75 citations · 246 across the 15 of their papers we have counts for
18 papers
An Energy-Based Framework for Transient Stability of Grid-Forming Converter Networks With Current Limiting
Wei Zhou, Yunjie Gu
Existing analyses for the transient stability of grid-forming (GFM) converters under current limiting mainly address single-converter systems, while network-level transient stabili…
A Small-Gain-Like Framework for Large-Signal Stability Evaluation of Multi-Converter Systems
Qiannan Qu, Kaiwen Chen, Xin Xiang +2
The increasing penetration of grid-connected converters has greatly altered the large-signal behavior of power systems. Their angle dynamics, shaped by diverse control algorithms a…
Consideration of Control-Loop Interaction in Transient Stability of Grid-Following Inverters using Bandwidth Separation Method
Yifan Zhang, Yunjie Gu, Yue Zhu +3
Grid-following inverters have been widely adopted as a grid interface for renewable energy, and ensuring their small-signal and large-signal stability is critical to modern power s…
Large-Signal Stability of Power Systems with Mixtures of GFL, GFM and GSP Inverters
Yifan Zhang, Yaoxin Wang, Yunjie Gu +5
Grid-following (GFL) inverters have very different large-signal stability characteristics to synchronous generators, and convenient concepts such as the equal-area criterion and gl…
Descriptor State Space Modeling of Power Systems
Yitong Li, Timothy C. Green, Yunjie Gu
State space is widely used for modeling power systems and analyzing their dynamics but it is limited to representing causal and proper systems in which the number of zeros does not…
Whole-System First-Swing Stability of Inverter-Based Inertia-Free Power Systems
Yitong Li, Yunjie Gu
The emphasis on inertia for system stability has been a long-held tradition in conventional grids. The fast and flexible controllability of inverters opens up new possibilities. Th…
Impedance-based Root-cause Analysis: Comparative Study of Impedance Models and Calculation of Eigenvalue Sensitivity
Yue Zhu, Yunjie Gu, Yitong Li +1
Impedance models of power systems are useful when state-space models of apparatus such as inverter-based resources (IBRs) have not been made available and instead only black-box im…
Multi-Agent Reinforcement Learning for Active Voltage Control on Power Distribution Networks
Jianhong Wang, Wangkun Xu, Yunjie Gu +2
This paper presents a problem in power networks that creates an exciting and yet challenging real-world scenario for application of multi-agent reinforcement learning (MARL). The e…
Dual Synchronous Generator: Inertial Current Source based Grid-Forming Solution for VSC
Huanhai Xin, Kehao Zhuang, Pengfei Hu +2
In order to improve dynamic characteristics of the power system with high-proportion renewable energy sources (RESs), it is necessary for the voltage source converter (VSC), interf…
Mapping of Dynamics between Mechanical and Electrical Ports in SG-IBR Composite Grids
Yitong Li, Yunjie Gu, Timothy C. Green
Power grids are traditionally dominated by synchronous generators (SGs) but are currently undergoing a major transformation through the increasing integration of inverter-based res…
SHAQ: Incorporating Shapley Value Theory into Multi-Agent Q-Learning
Jianhong Wang, Yuan Zhang, Yunjie Gu +1
Value factorisation is a useful technique for multi-agent reinforcement learning (MARL) in global reward game, however its underlying mechanism is not yet fully understood. This pa…
Revisiting Grid-Forming and Grid-Following Inverters: A Duality Theory
Yitong Li, Yunjie Gu, Timothy C. Green
Power electronic converters for integrating renewable energy resources into power systems can be divided into grid-forming and grid-following inverters. They possess certain simila…
The Intrinsic Communication in Power Systems: A New Perspective to Understand Synchronization Stability
Yitong Li, Timothy C. Green, Yunjie Gu
Synchronization is an essential element in three-phase ac electric power systems. The large-scale integration of converter-interfaced resources leads to the power grid transformati…
Participation Analysis in Impedance Models: The Grey-Box Approach for Power System Stability
Yue Zhu, Yunjie Gu, Yitong Li +1
This paper develops a grey-box approach to small-signal stability analysis of complex power systems that facilitates root-cause tracing without requiring disclosure of the full det…
Modelling Hierarchical Structure between Dialogue Policy and Natural Language Generator with Option Framework for Task-oriented Dialogue System
Jianhong Wang, Yuan Zhang, Tae-Kyun Kim +1
Designing task-oriented dialogue systems is a challenging research topic, since it needs not only to generate utterances fulfilling user requests but also to guarantee the comprehe…
Impedance-Based Whole-System Modeling for a Composite Grid via Frame-Dynamics Embedding
Yunjie Gu, Yitong Li, Yue Zhu +1
The paper establishes a methodology to overcome the difficulty of dynamic frame alignment and system separation in impedance modeling of ac grids, and thereby enables impedance-bas…
Shapley Q-value: A Local Reward Approach to Solve Global Reward Games
Jianhong Wang, Yuan Zhang, Tae-Kyun Kim +1
Cooperative game is a critical research area in the multi-agent reinforcement learning (MARL). Global reward game is a subclass of cooperative games, where all agents aim to maximi…
Interpreting Frame Transformations as Diagonalization of Harmonic Transfer Functions
Yunjie Gu, Yitong Li, Timothy C. Green
Analysis of ac electrical systems can be performed via frame transformations in the time-domain or via harmonic transfer functions (HTFs) in the frequency-domain. The two approache…