This book presents innovative techniques and approaches to maintaining dynamic security of modern power systems that have a high penetration of renewable energy sources (RESs). The authors propose a number of frequency control strategies and schemes to address and evade stability problems in system frequency and voltage that can lead to power interruption and power failure/blackout. The book includes case studies aimed at validating the effectiveness of the techniques and strategies presented, and will be a valuable resource for researchers working in electrical power engineering, power system stability, dynamics and control, and microgrids.