Development and implementation of a new single phase soft switching power factor correction circuit

Nowadays, power electronics systems and equipments are more crowdedly used. These systems use harmonic currents and require from AC line and so AC line current and voltage waveforms are distorted and overload the system by decreasing the power factor (PF) ratings. Harmonics affect badly other participants from the same AC line. Because of these facts, day by day harmonic standards are developing by legislations.Power factor rating is related with the multiplication of displacement factor and AC line current harmonic ratio. Displacement factor is the cosines of phase angle between AC line voltages and current, for the resistive load it will take the value of ?1?. For Power Factor Correction (PFC), AC line current harmonic content have to be decreased. For this reason, single phase AC-DC ZVT-ZCT PWM converter designed with diode bridge and boost converter which is controlled for maximum load current in every condition by requiring less harmonic sinusoidal current from the AC line.The proposed converter works with soft switching. Main switch turns on with ZVT, turns off with ZCT and there is no extra current or voltage spike. Auxiliary switch operates both ZVT and ZCT times. Auxiliary switch turns on with ZCS and turns off with ZCS without voltage stress however there is also current stress comes from the resonant current but it is diverted to the output side by coupling inductance. So, auxiliary switch current stress is lowered by diverting this resonant current to the load. With this topology total efficiency can reach 98% from 300 W and 100 kHz switching frequency with 0.99 power factor in sinusoidal current shape.Key Words: Boost converter, harmonic, power factor, soft switching, ZCS, ZCT, ZVT.