Small inverter-interfaced distributed energy resources for reactive power support

The use of small inverter-interfaced distributed energy resources for reactive power support is discussed. While the primary function of these resources is to deliver active power, they can also be used to provide reactive power, often identified as an ancillary service by a utility. Given the large and increasing number of small grid-connected inverters, the total reactive power that can be collectively provided under proper control is substantial. The paper discusses inverter configurations for reactive power production, and presents distributed control strategies that enable these resources to provide reactive power support.