Design of a sinewave inverter for alternative energy

The authors describes the principle and design criteria adopted for a small economical, portable, robust inverter used for outdoor or remote area power supply (RAPS). Sine-weighted pulse-width-modulation (PWM) techniques applied to a push-pull inverter with a front-end filter are used. The front-end filter, using a cross-coupled choke on the low 12 V side, makes it a current fed inverter and hence suitable for starting motors. The topology offers a sinusoidal flux in the main step-up transformer, and thus a good efficiency at low loads. The cost is similar to that of push-pull center tap quasi-square inverters