Load Frequency Control for a Distributed Grid System Involving Wind and Hydro Power Generation

The use of renewable energy resources in the power system has been increased in the recent years. But the power production by these resources can’t be controlled like in thermal plants. As a result, the standalone operation of renewable energy is not reliable. Hence, grid connection of these along with conventional plants is preferred due to improved performance in response to dynamic load. It is observed that fluctuations in frequency, caused due to load variations, are high with increase in penetration of renewable resources. In order to suppress frequency deviations owing to load and generating power fluctuations caused by penetration of renewable resources, there are many load frequency control (LFC) methods. They include Flat Frequency Control (FFC), Tie-line Bias Control (TBC), and Flat Tie-line Control (FTC). The frequency and tie-line flow are controlled by tie-line bias control (TBC). In this work, a PID control technique is adopted to control frequency and tie-line power bias in a power system network involving wind, hydro and thermal plants