Bi-directional sparse parallel partial resonant ac-link inverter

Due to their remarkable merits, partial resonant ac-link inverters have received noticeable attention during the last few years. These bi-directional dc/ac inverters are compact, reliable, efficient, and they offer longer life time compared to the other types of inverters. 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 20 in the original dc-ac inverter to 18 is proposed. The principle of the operation in the proposed inverter, which is named sparse parallel partial resonant ac link inverter, is similar to that of the original inverter. Despite reducing the number of switches, the principle of operation of the proposed inverter is the same as the original inverter. Therefore, partial resonance time during which no power is transferred is still very short. The proposed inverter offers higher reliability compared to the original inverter. Another important feature of this inverter is that it can be fabricated by IGBT modules, which are more compact and cost-effective, compared to the discrete devices. Hence, the proposed converter is expected to be compact, less expensive, and less complicated compared to the conventional partial resonant ac link converters. This paper evaluates the performance of the proposed inverter through both simulation and experiment. The efficiency and reliability of the parallel partial resonant inverter and the sparse parallel partial resonant inverter are also compared in this paper.