Abstract:

The coupled-inductor impedance-source inverter contains multiple inductors and capacitors. The ampere-second and volt-second balance have been commonly adopted for calculating state variables in the stress analysis. But the calculation process is tedious and error-prone. Therefore, to simplify the circuit analysis, a reactive component elimination method is proposed to be applied for coupled-inductor impedance-source inverters. By eliminating the capacitor branches or inductor branches, the circuit can be averaged in one switching period. Then, the voltage and current variables can be calculated in the obtained equivalent average circuits, consequently simplifying the coupling relations among state variables. To illustrate the analysis procedure of the proposed method, current and voltage stresses of a coupled-inductor impedance-source inverter are determined using both the traditional and the proposed methods. Finally, their subsequent comparison and experimental results confirm the effectiveness of the proposed method.

Key words: Coupled-inductor, impedance-source inverter, reactive component, voltage stress, current stress