Modelling and Analysis of the Single-Phase Operation of the Belgian PFC Rectifier

Abstract

Boost-type power factor correction (PFC) rectifiers can be used in, for example, battery charging systems for Electric Vehicles (EVs). Conventionally available three-phase PFC rectifiers are limited to output 1/3 of the rated power when connected to a single-phase mains. This work presents the research into the single-phase operation of the Belgian rectifier, a novel boost-type PFC rectifier which allows for full power operation in both single- and three-phase operation (relevant for the three-wire split-phase systems in the USA with a maximum power of 19.2 kW). The single-phase AC-to-DC power converter is operated by paralleling and interleaving the three-phase rectifier bridge legs. By using the analysed triangular current mode (TCM) modulation scheme complete zero-voltage switching is achieved over the entire mains period. The power converter is further analysed with respect to the steady-state operation and component-level modelling. The modelling techniques are used to generate the Pareto-front of efficiency versus power density. The optimal design is selected based on the multi-objective requirements, and is a design with 6x interleaving with a boost inductance of 30µH that results in complete soft-switching transitions and achieves an efficiency of 98.42% with a power density of 5.34kW/dm3. After that, the single-phase Belgian rectifier is compared to the conventional six-switch boost PFC rectifier to identify and quantify the benefits. Finally, a closed-loop control model is proposed and implemented on the 19.2 kW, 1.5kW/dm3 hardware demonstrator for the conversion of a 240 V AC input with a maximum rms current of 80 A into a 380 V DC output to verify the single-phase operation of the Belgian PFC rectifier. Experimental results show efficiencies higher than 98% for power levels larger than 3kW.