Design and Analysis of a MPC-based Mechanical Hardware-in-the-Loop System for Full-Scale Wind Turbine System Test Benches

Abstract

In this contribution a mechanical-level Hardware-in-the-Loop system based on a Model Predictive Controller, for a 4MW system test bench is proposed. An experimentally validated model of this test bench is introduced and the basis of the mechanical-level Hardware-in-the-Loop system. The main purpose of that system is to emulate the inertia and eigenfrequency of the wind turbine’s drive train at the system test bench, where the rotor is dismounted and hence the eigenfrequencies are altered.The results show that, with realistic motor torque constraints being considered and the original wind turbine controller activated, the proposed concept allows to reproduce the first two eigenfrequencies accurately. Beyond that the transmission behavior from pitch angle to generator speed of the wind turbine at the test bench and of the unmodified, real wind turbine match up to a frequency of 9 Hz in the nominal case. Even with parameter deviations of up to 20% and time-delay of 15 ms the frequency response match up to 7 Hz.