ABSTRACT
This chapter presents a decentralized load-frequency control (LFC) design for a multi-area power system. It considers the design of proportional integral derivative (PID) LFC controllers in the presence of constant time delay. The LFC objectives in a multi-area power system are to keep, simultaneously, the frequency deviation of each area at the nominal values and the tie-line power changes at the scheduled levels. To achieve these objectives, the area control error (ACE) is used as a feedback signal. Decentralized multivariable controllers are often preferred over fully cross-coupled multivariable controllers since the former have simpler structure and include less number of tuning parameters. The load frequency control scheme requires transmission of the measured ACE signals from remote terminal units (RTUs) to the control center and transmission of control signals from the control center to the generating units. In conventional LFC, signals are transmitted via dedicated communication channels, which is the responsibility of the large utilities.
