Demand of electricity is increasing day by day. Power systems are highly non-linear and exhibit low frequency oscillations and so the stability of power systems is one of the most important aspects in power system operation. An electric power system is an interconnection of many large and complicated components where the system oscillates spontaneously for 0.2 to 3.0Hz, at a very low frequencies. In modern power systems for improving small signal stability or to enhance system damping, power system stabilizers (PSS) are widely used. The most practical power system stabilizers involve frequency responses and it provides supplementary feedback stabilizing signals in the excitation system. In this paper, different types of PSS auxiliary controllers like Proportional-plus derivative (PD), Proportional-plus-integral (PI), Proportional-plus-derivative-plus-integral (PID), Parallel PID, Lead Lag controllers and Torsional filter have been designed and parameters are tuned to enhance the steady state stability the SMIB system. Lead Lag controllers which are characterized by its simple implementation are the traditional type of controllers. PID which is a combination of proportional, derivative and integral is the leading type of controllers. It calculates the error between the measured and the desired variables and tries to minimize the error by adjusting the input parameter. Eigen value analysis has also been carried out for two cases without PSS and with PSS.

Full text: IJEIR_1521_Final.pdf