation with a constant-on time control. Waveform syntheses for the output sinusoidal voltage are clearly derived. A typical design example of a 600 W single-phase soft-switching ac chopper is examined to assess the system performance. The power efficiency is over 92% when the output power is at maximum output rated power. The Total Harmonic Distortion (THD) when the output power is at maximum output rated power is within 5%.