Inverter Model and Control Strategies for Single-Phase Rooftop Photovoltaic in Unbalance Three–Phase Residential Network

Abstract

The installation of single-phase rooftop photovoltaic (PV) are growing world widely, which have several benefits and drawbacks in residential low voltage (LV) distribution system. In one hand, this distributed generation (DG) is easy to install, has low maintenance costs, and subsidies in price. On the other hand, as PVs are installed, without controlling their ratings and locations it may deteriorate the overall grid performance including reversed power flows, high losses and unacceptable voltage profiles. This paper proposes modelling and controlling strategies for grid-tied, rooftop PV inverters that address some concerns of high penetration PV while also adding several benefits to the utility. The modelling strategy contains of a proper inverters’ control, which is developed in order to extract the maximum amount of the photovoltaic generator. The control strategy does not require an advanced communications infrastructure, however it allows for several collective controls of active and reactive power outputs of the PV units and their grid-tied inverters. The proposed strategies are simulated in Matlab/ Simulink platform. The results show that the inverters are devouring very less voltage and current harmonic and able to maintain approximately constant voltage profile for highly unbalanced system.