A Scheme of Power Source Voltage Sensorless Three-Phase PWM AC/DC Converter

Abstract

Many researches on the three-phase PWM ac/dc converter having a unity effective power factor have been presented. This paper presents a scheme of a power source voltage sensorless three-phase PWM ac/dc converter to reduce the size and cost of the system. The effective value and phase angle of the source voltage can be estimated from the current error between the actual and model currents. Furthermore, the feature of this estimation is that the estimation and control characteristics are hardly affected by the parameter variations. The stability of the estimation system and the design of the estimation gains are shown. The initial phase angle estimation scheme is proposed for stable starting of the system. The effectiveness of the proposed estimation algorithm was confirmed by experiments.