Robust Load Frequency Control of multi-area interconnected system including SMES units using Type-2 Fuzzy controller

Abstract

Load Frequency Control (LFC) problem plays an vital role in power systems; its main role is to maintain the system frequency and tie line flow at their scheduled values during normal period in an interconnected system. This paper proposes a new methodology to study the Load Frequency Control (LFC) problem of a three area inter-connected system including Superconducting Magnetic Energy Storage (SMES) units using Type -2 Fuzzy system (T2FS) approach. Here, the technique is applied to control systems include three areas considering Generation Rate constraint (GRC) having two steam turbines and one hydro -turbine tied together through power lines including Superconducting Magnetic Energy Storage (SMES) units. As a consequence of continually load variation, the frequency of the power system changes over time. The salient advantage of this controller is its high insensitivity to large load changes and plant parameter variations even in the presence of non-linearities. The proposed method is tested on a three-area power system to illustrate its robust performance with various area load changes. The results obtained by using Type-2 (T2)Fuzzy controller explicitly show that the performance of the proposed controller is superior to the conventional controller and Fuzzy PI Controller(Type-1 Fuzzy) controller in terms of the overshoot, settling time and robustness. Simulation results confirm the high robustness of the proposed SMES controller with small power capacity against various disturbances and system uncertainties in comparison with SMES in the previous research.