The bang-bang hysteresis current waveshaping control technique used to implement a high power factor power supply

This work reports the operation and development of a high power factor power supply that operates at high switching frequency. An optimum power factor correction is obtained using an ac-dc boost converter associated to a nondissipative snubber as a pre-regulator circuit, which presents reduced commutation losses. The same nondissipative snubber is associated to a Forward converter and then used as a dc-dc stage. The proposed switched mode power supply presents high power factor (0.998), high efficiency (91%), low harmonic content (current and voltage total harmonic distortion rates equal to 2.84% and 2.83%, respectively), and also satisfactory regulation. The converter has been theoretically analyzed, designed, simulated and implemented, where experimental results show that soft commutation in all switches is achieved.