Book excerpt: Protection of Wind Turbine Generators Using Microcontroller-Based Applications focuses on the application of microcontrollers in the protection of wind turbine generators. The book looks at the design and implementation of a versatile digital overcurrent (OC), OV/UV, OF/UF, and negative sequence relays, and addresses the dynamic behaviour of a wind-driven induction generator (IG) connected to a power system grid through a transmission line. The transient responses of protective devices associated with the IG are also studied. Modelling of the digital relay for wind turbine generator protection using MATLAB Simulink consider most of the aerodynamic and mechanical effects that can influence instantaneous output voltage, current, and power. Coverage also includes different AC fault types, a detailed theoretical analysis of fault and protection strategy in AC fault, and the different types of fault detection algorithms to maintain power system reliability.