8 papers
Relative-Degree Wall Restricts Passivity-Based Stability Analysis in Inverter-Dominant Grids
Xiaoyu Peng, Zhongze Li, Xi Ru +2
This letter reveals a fundamental limitation of passivity-based distributed stability analysis in power systems. Under the standard formulation, passivity certification inherently…
When Can Phasor-Domain Device Models Be Trusted for Electromechanical Stability Analysis of Grid-Forming Converter-Dominated Microgrids?
Zhongze Li, Xiaoyu Peng, Xi Ru +4
Grid-forming (GFM) converter-dominated microgrids are often analyzed using reduced-order phasor-domain electromechanical GFM models, but the validity of these models is often taken…
Equilibrium-Free Contraction Stability Analysis for Grid-Forming Converter-Based Microgrids
Shijie Peng, Xiuqiang He, Xi Ru +1
Renewable-driven microgrids dominated by grid-forming (GFM) converters are subject to persistent power fluctuations, making equilibrium-known stability assessments restrictive. Thi…
Toward less conservative distributed stability analysis of power systems via matrix-valued differential passivity indices
Xi Ru, Cong Fu, Zhongze Li +2
Passivity indices have been widely adopted to derive distributed stability certificates for power systems. Nevertheless, conventional passivity indices remain scalar-valued even fo…
Matrix-Valued Passivity Indices: Foundations, Properties, and Stability Implications
Xi Ru, Xiaoyu Peng, Xinghua Chen +3
The passivity index, a quantitative measure of a system's passivity deficiency or excess, has been widely used in stability analysis and control. Existing studies mostly rely on sc…
Positive Damping Region: A Graphic Tool for Passivization Analysis with Passivity Index
Xiaoyu Peng, Xi Ru, Zhongze Li +3
This paper presents a geometric framework for analyzing output-feedback and input-feedforward passivization of linear time-invariant systems. We reveal that a system is passivizabl…
Controlled Evolution-Based Day-Ahead Robust Dispatch Considering Frequency Security with Frequency Regulation Loads and Curtailable Loads
Kai Kang, Xiaoyu Peng, Kui Luo +2
With the extensive integration of volatile and uncertain renewable energy, power systems face significant challenges in primary frequency regulation due to instantaneous power fluc…
Compositional and Equilibrium-Free Stability Certification for Power Systems--Part I: Theory
Peng Yang, Xiaoyu Peng, Xi Ru +2
Stability certification for large-scale power systems is challenging due to heterogeneous device dynamics and time-varying operating conditions. This two-part paper develops an equ…