Helsen J.,Catholic University of Leuven |
Vanhollebeke F.,Hansen Transmissions International |
De Coninck F.,Catholic University of Leuven |
Vandepitte D.,Catholic University of Leuven |
Desmet W.,Catholic University of Leuven
Guaranteeing reliable and cost-effective wind turbine drive trains requires expert insights in dynamics during operation. A combination of advanced modeling techniques and detailed measurements are suggested to realize this goal. The flexible multibody modeling technique enables the simulation of dynamic loads on all drive train components. Moreover it facilitates estimation of structural component deformation caused by dynamic loading. This paper gives a detailed overview of the assumptions made in this modeling approach. Furthermore the influence of the different structural component flexibilities is investigated in detail. To gain confidence in the models created, model validation by means of a comparison with measurements is necessary. To overcome issues concerning test repeatability experienced in field testing, test-rig testing is suggested as a valid alternative. In order to be representative, dedicated dynamic load cases, which represent specific dynamic behavior of the gearbox in a wind turbine need to be realized on the test-rig. However a highly dynamic test-rig complying with the specifications was not commercially available. Therefore Hansen developed a high dynamic test-rig with a nominal power of 13.2 MW and a peak power capacity of 16.8 MW. A back-to-back gearbox configuration was used. The complexity of controlling dynamics of the test-rig was solved by identifying dedicated load cases which represent specific wind turbine behavior. This paper describes the development process of the project consisting of four phases. During two phases a scaled set-up was used, which enabled iterative optimization of the complex interaction between the mechanical dynamics and the electrical controller of the test-rig. In the final part of the paper the two previously discussed approaches are combined, as it discusses results from the validation of simulation models using measurements performed on the 13.2 MW test-rig. © 2010 Elsevier Ltd. All rights reserved. Source
Hansen Transmissions International | Date: 2010-06-24
A planetary gear transmission unit includes a planet carrier which supports and locates circumferentially spaced pairs of planet gears, and at least one planet shaft. The planetary gear transmission unit further includes a planet shaft locking mechanism between the at least one planet shaft and the planet carrier for preventing the at least one planet shaft from rotating around its own axis, the planet shaft locking mechanism being provided between an axial end face of the planet shaft and the planet carrier in a direction substantially parallel to the planet shaft. An advantage of the planetary gear transmission unit is that rotation of the planet shaft relative to its axis in the planet carrier is prevented. The unit results in a free of wear contact between planet shaft and planet carrier, thereby allowing all degrees of freedom of the planet shaft without disturbing the load distribution between the planet gears of a pair on one planet shaft.
Hansen Transmissions International | Date: 2010-08-03
Hansen Transmissions International | Date: 2010-11-29
A planetary gear unit includes a planet carrier having a backplate and being provided with planet shafts distributed uniformly around the planet carriers axis and extending through bores in the backplate, each planet shaft rotatably supporting a pair of planet gears by planet bearings, the planet gears being mounted between a ring gear and a sun gear for mutual interaction. The planetary gear unit further includes a key provided in a keyway of the planet shaft and extending to the backplate for preventing the at least one planet shaft from rotating around its own axis. The key and keyway are provided at a location positioned between 45 and 270 in a clockwise direction around the circumference of the planet shaft, with 0 being defined as a point at the planet shaft circumference corresponding with the largest distance from the centre of the bogie plate seen from the rotor side onwards.
Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: ENERGY-2007-2.3-03 | Award Amount: 2.68M | Year: 2008
One of the major causes of failures of mechanical systems (e.g. drive trains, pitch systems, and yaw systems) in wind turbines is insufficient knowledge of the loads acting on these components. The objective of this pre-normative project is to set up a methodology that enables better specification of design loads for the mechanical components. The design loads will be specified at the interconnection points where the component can be isolated from the entire wind turbine structure (for gearboxes for instance the interconnection points are the shafts and the attachments to the nacelle frame). The focus will be on developing guidelines for measuring load spectra at the interconnection points during prototype measurements and to compare them with the initial design loads. Ultimately, the new procedures for the mechanical components will be brought at the same high level as the state-of-the-art procedures for designing and testing rotor blades and towers which are critical to safety. A well balanced consortium, consisting of a turbine manufacturer, component manufacturer, certification institute, and R&D institutes will describe the current practice for designing and developing mechanical components. Based on this starting point, the project team will draft improved procedures for determining loads at the interconnection points. The draft procedures will be applied to three case studies with each a different focus, viz. determining loads at the drive train, pitch system, and yaw system; the latter one taking into account complex terrain. The procedures will be assessed by the project team and depending on the outcome the procedures will be updated accordingly and disseminated. All partners will incorporate the new procedures in their daily practices for designing turbines and components, certifying them, and carrying out prototype measurements. Project results will be submitted to relevant standardisation committees.