Constant-frequency current slope control for single-phase switch-mode rectifiers without current sensors

Abstract

In this paper, we present a novel control scheme for single-phase boost-type switch-mode rectifiers (SMRs). Based on the input current slopes, which depend on the source voltage, output DC level and boost inductance, the duty ratios of the switches are determined to achieve a unity power factor. No current sensors are required. By utilizing the triangular PWM comparators, the proposed control scheme can be fulfilled with a constant switching frequency. This novel control method with low costs and simple circuitry can be applied to any boost-type SMR. Simulations and experiments are performed. The results show feasibility of the presented scheme.