Comparative study on conventional controller and PID controller of power system dynamic stability

Abstract

This report presents the comparative study on conventional controller and PID controller in a single machine infinite bus (SMIB). The controller is used to generate the supplementary damping control signals for an excitation system in order to damp out the Low Frequency Oscillations (LFO). The system starts with formulating the mathematical modelling of a single machine infinite bus (SMIB) for simulating the system after experiencing a low frequency oscillation (LFO). The block diagram of the system has been designed in MATLAB software to analyze the performance of a synchronous machine after facing a specific range of disturbance. The conventional controller and PID controller are generated and the simulation is conducted on different value of disturbance to observe the performance of the power system. The disturbance is set by increasing and decreasing the electrical power by 0.1 pu. Output waveform is being analyzed on the overshoot, peak time and settling time. Besides, the eigenvalue and damping ratio are also being analyzed to observe the stability of the system. Based on the analysis result, the PID controller gives a better performance as compared to conventional controller because the output produces lowest overshoot, peak time and settling time. Besides, the PID controller provides negative eigenvalue and highest value of damping ratio.