Implementing a Behind-the-Meter Commercial and Industrial Microgrid: Key lessons in grounding, protection, and control

Abstract

With the promise of reduced carbon emissions, scalable and modular design, and improved reliability, microgrids are deemed essential components of grid modernization and are gaining a lot of attention from utilities and end customers. Particularly, businesses and corporations, also referred to as commercial and industrial (C&I) customers, are deploying microgrids to increase resilience against potential outages and reduce their energy costs. In addition, with the advancement of generation technologies, inverters are becoming increasingly popular, leading to the advent of inverter-based microgrid systems. However, similar to other emerging technologies, the integration of microgrids presents new challenges to the conventional operation of power systems. In the context of microgrid protection, especially in islanded operation, effective grounding, the insulation coordination of primary equipment, and the behavior of inverters during short circuit faults introduce challenges to conventional system protection schemes. In addition, the operation of customer resources should be properly controlled to avoid any adverse impact on the utility grid.