Improving security for wind energy systems in smart grid applications using digital protection technique

Abstract

Wind power generation is the clean energy source by which the pollution in the environment can be reduced to an extent and also it can be installed in and around the cities for electrical supply. The wind energy generated at the level of distributed generation also reduces the impact on the transmission system in terms of loss in the line and improves the efficiency of the power system. The increase in the level of penetration of wind power generation into an island power system network, causing severe threat in the system in terms of protection and security. The decrease in system inertia by means of increasing in Renewable Energy Sources (RES) causes an impact on the stability of the system and further may lead to a blackout of the system. The protection and control of this system are becoming more complicated due to the penetration of RES into the system. So in order to solve these issues, an intelligent control technique is implemented between the robust energy storage system and wind energy system. The Load Frequency Control (LFC) is required to emulate the virtual inertia into the island power system to stabilize the frequency variations and power variations. Furthermore, a digital frequency relay is implemented to protect the system from large power fluctuations for longer duration and a security system is implemented for protecting the whole island system from cyber-attacks. To verify the effectiveness of controller as well as protection system robustness, it is tested for different load disturbances and by increasing the penetration level of wind power, the digital relay has been tested for large frequency variation in the system by using MATLAB/Simulink.