Decentralized load frequency control in deregulated environments

Decentralized load frequency control (LFC) problem for multi-area power systems in deregulated environments is studied in this paper. A decentralized PID tuning method is proposed by assuming that the tie-line power flows are disconnected. The general transfer function model of LFC for decentralized control design of deregulated power systems is derived first, and then an IMC-PID method is used to design the local load frequency controllers. A method to analyze the stability of the decentralized LFC for conventional environments is also extended to the deregulated case. The proposed method is tested on a four-area power system under various operating conditions. Simulation results show that the proposed design method is simple to follow, can achieve good performance, and results in implementable PID controllers.

► A method to tune PID-type LFC for multi-area power systems in deregulated environments is proposed. ► A method to analyze the stability of decentralized LFC systems in deregulated environments is derived. ► The proposed method is easy to apply and good damping performance can be achieved.