Robust DC-link voltage control scheme for photovoltaic power generation system PCS

A power conversion system (PCS) for photovoltaic power generation system is composed of the DC/DC converter and the DC/AC inverter. To maximize power generation, DC/DC converter operated with MPPT (Maximum Power Point Tracking) algorithm and the PCS has been developed by the method of transformer tab change. DC/AC inverter controls DC-link voltage and grid current. But, single phase grid has 120 Hz (Grid voltage frequency is 60 Hz.) power ripple which arise DC-link voltage ripple. This paper presents a robust DC-link voltage control scheme. The control scheme utilizes a widow averaged DC-link voltage as a feedback signal. Experiment performed with 3 kW PCS and the results support the validity of the control scheme.