Abstract

Most of the micro hydro power plants operating in isolated mode are based upon induction generator technology. However; in the recent years, there has been a growing interest in the use of synchronous generator based Micro Hydro Power Plants (MHPPs), for grid connected systems, because of the proven advantages over other renewable technologies where the extension of grid systems are economically viable for grid connection. Among various other components of micro hydro power plants, the speed governor mainly functions to control the hydraulic turbine. It constitutes not only the control mechanism but also the actuating equipment to regulate the flow of water, to start and stop the unit, and to regulate the speed and power output of the generator in case of any electrical disturbance. The proper control of actuating devices for these governors plays a significant role in stable and acceptable operation of the connected power system. The use of the Proportional-Integral-Derivative (PID) based control in speed governors is now gaining popularity because of the simplicity and flexibility. This research work makes an effort to analyze the behavior of the PID vs PI (Proportional-Integral) controllers; for speed governor operation of grid connected MHPP, deploying synchronous generator, under the influence of a electrical disturbance; to identify more suitable controller from the regulation point of view. The dynamic performance of the proposed controllers for speed governor function is fully validated through digital simulations carried out using MATLAB/Simulink software package.