Price based fuzzy automatic generation control for Indian tariff system

In order to maintain grid discipline and bring about more responsibility and accountability among the participants in the system, the availability based tariff (ABT) mechanism was introduced in Indian power sector. Though there is a considerable improvement, it is further required to maintain the system with greater frequency stability and reduced fuel cost for power generation. This paper presents a new control scheme for price based automatic generation control (AGC) to minimize the unscheduled interchange (UI) charge through nullifying the deviations in frequency and to maintain the generation at various units economically following a disturbance. This scheme also gives the system operator flexibility to schedule the generation in a desired manner. A two input single output Mamdani type fuzzy PID (FPID) controller is used in the proposed scheme to improve the system dynamic response. The proposed scheme is tested on a single area system with four generating units and is compared with an existing control scheme and found effective. The results indicate that the UI charges are considerably minimized by maintaining frequency at normal value and the load perturbations can be adjusted among the generators in a desired manner following a disturbance.