Methodologies for offshore wind power plants stability analysis
Germano R. Mugambi, Nicolae Darii, Hesam Khazraj, Oscar S. Romano, Alin G. Raducu, Ranjan Sharma, Nicolaos A. Cutululis
TL;DR
This paper addresses stability in large, converter-dominated offshore wind power plants with multi-vendor integration. It surveys stability assessment approaches across screening, frequency-domain, eigenvalue, and time-domain methods, highlighting the limitations of traditional SCR in converter-rich networks and endorsing new metrics GSIM and IMR. The authors advocate a hybrid workflow that uses EMT frequency-scanning to derive impedance matrices and supports stability evaluation via impedance-based or eigenvalue analyses, enabling robust handling of offshore cluster interactions. The work underscores the need for standardization, dynamic multi-vendor models, and partially open grey-box representations to accelerate industry adoption and safer deployment of energy hubs. Overall, the study provides a structured comparison and practical guidance for applying stability analyses to multi-vendor OWPPs, aiming to improve reliability and scalability of future offshore grids.
Abstract
The development of larger Offshore Wind Power Plants (OWPPs) is moving towards multi-vendor setups, ultimately aiming to establish Energy hubs. These structures are characterized by installations from different vendors sharing the same connection or closely interconnected points. Control interactions among Wind Turbine (WT) converters and power systems have been detected, and this critical phenomenon can significantly impact the dynamic stability of the system. Various stability analysis methods have been proposed to analyze the interactions between OWPPs at the Point-of-Connection (PoC) and the power system. However, stability studies rarely consider the complex offshore transmission system behind the PoC. Generally, the overall OWPP is blamed for the instability. However, since it is a complex system, it is important to understand which part of the OWPP behind the PoC is causing the problem or is likely to become unstable under certain conditions. Therefore, this paper provides a detailed overview of the advantages and limitations of the current system screening indexes used to design the OWPP, and the stability analysis methods. Each method is discussed, and the appropriate methods, depending on OWPP structure, are evaluated and discussed. The analysis indicates that a combination of time domain and frequency domain methods is necessary for enhancing the definition of stability boundaries.