Load Frequency Control for multiarea Power System using Secondary Controllers

Abstract

Load frequency control (LFC) is essential for the stable operation of a power system network. The principal task of LFC is to manage the output of the generator with respect to change in the network frequency and tie-line power; such as to restore the scheduled frequency and power exchange with other areas in a prescribe bounds. This paper carries out an analysis of the LFC for 2 areas reheat thermal system and 4 areas thermal reheat system using a generation rate constraint (GRC), by comparison of performances of secondary controllers like model predictive control (MPC), proportional integral derivative (PID), and Fuzzy cascaded PID as load frequency control scheme. A well-known optimization algorithm, i.e., Big Bang Big Crunch (BBBC) is used to obtain optimal gains of PID controllers. Various load perturbations in different areas have been considered to check the response of the controllers.  Comparative analysis of the results has been obtained in terms of overshoot, undershoot and settling time. It is seen that in all cases, apart from some peaky oscillation in responses, MPC performs better than other controllers, specifically in terms of settling time. The robustness of the MPC controller is also more evident than the other controllers. HIGHLIGHTS Two area and 4 area thermal power systems have been taken for the case study PID, Fuzzy cascaded PID and MPC control schemes have been designed for the LFC A simulation model of the 2 and 4 areas power systems is presented and used to design control schemes The performance and effectiveness of all control approaches have been examined under different disturbance scenarios GRAPHICAL ABSTRACT