Load Controller Design for Wind Turbine HIL Testbench
The cost of wind energy must be reduced to meet the growing demand for cheap green electricity. Therefore the uptime on wind turbines must be increased to ensure high availability and stable supply. Hydraulic pitch systems are the biggest contributor to wind turbine faults however these faults may not always be critical for sustaining operation. The HyRel project at AAU is concerned with developing fault tolerant control onto a pitch system of a hardware-in-the-loop test bench to allow operation under specific faults. To emulate practical operation a load system has been implemented into the test bench. This project aimed to develop and implement a load force controller that should be robust toward parameter variations and disturbances from the pitch system. To do so a model of the hydraulic and mechanical system was constructed and verified. The Separate-Meter-In, Separate-Meter-Out configuration of the load emulation system enables control of flow and/or pressure separately for the load cylinder chambers. This yields various control options and therefore this project aimed to suggest the most suitable control strategy for practical operation of the test bench.