This paper deals with the implementation of a Fast Active Power Injection (FAPI) controller in a Type-4 Wind Turbine. Two different FAPI controllers, droop-based and a modified derivative-based controller are proposed and investigated under real-time simulation platform. The implementation is done in a Real-Time Digital Simulator (RTDS) by using the functionalities of RSCAD software. The IEEE 9 bus system is taken as a case study to quantitatively check the suitability of the implemented controller. The response of the wind turbine observed in EMT simulations is compared against the response obtained via numerical simulations with a generic wind turbine model built-in DIg SILENT PowerFactory software. The details of the model implemented in RSCAD provides better insight on capturing the impacts of controller parameters. Obtained results clearly demonstrate how the proposed controller can effectively improve the dynamic frequency performance of the power system.