Automatic generation control before and after deregulation

This paper addresses and discusses how AGC is formulated before and after deregulation. AGC is among a set of services called ancillary services defined by the Federal Energy Regulatory Commission (FERC). To allow open transmission access and encourage a competitive wholesale electric power market, deregulation was introduced by FERC in 1995 in its Notice of Proposed Rulemaking (NOPR). Before deregulation ancillary services, including AGC, were provided by a single utility company called a control area that owns both transmission and generation systems. This type of utility is known as a Vertically Integrated Utility (VIU). Since the inception of deregulation the concept of VIU is no longer applicable and the power system structure has changed and allowed specialized companies for generation (GenCos), transmission (TransCos), distribution (DisCos), and Independent Contract Administrators (ICA) to emerge. The paper focuses on the formulation and operation of AGC to accommodate this new environment. It also addresses provision of other ancillary services in the deregulated framework.