Graduation Year
2022
Document Type
Dissertation
Degree
Ph.D.
Degree Name
Doctor of Philosophy (Ph.D.)
Degree Granting Department
Electrical Engineering
Major Professor
Lingling Fan, Ph.D.
Committee Member
Chung Seop Jeong, Ph.D.
Committee Member
Kaiqi Xiong, Ph.D.
Committee Member
Qiong Zhang, Ph.D.
Committee Member
Zhixin Miao, Ph.D.
Committee Member
Zhenyu Wang, Ph.D.
Keywords
Renewable Energy Resources, Grid-Following Inverters, Dynamic Modeling, Stability Analysis
Abstract
As the main technology behind renewable energy resources, such as solar PV and wind turbines, inverter-based generation penetration is increasing aggressively. Besides the congestion concerns when interconnecting a large-scale inverter-based resource (IBR) into the power grid, stability issues are commonly existing. The stability events occur more frequently when the resources are in remote area because the transmission line is long and grid strength is weak. One of the most representative and widely observed phenomena of IBR instability is low-frequency oscillation. And this dissertation focuses on investigating the low-frequency oscillations of IBR in weak grids.
The main objectives of the investigation are: 1. capture various types of low-frequency oscillations from unstable IBR behaviors from simulation studies and hardware experiments; 2. conduct stability analysis to identify the root causes of the instability phenomena. For objective 1, test beds are implemented in the electromagnetic-transient (EMT) simulations and in the laboratory with hardware. For objective 2, a series of linear analyses are performed under different IBR operating scenarios.
Moreover, one additional topic is included in this dissertation. Flexible AC transmission (FACT) systems also adopt IBR technology to control the reactive power bank, such as static var compensator (SVC) and static synchronous compensator (STATCOM). Low-frequency oscillations are also observed in the FACT systems. Therefore, the oscillations and stability analysis of SVC are presented as an additional dynamic study example.
Scholar Commons Citation
Wang, Zhengyu, "Dynamic Study of Inverter-based Resources in Weak Grids" (2022). USF Tampa Graduate Theses and Dissertations.
https://digitalcommons.usf.edu/etd/10413
