Modular Performance Testing and Comparative Evaluation Method for Wind Turbine Retrofit Schemes

To overcome the limitations of existing evaluation methods and performance testing for wind power generation systems, this study proposes a modular framework for performance testing and comparative assessment. Methodologically, the approach establishes a baseline configuration for simulation and provides optional interfaces for experimental, hardware-in-the-loop, or bench testing under identical boundary conditions. By employing a unified metric system, the proposed method enables a comprehensive evaluation of annual energy production (AEP) gains, power curve deviations, damage equivalent loads (DEL) when cycle-resolved load histories are available, fatigue- and peak load proxy variations, efficiency fluctuations, temperature rise margins, and reliability proxy indicators. A demonstrative case study is conducted using illustrative numerical data parameterized for a generic 2.5 MW-class doubly fed wind turbine to compare three retrofit schemes: blade replacement, gearbox optimization (S2), and a pitch system upgrade. When annual energy production (AEP) is utilized as the sole metric, the blade replacement scheme yields a 3.32% increase. However, it concurrently increases the fatigue load and peak load proxies by 6.11% and 3.72%, respectively. Conversely, a comprehensive assessment incorporating load, temperature rise, vibration, and reliability identifies the gearbox optimization (S2 scheme) as the highest-ranked option under the current weighting configuration, with a reproducible overall score of 0.65. The weight sensitivity analysis further shows that the preferred scheme can change when engineering priorities change. Ultimately, this work demonstrates the proposed method’s capability to highlight the discrepancy between single-metric and holistic performance optimization, providing standardized support for scheme selection, project acceptance, and the evaluation of wind turbine retrofit schemes.