This chapter is dedicated to present some control mechanism to cope with the challenges due to the growth of the penetration level of the power electronic interfaced generation (PEIG) in sustainable interconnected energy systems. Specifically, this chapter presents different forms of fast active power injection (FAPI) control schemes for the analysis and development of different mitigation measures to address the frequency stability problem. Among the considered FAPI control schemes are the traditional droop-based scheme, and two propositions implemented in the form of a derivative-based control and a second-order virtual synchronous power (VSP)-based control. All the detailed explanation, DSL-based control is presented for the simulations in DIgSILENT software. Simulation results show that thanks to proposed FAPI controllers, it is possible to increase the maximum share of wind power generation without violating the threshold limits for frequency stability problem in low-inertia systems.