Evolving the electric utility distribution substation into a microgrid

Abstract

There is a lot of conversation about microgrids and how they are the future. This seems to be a truth based upon the ever-increasing deployment of DER worldwide. And when the microgrids are described they are typically shown as a self-healing network with a topography that creates a loop of some kind. This might be a great design for new feeder installations, but it would probably mean a lot of additional construction for the existing infrastructure of substations and feeders. In this paper, we review the concept of a microgrid and examine how the existing operational feeders should be completed based upon actual load measurement data. This includes an investigation on how photovoltaic-specific resources would support the feeder for eventual transformation of the feeder into a sustainable microgrid. The simulations show how appropriate deployment of distributed energy resources (DER) will actually harden feeders and substations. However, it should be noticed that the current DER policies of many US States reduce the microgrid potentials to become fully exploited. The result of this paper offers additional directions how to deploy DER on existing infrastructure in a thoughtful and practical manner.