Dynamic Response of a Single-Rotor Wind Turbine with Planetary Speed Increaser and Counter-Rotating Electric Generator in Starting Transient State

The paper presents a theoretical study on the dynamic behavior of a novel single-rotor system with planetary speed increaser and counter-rotating direct current (DC) generator, patented by authors, during transient stage from rest. The analytical dynamic model of the mechanical subsystem is based on the decomposition of the wind system into the component rigid bodies, followed by the description of their dynamic equations by using the Newton-Euler method. To these dynamic equations are added the linear mechanical characteristics of the DC generator and the wind rotor. The system of equations allows establishing the analytical equation of motion of the wind system and implicitly the time variation of the mechanical power parameters. Numerical simulations of the obtained analytical dynamic model were performed in MATLAB-Simulink in start-up mode from rest for the case study of a 100 kW wind turbine. These results allowed highlighting the time variation of the kinematic parameters (angular velocities and accelerations), torques and powers for all system shafts, both in transient regime and steady-state. The implementation in this case of the counter-rotating generator indicates a 6.4% contribution of the mobile stator to the generator total power. The analytical and numerical results obtained are useful to researchers, designers and developers of wind turbines aiming to optimize their construction and functionality through virtual prototyping.