Decentralized Biased Controllers for Load - Frequency Control of Interconnected Power Systems Considering Governor Dead Band Non-Linearity

A new approach for the design of decentralized biased controllers for load-frequency control of interconnected power systems is presented in this paper. In the design of load-frequency control system, it is a usual practice to use simple proportional plus integral (PI) controllers to reduce the area control error (ACE) of the system to zero in order to obtain satisfactory system performances. Generally, the PI controllers are designed based on either Integral Squared Error (ISE) criterion or Maximum Stability Margin (MSM) criterion. In this paper the optimum proportional plus integral biased controllers are designed based on the compromise between the ISE criterion as well as MSM criterion to obtain better transient and steady state responses. These biased controllers are designed and implemented in a two — area interconnected thermal power system with non-reheat turbines considering governor deadband (GDB) non-linearity. Based on the simulation results it is proved that the biased controllers provide better transient as well as steady state response and increased stability margin when compared with the responses obtained using conventional (PI) controllers designed using ISE criterion.