Advanced Assessment of Inverter-based Resources-Storage Technologies on Modern Electric Grids in terms of Power Profiling, Ancillary Services, and Transient Stability
The integration of Inverter-Based Resources (IBRs) with energy storage presents significant challenges to modern power systems, including reduced dispatchability, limited reserve capacity, impaired ancillary service performance, and compromised transient stability. These complexities also hinder the applicability of conventional operational reliability indices. This dissertation addresses these challenges by developing advanced methodologies to enhance grid dispatchability, transient stability, ancillary service provision, and reliability assessment in systems with high penetration of IBRs and storage. Under hybrid power integration, diverse power profiles emerge, such as dispatchable, non-dispatchable, arbitrage, and multi-tier reserve generation, each with unique boundaries and operational roles. To manage these profiles effectively, a linear programming-based optimization framework is proposed to co-optimize unit commitment and reserve scheduling, accounting for the variability and uncertainty of renewable generation. The research further evaluates the co-integration of solar photovoltaic systems with energy storage in electricity markets, emphasizing dispatchability and reserve contributions to minimize operational costs and improve market responsiveness. In parallel, the study explores the impact of renewable integration on transient stability, particularly in low-inertia systems. By examining the transient and sub-transient responses of both conventional synchronous generators and renewable-based units, the dissertation introduces novel stability metrics better suited to capture the dynamic behaviors of evolving grid conditions. These metrics offer enhanced accuracy in reliability assessments and stability planning. Additionally, the work investigates harmonic mitigation and power quality improvements through filter-less multilevel Cascaded H-bridge (CHB) inverters utilizing high-frequency Gallium Nitride (GaN) switches. This approach demonstrates improved power conversion efficiency and reduced total harmonic distortion (THD). To support decentralized operation, a novel autonomous power-sharing method is developed using modified droop control, enabling effective active and reactive power management and ancillary service delivery in both grid-connected and islanded microgrid modes. Collectively, this research advances the integration of renewable energy by proposing robust control strategies, optimization frameworks, and hardware solutions that enhance the reliability, efficiency, and resilience of future power systems. The proposed contributions lay the foundation for more stable, sustainable, and economically viable energy infrastructures.
Ancillary Services, Dispatchability, Electricity Market, Inverter-Based Resources, Reserve, Transient Stability
Networked Digital Library of Theses and Dissertations