Active Power Decoupling on a Differential Single-Phase Inverter With Non-linear Load

This paper presents an experimental analysis of the steady state and dynamic performance of a differential single-phase inverter with active power decoupling under non-linear load. Non-linear loads such as rectifiers pose significant challenges in introducing harmonic distortion to the inverter output current and voltage. When reflected to the inverter's DC-link side, these odd harmonics become even harmonics. This adds to the inherent even harmonics present in the DC-link current, which are due to the output power that oscillates at double the fundamental frequency. The paper begins by analyzing the harmonics introduced by a non-linear load when connected to a differential single-phase inverter. It then examines the effectiveness of active power decoupling in removing these low-frequency harmonic components from the DC-link current. Active power decoupling allows for the effective utilization of the inverter capacitors, enabling highly reliable thin-film capacitors to be used instead of electrolytic capacitors. Furthermore, to demonstrate the effectiveness of the adopted control algorithm, the dynamic and steady-state performance of the inverter was tested experimentally on a 1 kVA non-linear load. The experimental results obtained showed good steady-state and dynamic performance of the inverter with active power decoupling under nonlinear load.