Boost diode rectifier for three-phase variable speed drives supplied from the single-phase mains: Analysis and design

A single-phase diode boost rectifier is proposed in this paper. The core of the proposed rectifier is a multi-switch dc-dc converter with two terminals; an input and an output. The input is parallel-connected with the dc bus capacitor, while the output is connected between the rectifier plus rail and the dc bus plus rail. The converter controls the rectifier current and the dc bus voltage. The rectifier current is controlled constant or pseudo-constant in order to reduce the input current total harmonic distortion (THD). The dc bus voltage is boosted above the mains peak voltage. In contrast to the ordinary single-switch boost rectifiers, the switches of the proposed boost rectifier are rated on a fraction of the dc bus voltage and a fraction of the input current. It makes this topology compact and efficient. Power rating, size and losses depend on the dc bus voltage to rectifier voltage ratio. For example, if the ratio is low, the efficiency is 98 to 99%. The proposed boost rectifier has been analyzed and experimentally verified on a 4 kW prototype variable speed drive. The results are presented and discussed.