PNNL

Abstract

Microgrids enable the ability to provide uninterrupted power to critical end-use load during severe events, but the proliferation of inverter-connected assets creates significant operational challenges. As the penetration of inverter-connected generation increases, the system inertia decreases and the stability of the microgrid also decreases. Traditionally, the low inertia is addressed by oversizing the rotating machines on the system, typically diesel generators. While the oversizing of units does provide additional inertia, the increased capital and operating costs can become a barrier to deployment. This paper will present a method of using the voltage regulating equipment in a microgrid to generate a synthetic inertia that emulates the inertia associated with synchronized rotating masses. Using this control system, it will be possible to use smaller rotating machines that provide an inertial response of larger units. The control system will reduce the capital and operating costs, while maintain stability, thereby reducing potential barriers to microgrid deployment.