Automatic generation control of a hydro-thermal system in deregulated environment

This paper deals with application of automatic generation control (AGC) to deregulated power system and makes a maiden attempt to provide a new practical AGC model to cater to the needs of a modern restructured hydro-thermal power system. Several DISCO Participation Matrix (DPM) and Area Participation Factor (APF) have been tried out and dynamic responses for frequency, tie flow and generations are obtained to examine the performance of the system in deregulated environment considering integral controllers. Investigation has been carried out to study the effect of generation rate constraint and the importance of APF in deregulated environment. Studies also reveal that the conventional integral controllers are quite robust and the optimum integral gains once set for nominal condition need not be changed for plusmn25% variations in system parameters and plusmn20% variations in operating load condition from their nominal values. The sensitivity of the optimal controller gains to DPM and APF has also been brought out. For the first time, studies have been carried out for the selection of suitable values for governor speed regulation parameter R for the hydro and thermal plants in the deregulated mode. System studies reveal the satisfactory operation of the hydro-thermal system conforming to the requirements in the deregulated environment