International Journal of Advances in Applied Sciences (IJAAS) Vol. 8, No. 2, June 2019, pp. 117~124 ISSN: 2252-8814, DOI: 10.11591/ijaas.v8.i2.pp117-124  117 Journal homepage: http://iaescore.com/online/index.php/IJAAS Enhanced performance of PID load frequency controller for power systems Dola Gobinda Padhan, Suresh Kumar Tummala EEE Department, Gokaraju Rangaraju Institute of Engineering and Technology, India Article Info ABSTRACT Article history: Received Sep 8, 2018 Revised Mar 27, 2019 Accepted Apr 29, 2019 A novel control structure for designing a PID load frequency controller for power systems is presented. The controller with a single tuning parameter is designed based on a desired closed-loop complementary sensitivity function and Pade approximation. Comparative analysis demonstrates that proposed PID controllers improves the settling time and reduces overshoot effectively against small step load disturbances. Also, the performance and robustness of the controllers have been analyzed and compared. Simulation results show significantly improved performances when compared with recent results. Keywords: Complementary sensitivity Kharitonov’s theorem Load frequency control (LFC) PID Copyright © 2019 Institute of Advanced Engineering and Science. All rights reserved. Corresponding Author: Dola Gobinda Padhan, EEE Department, Gokaraju Rangaraju Institute of Engineering and Technology, Survey No. 288 Nizampet Road, Krishnaja Hills, Bachupally, Kukatpally, Hyderabad, Telangana 500090, India. Email: dg.padhan@griet.ac.in 1. INTRODUCTION Frequency deviation in Power System due to variation between generation and load shall be rectified within a fraction of seconds resulting in stability and security. Load Frequency Control (LFC) of an extensive power framework can be alluded as the issue of controlling the recurrence by directing the created units with reaction to change in stack [1]. For framework soundness, LFC must furnish recurrence with zero enduring state mistakes and tie-line trade varieties, high damping of recurrence motions and diminishing overshoot of the unsettling influence. The objectives specified are conveyed effectively in past works by various creators utilizing Fuzzy rationale PI and PID controllers [2, 3], ideal control [4, 5]. Variable structure control [6, 7], versatile and self-tuning control [8, 9]. Down the line, different tuning rules have picked up the consideration for the previously mentioned goals in which Internal Model Control (IMC) [10] is one among them. The LFC PID controller configuration utilizing Laurent arrangement is clarified by Padhan and Majhi [11]. Double PI controller tuning utilizing swam enhancement calculation is introduced in [12]. The two-degree-of-freedom internal model control scheme suggested by Tan [10] consists of two controllers with two tuning parameters where simultaneous tuning of the two parameters is difficult. In practice, a simple control structure with a fewer number of tuning parameters is desirable. The proposed control structure (see Figure 1) for LFC design consists of only one controller (Gc). Kasireddy et.al designed a PID controller for LFC through reduced model order [13].