Effect of Physical Constraints on Load Frequency Control of Deregulated Hybrid Power System Integrated with DFIG Wind Turbine

Abstract -This paper presents a generalized model for load frequency control (LFC) design in a hybrid multi-area deregulated power system including physical constraints. Renewable energy source named doubly fed induction generator (DFIG) based wind energy source is integrated into the system that provides the modified emulating inertial control and reduces the deviations in frequency and tie-line power, following a transient load perturbation. In addition to this, the three basic physical constraints viz. generation rate constraints (GRC), speed governor dead band and communication or time delay have been imposed on the power system that affect the system’s security, reliability and integrity. To get the better performance of the various controllers in power system, their gains are optimized using integral square error (ISE) technique. Present simulation studies reveal that the system’s performance becomes better by the inclusion of DFIG based wind turbine. It is also shown that the dynamic performance of the system becomes poorer by adding physical constraints but it is a more realistic approach. KeywordsAutomatic Generation Control (AGC), LFC, Deregulated system, Bilateral contracts, Disco participation matrix (DPM), DFIG, GRC.