Bi-directional partial resonant converters with reduced number of switches

Abstract

Due to their remarkable merits, partial resonant ac link converters (PR-acL) have received noticeable attention during the last few years. These converters are compact, reliable, efficient and they offer longer life time compared to the other types of converters. However, they require more switches which make the control process more complicated. In this paper, a modified configuration that reduces the number of switches from 24 in the original ac-ac converter to 20 is proposed. The principle of operation in the proposed converter which is named sparse parallel partial resonant ac link converter (SPR-acL), is similar to that of the original converter. Despite reducing the number of switches, the partial resonant time during which no power is transferred is still very short. The proposed converter offers higher reliability compared to the original converter due to a reduction in the switch count. Another important feature of this converter is that it can be fabricated by IGBT modules, which are more compact and more cost-effective compared to the discrete devices. Hence, the proposed converter is expected to be more compact, less expensive, and less complicated compared to the conventional partial resonant ac link converters. This paper evaluates the performance of the proposed converter. The efficiency and reliability of the parallel partial resonant converter and the sparse parallel partial resonant converter is also be compared in this paper.