Speaker: Nicholas David, ECpE Graduate Student
Advisors: Jim McCalley and Zhaoyu Wang
Title: Improving the Role of DFIG Wind Turbine Inertia in Power System Frequency Response
Abstract: Inertia impacts power system frequency response and is a critical factor in enabling the very high penetration of renewable energy sources. The use of power electronic converters is decreasing the amount of physical inertia coupled to the system and DFIG wind turbines may become its only source. The impact that DFIG wind turbines have on requency response is unclear. Additionally, because their controls are not designed for use in low-inertia power systems, their physical inertia is not well-utilized. The impact that both physical and control dynamics have on characteristics of the frequency response are studied using transfer function methods and a degrading effect is found from conventional controls. The role of DFIG physical inertia is improved using a novel controller that is designed to add a level of transient-only frequency response that otherwise does not exist. The proposed controller is designed in a straight-forward way and allows one to design and prescribe the fast frequency response. Experiments of grid-connected and islanding operation prove that sufficient capability exists for DFIG wind turbines to provide inertia for regulating frequency. This work can improve the reliability and utility of DFIG wind turbines.