Digital Loss-Free Resistor for power factor correction applications

The synthesis of a Digital Loss-Free Resistor (DLFR) based on a boost converter in Pulse-Width-Modulation (PWM) operation is presented. The proposed control law is obtained by applying discrete-time sliding mode control theory on the discrete-time model of the boost converter to control the input current. The control law calculates the duration of the switch on-time at the beginning of each switching period in order to reach the proposed discrete-time sliding surface. The resulting digital Loss-Free Resistor (DLFR) can be used as a preregulator for power factor correction in one-phase circuits. Simulations are in good agreement with theoretical predictions.