Active Power Decoupling Based on Input Current Ripple Control for Single-Phase Voltage Source Inverter

Abstract:
An inherent low-order ripple power problem caused by the instantaneous ac and dc power imbalance exists in single-phase photovoltaic (PV) inverters. This problem is usually addressed through paralleling large-capacity electrolytic capacitors. In recent years, there have been a lot of studies on using active power decoupling circuits to reduce the capacitance of capacitors, but most of them require complex mathematical derivations to generate accurate decoupling capacitors voltage references or to obtain accurate system predictive models, which are weakly robust to parameter drifting. Therefore, an active power decoupling algorithm based on input current ripple control is proposed in this paper. By the proposed method, the dc and ac power is controlled directly, so that the accurate active power decoupling can be realized with strong robustness in parameter drifting. The effectiveness of the proposed control method is verified by the simulation and experiments based on a hardware-in-the-loop simulation platform and the prototype of a 1kW single-phase voltage source inverter.