Design, development and operation of a PHIL environment for Distributed Energy Resources

The challenges in achieving higher integration of Distributed Energy Resources (DER) in electricity grids require advances and novel approaches in simulation and testing. An approach that is increasingly gaining interest is Hardware-in-the-Loop (HIL) simulation and especially Power-Hardware-in-the-Loop (PHIL), where power equipment is connected to a simulated system. This paper firstly discusses interfacing issues of PHIL simulation providing a theoretical basis. A detailed description of the design and development phase of a PHIL environment for DER devices is provided. The development of the Power Interface, stability analysis and design of appropriate protection schemes are presented, aiming at assisting the development of other PHIL environments. As a first experiment, a voltage divider circuit is implemented in the PHIL approach. Subsequently, hardware PV panels and a PV inverter are connected at a simulated simple distribution grid and it is demonstrated that the voltage of the common-node follows the variation of the solar irradiation.