Demand response as a strategy to support grid operation in different time scales

Demand Response has been conventionally used as a resource to support the grid under steady state operating conditions by peak shifting or leveling the electrical load. The characteristics of responsive demand resources can also be used to support the grid during emergency and contingency conditions. Demand resources can respond very fast to provide ancillary services such as frequency regulation and operating reserves for the bulk grid; while the distributed nature of the resource can help in better solving local feeder level problems such as phase balancing, cold load pick up, etc. This paper presents some of these applications of demand response to support the grid under different time scales of operation; ranging from seconds to hours. The analysis will compare before and after benefits from using demand response, a controls strategy for using demand response, and its interface with the legacy grid controls for the above mentioned demand response applications.