Validation of an electric motor and a variable frequency drive system for yaw position control in offshore wind turbines

Abstract

With the increasing demand for clean and renewable energy sources, the need for reliable offshore wind technologies is undeniable. Given the elevated costs of maintenance at sea, it is crucial to ensure the proper functioning of each of the components of the machine, therefore, proper validation is essential. This thesis presents a methodological approach on the validation of one of the actuators from the yaw system, responsible of keeping the turbine facing the wind at all times. Each actuator is comprised of an electric motor and a variable frequency drive (VFD), which have been tested in a back-to-back test bench, property of GE VERNOVA. First, two small motors have been evaluated to obtain their internal parameters and familiarise with the tools and procedures. Then, two 7.5 kW motors have been studied to ensure that they are capable for implementation in the wind turbine, and they have been compared to find the better candidate. The results have shown that the Bonfiglioli BE160M seems to present better features that the Nord 160M/6CUS in terms of torque capabilities, efficiency, and size. Nevertheless, more testing is desired to corroborate the results. In conclusion, opting for the Bonfiglioli motor could potentially improve the performance of the GE VERNOVA offshore turbines. As future work, it would be interesting to support the findings by simulating real wind loads on the back-to-back test bench and analysing thermal properties of each motor.