Valuing of inertia and fast-acting storage devices in interconnected power grids

Inertia;Fast-acting storage

Xu, Ti

关键词: Inertia;    Fast-acting storage;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/99176/XU-DISSERTATION-2017.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

As power systems evolve, integration of renewable energy, lightweight-turbine generators and other electronic devices result in: 1) less inertia and maybe worse primary frequency responses (from transient stability perspective of view); 2) stricter ramping requirement (from system operation perspective of view). Fast-acting storage devices can provide both energy and ancillary services through some specific control algorithms. Such energy and ancillary service designs for non-conventional units require test systems that represent the characteristic complexity and features of actual power systems. To provide insightful, realistic simulation results, a systematic method based on statistics summarized from actual system models and publicly available data is developed to create synthetic networks that behave similarly to actual models. Addition of cost and dynamic models into synthetic network base models is essential for energy economic and transient stability studies. The synthetic power system models are then used to study how inertia reduction impacts the system primary frequency response and oscillation behavior. Both time-domain simulation and modal analysis technique are adopted to study resource inertia's impacts on power system dynamic responses. In particular, we investigate the locational dependence of inertia's impacts on the system. Given the location-dependent influences of reduced inertia, we propose an algorithm to control fast-acting storage devices for provision of virtual inertia services. In addition to a commonly used metric - frequency - power system dynamic performance is evaluated in terms of the rate of change of frequency, as well. We verify the effectiveness of the proposed control algorithm for enhancement of power system transient stability using a small-scale test system and a large-scale synthetic network model. Comparison of the proposed control algorithm with other storage control methods is also addressed in this document.Furthermore, we develop two different formulations to model unit commitment problems, in consideration of frequency stability constraints. One formulation simplifies the system full dynamic model for integration into a regular unit commitment simulation framework, while another constructs a sensitivity-based model to estimate system frequency responses. Those two simulation frameworks are applied to determine the economic value of virtual inertia services and fast-acting storage devices to the system. We also compare those two formulations through illustrative simulation studies. Those results validate the proposed methods and contribute towards the development of smarter algorithms on other non-conventional units for enhancing power system stability and reliability.