Drivetrain Simulation and Load Determination using SIMPACK

Transcription

1 Fakultät Maschinenwesen, Institut für Maschinenelemente und Maschinenkonstruktion, Lehrstuhl Maschinenelemente Drivetrain Simulation and Load Determination using SIMPACK SIMPACK Conference Wind and Drivetrain Prof. Dr.-Ing. Berthold Schlecht Dr.-Ing. Thomas Rosenlöcher Radisson Blu Hotel Hamburg, 7 th of October 2015

2 Technische Universität Dresden Chair of Machine Elements Technische Universität Dresden Chair of Machine Elements Field of research: drive technology, especially gear technology and components

3 Technische Universität Dresden Chair of Machine Elements Dynamic analysis of electro-mechanical drive systems Improvement and verification of simulation techniques Investigations in the time and frequency domain using the MBS and FEM Analyses of drive train systems and drive train concepts Verification of simulation models by measurement results approx. 0.7 MW approx. 1.5 MW approx. 2.0 MW

4 Dynamic analysis of drive systems roller mill train drive ladle cranes wind turbines thruster mechanical watches bucket wheel excavator compressors steam turbines

5 Introduction analysis of wind turbines dimensioning: tower, blades, couplings, shafts, gearings, bearings, generator, dimensioning: drive train components standards (DIN 743, ISO 6336) software (mdesign, KissSoft,..) finiteelementmethod (Nastran, Ansys, )? measurement component load? determination of design loads for single components by transfer/ extrapolation of measured forces and torques multibody-system simulation (MBS) calculation of design loads for single components by recalculation of measured or simulated load cases? simulation component load? determination of design loads for single components by transfer/ extrapolation of simulated forces and torques loads loads global load assumptions (forces/torques at rotor hub, generator) measurement of forces and torques at a wind turbine simulation of wind loads (CFD, Bladed, Flex5, AeroDyn)

6 Dynamic analysis of drive systems Stepped planetary gear (Multibrid) Power splitting gear box (MAAG) Differential gearbox (Bosch Rexroth) 6

7 Dynamic analysis of drive systems Student research project: Design and determination of the dynamic behaviour of a multi-staged helical gearbox for wind turbines

8 Dynamic analysis of drive systems Influences of the gear box support concept: three or four point support Influences of the main frame design on the dynamic behavior of the drive train

9 Dynamic analysis of drive systems Determination of the distribution of the gearing forces Over the width of the gearing Over one revolution of the planet carrier Dependent from modelled rotor loads Weight of the rotor neglected Analysis for nominal load Weight of hub and rotor blades considered Additional modelling of the wind loads force [m] force [m] GET Group 2015 SIMPACK Seminar

10 Design of a 5 MW drivetrain Specification (NREL 5 MW Baseline): Rotor diameter: 126 m Wind speed: 3 m/s to 25 m/s (11.4 m/s) Rotor speed: 12.1 rpm Concept: double-feed asynchronous generator Operational range: 670 rpm to 1167 rpm

11 Design of a 5 MW drivetrain First design of the gear box Scaling of the available 3 MW design without optimisation of ratio split, number of planets, number of stages, consideration of power splitting or differential gearboxes Second design of the gearbox Optimising of design parameters Target: Comparison of gear box designs

12 NREL 5 MW Baseline modelling Implementation of the gearbox in the NREL 5 MW Baseline Modelling all available degrees of freedom for drive train components Supporting of components in gearbox housing by bearings Three-point support of the drive train

13 NREL 5 MW Baseline frequency domain Natural frequencies: 1.01 Hz

14 NREL 5 MW Baseline frequency domain Natural frequencies: 1.13 Hz

15 NREL 5 MW Baseline frequency domain Natural frequencies: 1.72 Hz

16 NREL 5 MW Baseline frequency domain Natural frequencies: Hz

17 NREL 5 MW Baseline frequency domain Natural frequencies: Hz

18 NREL 5 MW Baseline frequency domain Analysis in the frequency domain

19 NREL 5 MW Baseline Analysis in the time domain Simulation of different load cases Example: Wind speed: 12 m/s; 18 m/s; 24 m/s Analysis of the check plots Determination of the loads at the hub Validation of the design of the gear stages

20 NREL 5 MW Baseline further steps Design of an optimised gearbox Load optimised design Mainframe Gearbox Planet carriers Implementation of the mainframe, the gearbox housing and the planet carriers as modal reduced finite element model

21 Flexible gears SIMPACK 9.8 Modelling the gear stages by elastic bodies to analyse: Gear twist under torsional load Effects of body irregularities on the meshing gear contact Effects of body deformation on load distribution and excitation (ring gears, thin gears) Effects of flank modifications and pitch error under load The tooth loads gets distributes by a referenced MPC s the tooth flanks for each tooth

22 Analysis of the pitch drive Simulation model of the pitch drive Combination of the detailed gear box and rotor blade model + = Simulation of the pitching process for different wind conditions, analysis of the bearing and gearing forces Determination of the natural frequencies and comparison with excitations

23 Analysis of the pitch drive ~ 1.3 Hz Bending mode shape of the rotor blade ~ 15.5 Hz Torsional mode shape of the rotor blade

24 Analysis of the pitch drive Simulation model of the azimuth drive Consideration of the motor and the gear box, the nacelle and the tower Simulation of the wind tracking, evaluation of braking concepts, influence of the acting brake torque on the dynamic behaviour Analysis of the mode shapes (superposition: tower, azimuth drive, nacelle)

25 Analysis of the pitch drive ~ 0.4 Hz Bending mode shape of the tower and torsional mode shape of the drive train ~ 15.5 Hz Torsional mode shape of the tower and the drive train

26 Conclusion SIMPACK enables a detailed analyses of wind turbines to determine critical operational states and component loads for the design, certification and optimisation

27 Thank You for Your Attention Technische Universität Dresden Department of Mechanical Engineering Institute of Machine Elements and Machine Design Chair of Machine Elements Münchner Platz 3 D Dresden