Summary
Offshore wind plays a pivotal role in the UK’s net-zero transition and the decarbonisation of power systems. The increasing deployment of high-capacity wind turbine generators (WTGs) and the expansion of larger, higher-voltage (66 kV) offshore array networks introduce new challenges for transient analysis and stability. This paper presents electromagnetic transient simulation results investigating sustained overvoltages in offshore wind farm inter-array cable systems. An asymmetrical fault followed by islanding was studied, revealing significant phaseto-earth overvoltages on healthy phases, reaching up to 3.5 pu and persisting for several cycles.
Read more Read lessThese overvoltages pose risks to critical equipment such as surge arresters (SAs), 66kV cables, transformers and gas-insulated switchgears. Sustained overvoltages were analysed and validated using models of varying complexity and through sensitivity studies. The overvoltage magnitude is mainly driven by the string network and WTG control, whereas its duration is governed by the lack of islanding detection, control mode deadband, and delayed converter blocking. Results confirm that the issue is systemic and control-driven rather than eventspecific, and indicate that sensitivities have limited influence on overvoltage magnitude.
Several mitigation strategies were assessed, with WTG converter blocking and strategic SA deployment identified as the more effective options. The findings highlight the need for improved coordination with manufacturers, robust insulation coordination, and standardised design assessments to ensure system resilience.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | C4_11622_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | United Kingdom |
| Study committees |
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| File size | 1 MB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
LUO Jiajie - Arup Great Britain; HIGGINS Charlotte - Arup Great Britain; KARAMITSOS Spyros - Scottish Power Renewables Great Britain; LIU Gaoyuan - Scottish Power Renewables Great Britain; LOGAN Gary - Scottish Power Renewables Great Britain
Keywords
Offshore wind, sustained overvoltage, insulation coordination, wind farm islanding, overvoltage mitigation
