A Realistic Approach Towards Solution of Load Frequency Control Problem in Interconnected Power Systems

This paper attempts to identify the different issues related to frequency oscillations in power systems and offers newer and reliable approach to mitigate them. Load frequency control (LFC) is important to identify the error pertaining to tie-line power exchange in multi-area power systems. A practical system calls for a robust LFC system to handle variations of different parameters owing to load variations. Classical LFC models available in the literature approaches this LFC problem based only on turbine inputs and swing equation and does not consider other important parameters such as stator currents, field voltages, damper winding voltages and network equations etc., which renders the existing models impractical. This paper introduces detailed model using equation based LFC that considers the above parameters and has been implemented on both single and multi-area power systems for validation. For multi-area interconnected power system network, LFC is introduced considering area interchange control (AIC) concept. Integral (I), Integral derivative (ID) and proportional integral derivative (PID), controllers are used to mitigate the frequency oscillations as well as tie-line power deviation between different areas. Three different meta-heuristic algorithms, namely: Salp swarm algorithms (SSA), Grasshopper optimization algorithm (GOA), Collective decision optimization algorithm (CDO) have been employed to tune the controller parameters and their results have been compared. To make the analysis much more relevant to practical systems, different load perturbations are also considered i.e. low, medium, and heavy load perturbation. Results obtained demonstrate the efficiency of the proposed approach with SSA giving the best tuned parameters for the controllers studied.