Modeling and Development of a HIL Testbed for DER Dynamics Integration Demonstration

Abstract

The integration of Distributed Energy Resources (DER) into the existing Southern California Edison (SCE) grid has evolved rapidly to accommodate California’s Green House Gas (GHG) reduction goals. The Photovoltaic (PV) systems remain a dominant choice among other DERs and requires an inverter that historically exhibits non-linear characteristics. This criterion underscores the need for a comprehensive PV-inverter model and a sophisticated test bench for demonstrating the operational dynamics and protection functionalities of the system. Given this, a novel impedance-based mathematical modeling is proposed for the PV and inverter. The development of an advanced Hardware-in-the-Loop (HIL) testbed at SCE’s DER Laboratory has described interfaces commercial Rule 21 and IEEE 1547 compliant inverters with the traditional induction and synchronous generator based generations in Real Time Digital Simulator (RTDS) to replicate the simulated model of a medium voltage distribution circuit. Some preliminary simulation and experimentation results yield tremendous agreement and confirm the validity of the modeling approach. The future simulation and demonstration plans are exposed, which show the value of the model and testbed and this contributes evidence to other utilities to further model and develop a testbed for performance evaluations of DER systems.