Performance Response Improvement of Automatic Voltage Regulator Using Linear Quadratic Gaussian Tuned Controller
C. N. Muoghalu#, I. U. Uju#, C. B. Mbachu#,
#Department of Electrical and Electronic Engineering, Chukwuemeka Odumegwu Ojukwu University, Uli, Nigeria
Abstract— This paper has presented performance response improvement of Automatic Voltage Regulator (AVR) using Linear Quadratic Gaussian Tuned Controller (LQGTC). The controller was designed using the Control and Estimation Tools Manager (CETM) LQG controller design method of the automatic tuning of the MATLAB/Simulink. The developed simulation model was completely designed as a single input single output (SISO) system for the two possible scenario of operation of an AVR closed loop system. The simulation results indicated that the introduction of the LQGTC was able to improve the time domain performance parameters for transient as well as steady state response, and generally reduced deviation error with effective tracking of desired terminal voltage. For the first case scenario called AVR_sys1, the improvements achieved with the LQGTC were: rise time by 20%, the time to peak overshoot by 21%, percentage overshoot by 86%, and settling time by 60%. The second case scenario called AVR_sys2 showed improvement in rise time by 26%, time to peak overshoot by 30%, percentage overshoot by 51%, and settling time by 62%. In order to validate the effectiveness of the LQGTC, different desired terminal voltage values were considered and the results obtained were the same as those from unit step input, which validated the capability of the proposed controller to provide improved, robust and effective contol for an AVR system.
Keywords-: AVR system, LQGTC, SISO, Terminal voltage
I. INTRODUCTION
Steady and reliable voltage supply is essential for efficient working of electrical equipment. This is can be achieved using Automatic Voltage Regulators (AVRs). Thus a constant voltage level is sustained by AVR to electrical equipment loads that need a steady and reliable voltage supply. The application of AVR in electrical power systems ensures that the terminal voltage of a synchronous generator is kept at a constant level. This is achieved by using the AVR to control the exciter voltage of the synchronous generator.