Dynamic Enhancement and Protection of Power Systems with Large Penetration of Renewable Energy

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***The need to address global climate change, a worldwide environmental phenomenon that will affect everyone on earth, is the most public driving force for the utilization of renewable energy. Grid integration of large capacity of renewable energy sources and the use of large capacity of electrical energy storage is now a reality. These types of grid require, however, new approaches for system dynamic enhancement and protection. The research work that the applicant is planned to undertake will advance upon two major thrusts.***Thrust 1: Dynamic Enhancement of Power Systems with Large Capacity of Renewable Energies***This thrust will explore the potential use of supplemental controls of Doubly-Fed Induction Generator (DFIG) and Full-Scale Frequency Converter (FFC) wind farms for the mitigation of subsynchronous resonance (SSR: the interaction between series capacitor compensated transmission systems and turbine-generator shaft system) and subsynchronous interaction (SSI: the interaction between series capacitor compensated transmission systems and DFIG-based wind farms).***As most large wind farms employ DFIG and FFC wind turbines, their voltage-sourced converter-based back-to-backs (BtBs) offer decoupled control of the real and reactive power. The use of these control capabilities have been recently proposed for damping power swings, inter-area oscillations and SSI. In integrated power systems incorporating series capacitor compensated transmission lines and high penetration of wind energy conversion systems, SSR and SSI could exist simultaneously during some system contingences. Thus, alleviating SSR and SSI has been an attractive area of research and development targeting at developing practical and effective countermeasures.***Thrust 2: Protection of Power Systems with Large Capacity of Renewable Energies***The results of the investigations on the impact of midpoint STATCOM on the performance of generator phase backup protection and generator loss of excitation protection have revealed that the midpoint STATCOM has an adverse effect on such protections which can be in the form of underreach, overreach or a time delay.***As the Grid-Side Converters of DFIG and FFC wind turbines appear to the generators as STATCOMs, high penetration of these types of renewable energy conversion systems is expected to have an adverse effect on the performance of generator distance relays.***A major investigation in this thrust is exploring the impact of high penetration of wind energy conversion systems on generator distance phase backup protection and loss of excitation protection in order to identify the important issues that protection engineers need to consider when designing and setting the protection system. In addition, practical and feasible solutions to mitigate the adverse impact of renewable energy conversion systems on generator and transmission line distance protection will be explored.**