A SiC-Based High Power Density Single-Phase Inverter With In-Series and In-Parallel Power Decoupling Method

This paper presents an in-series and in-parallel combination power decoupling method for the single-phase inverter. With basic power equation derivation, the proposed method is analyzed and compared with other methods in theory. The operating principles and the control strategy are introduced. The circuit parameters based on silicon carbide device are designed in detail, and the power losses are evaluated for the circuit. To verify the theoretical analysis, a PLECS simulation model is built. Based on the simulation results, both the proposed method and the in-series method can achieve a more than 89% reduction of the dc-link capacitance compared with the traditional inverter. Furthermore, the proposed method is superior to the in-series method, with a more than 68% reduction of the extra circuit's capacitance. Finally, a 2-kW prototype with a size of 7.25 × 3.6 × 1.4 in
³
and a power density of ~55 W/in
³
is developed. Compared with the in-series method, the extra capacitance can be reduced by about 64% for the proposed power decoupling method. The experimental results are almost consistent with the simulation results. The efficiency for the proposed method is higher than 95%.