A paper by Zeng Ruiyuan, a 2023 Master's student in Electrical Engineering of the Zhejiang University–University of Illinois Urbana-Champaign Institute (ZJUI), along with Tenured Associate Professor Diao Ruisheng, Sun Fangyuan, a 2022 doctoral student in Electrical Engineering of ZJUI, and Dr. Zhou Baorong and Dr. Li Junjie from China Southern Power Grid Electric Power Research Institute, has been published in IEEE Transactions on Sustainable Energy (TSTE), a leading Q1 journal in electrical engineering.

The study, titled Dynamic Evolution and Stability Analysis of GFM-Based Renewable Energy Resources Considering Repeated & Continuous Current Saturation, addresses critical stability challenges in grid-forming renewable energy systems (GFM-RES). As modern power grids increasingly rely on renewable energy and power electronics, issues such as repeated (R-CS) and continuous current saturation (C-CS) can cause severe oscillations, overvoltage, and instability—problems that remain poorly understood.

Using hybrid system theory, the authors derived precise switching conditions for current saturation and proposed a new R&C-CS stability criterion, a desaturation region-based principle, and a novel control strategy (S&D-DC). These methods effectively mitigate saturation issues and cut transient recovery time by 18–32%. High-fidelity simulations confirmed the approach’s effectiveness across various system strengths and fault types.

▲ Hybrid System Theory, Grid-Forming New Energy Grid-Connected System, and Transient Evolution Process

▲ Mechanism Analysis of Repeated & Sustained Current Saturation Under the Coupling of Dynamic Evolution and Control Switching

▲ Design of Preventive Control Strategy for Repeated & Sustained Current Saturation

▲ High-Precision Electromagnetic Transient Simulation Experimental Results

TSTE is an internationally authoritative journal published by the Institute of Electrical and Electronics Engineers (IEEE), with an impact factor of 10.0 and an annual publication output of only 193 papers. Affiliated with the IEEE Power & Energy Society, this journal is dedicated to the research and development of sustainable energy systems and technologies. Its covered research directions include but are not limited to cutting-edge topics such as the modeling, control, and optimization of renewable energy systems (e.g., wind energy, solar energy, biomass energy); power electronic conversion technology; and integration methods of new energy and power grids.