WTG Manufacturer's Experience with Subsystem and Component Validation for Wind Turbines

Conventionally, wind turbine (WT) manufacturers are performing grid compliance tests at the WT level primarily in the field to verify the WT capabilities and performances against certain grid code requirements and validate simulation models accuracy and performance. Such compliance tests are becoming more challenging and numerous due to the growing number of relevant grid code requirements and the rapid growth of WT’s size and rating, which in turn require more powerful test equipment and larger sites to test such turbines. Upcoming standards such as IEC 61400-21-4 and FGW AK KEZ and other industry initiatives aim to address these challenges through the replacement of site-specific tests with tests performed on WT components and subsystems in a controlled test bench environment. This paper presents the experience gathered so far on various test benches including nacelle, electrical generation, converter, and real time digital simulator test benches. The results of these different test benches brought important lessons regarding the transferability of the results through the evaluation and comparison with one another and benchmarking against site specific tests to assess their accuracy in representing the performance, capability, and functionality at WT level. Finally, a long-term grid compliance strategy, revolved around on moving part of the testing campaign to subsystem and component testing and modelling, is presented with a proposal of new test bench and acceptance strategies for the industry.