Development of a fuzzy logic controller for boost rectifier with active power factor correction

This paper presents the use of fuzzy logic to derive a practical control scheme for boost rectifier with active power factor correction. The methodology integrates fuzzy logic control technique in the feedback path and linear programming rule on controlling the duty cycle of the switch for shaping the input current waveform. The proposed approach avoids complexities associated with nonlinear mathematical modeling of switching converters. The control action is primarily derived from a set of linguistic rule written in accordance to experience and intuitive reasoning. Instead of generating fast pulse-width-modulated (PWM) signal, the digital signal processor is required to generate a slow-varying dc signal only for determining the PWM ramp function. Moreover, the number of sensing element is lesser than the classical rectifier as it is unnecessary to sense the supply voltage for shaping the input current. Computer simulations of the closed-loop performance in respect of load regulation and line regulation are presented and favorably compared to the ones obtained by the average current mode controller using small-signal modeling design technique.