Coordinated control for grid integration of PV array, battery storage, and supercapacitor

A substantial increase of solar photovoltaic (PV) power generators have taken place in recent years. The intermittent nature of PV energy and quick fluctuations of load demanding require energy storage units (ESU) which generally consists of storage battery and supercapacitor (SC). The development of coordinated control tools for next-generation PV installations, along with ESU, provides flexibility to distribution system operators. The objective of the control of this hybrid PV and energy storage system is to supply the desired active and reactive power to the grid and at the same time to maintain the stability of the dc-link voltage of the PV and energy storage system through coordinated control of power electronic converters. This paper investigates three different coordinated control structures and approaches for grid integration of PV array, battery storage, and SC. A computational experiment system is developed by using SimPowerSystems and Opal-RT real-time simulation technology. The performance of the coordinated control techniques is evaluated.