Combined Cycle Unit Controllers Modification for Improved Primary Frequency Regulation

During the past few decades the combined cycle unit dynamics and its associated controllers have become an important research subject. It has now become necessary to understand the operation and existing control strategies for such combined cycle units; this of course is if we are to undertake a comprehensive evaluation of their performance under system disturbance status. This paper focuses on the frequency regulation performance. Its main contention is that an improvement of the control strategies will 1) ensure a better dynamic response to typical system contingencies, 2) deliver a better primary frequency regulation, and 3) maintain the internal machine variables within safe operational levels. The proposed control strategies were applied over the IEEE 14-bus system and our readings showed that modifications of the control strategies do influence better primary frequency regulation responses of the combined cycle unit within limits of a safe operation of the electric system and unit alike.