One of the most challenges in the development of smart grids today is the presence of phasor measurement units with modern communication facilities. The presence of such technologies will enable advanced smart grid applications that were not possible before such as the real time tracking of system dynamics. In addition, one of its goal issues is to maintain a high level of system stability. However, with rapid expansion of power system to meet the needs of the increasing demands of customers, and under the pressure of economical aspects placed by utilities to push the systems to operate very close to their limits, system wide disturbance become more likely. Therefore, the need for a systematic study and design of a comprehensive system control strategy is gaining more and more attention. Wide area protection is a concept of using system- wide information and sending selected local information to remote locations in order to mitigate the propagation of major disturbances. This book proposed a WAMPAC system with a defensive approach to counteract the transient instabilities in power systems. The system objective is to maximize the system stability and avoid occurrence of blackouts.