Single-phase switch mode boost rectifier: an improved design/control applied to three phase AC-DC converters to power up telecommunication system

An improved control technique for raising the efficiency and performance of the single-phase switch mode rectifiers is proposed. The switch mode rectifier operates at unity power factor, exhibits negligible harmonies in input current,. and acceptable ripples in DC bus voltage. The topology of single-phase switch mode rectifier considered in this paper uses a main boost converter and an auxiliary boost converter. The main boost converter is switched at a very high frequency to shape the input current close to the sinusoidal and to eliminate the need of an electromagnetic interference (EMI) filter. On the other hand, auxiliary boost converter operates at a very low switching frequency and works as a current deviator as well as current source for DC bus capacitor of the rectifier. The switched mode rectifier has a very simple and autonomous analog control system for the boost converters. For three-phase applications, a modified topology of single-phase switch mode rectifier is proposed. The modified topology of the rectifier unit and its controller can be considered as a switch mode rectifier (SMR) module. In three phase applications, three identical SMR modules either connected in star or in delta can be used. This paper describes the proposed single-phase configurations of switch mode rectifiers. The steady and dynamic performance of the proposed rectifier is analyzed. Simulated results are given and discussed in detail.