Multi-Degree-of-Freedom Load Reproduction by Electrohydraulic Digital-Servo Loading for Wind Turbine Drivetrain

Many drivetrain testing facilities have been built to reproduce multi-degree-of-freedom loads, thus simulating real wind conditions for evaluations of the reliability and durability turbine subsystems. In this paper, electrohydraulic schemes non-torque loading a turbine’s test benches are first analyzed. To deal with control inaccuracy caused by drastically increasing force, along rapid development large-scale turbines, multi-cylinder digital-servo (MEDSL) technology is proposed. A novel cylinders group designed. The proposed MEDSL can provide continuous accurate load recurrence under wider varying operational area group. Moreover, sliding mode controller (SMC) designed realize large dynamic system. By comparing SMC traditional PID in servo-valve controlled cylinder, both simulation experiment results proved advantage SMC. Accordingly, extensive experiments 4-cylinder case were carried out on full-loading bench using SMC-based device. excellent tracking performance complicated signals that represent loads demonstrated feasibility effectiveness method.