A low-cost distributed control strategy for rooftop PV with utility benefits

Increasing adoption of rooftop photovoltaic (PV) generators presents a growing challenge to some distribution utility companies, as legacy local controls were never intended for high penetration rates. Some countries have already begun the process of updating their control standards for grid-tied PV systems. This paper presents a low-cost distributed control strategy for grid-tied, rooftop PV generators that addresses some of the concerns of high penetration PV while also adding some benefits to the utility. The control strategy does not require an advanced communications infrastructure but still allows for some aggregate control of the active and reactive power outputs of the PV units and their grid-tied inverters. The paper demonstrates that a distribution company that employs this control strategy to address the issues of high penetration PV will also be able to gain improved power factor correction and potentially new ways to gain revenue from open market interactions. Simulations of the control strategy during daily load and insolation cycles are presented based on the IEEE benchmark 13-bus feeder system.