Active Power Control of Grid Integrated Multiple Rooftop PV Plant with Power Quality Enhancement

Abstract

This paper presents an active power scheme for a microgrid consisting of multiple two-stage rooftop photovoltaic (PV) systems. Each PV panel is of different power ratings. This rooftop PV microgrid is able to operate either in an islanded mode (IAM) or the grid connected mode (GCM). A control strategy for a two-stage PV-inverter (PVI), i.e., the grid forming inverter (GFI), utilizes voltage control to regulate the point of common coupling (PCC) voltage and accord the load demand in IAM. Moreover, the control scheme improves the power quality (PQ) of the rooftop microgrid by offering reactive power compensation to local loads and offers the unity power factor (UPF) operation at the PCC (Point of Common coupling). The system controller contains the DC-DC converter controller that achieves automatic transition between full PV power mode and limited PV power mode. This transition helps to control the functioning of PV-inverter in an islanded mode if the PV array power is larger than the load demands.