Mats Leijon

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In this article we present numerical studies of waves interacting with a cylindrical point absorber that is directly driving a seabed based linear generator. For waves useful for power conversion, the wave/point absorber interaction can be modelled , using potential theory assuming an inviscid irrotational incompressible fluid. The generator is modelled as(More)
In this paper, a revitalization of conformal mapping methods applied to fluid flows in two dimensions is proposed. The present work addresses several important issues concerning their application for vortex particle flow solvers. Difficulties of past conformal based method are reviewed. One difficulty concerns the ability of a mapping procedure to represent(More)
Keywords: Stator winding Automated production Industrial robot Electric machine assembly Powerformer Wave energy converter a b s t r a c t Cable wound electric machines are used mainly for high voltage and direct-drive applications. They can be found in areas such as wind power, hydropower, wave power and high-voltage motors. Compared to conventional(More)
This article proposes a simple and reliable damping strategy for wave power farm operation of small-scale point-absorber converters. The strategy is based on passive rectification onto a constant DC-link, making it very suitable for grid integration of the farm. A complete model of the system has been developed in Matlab Simulink, and uses real site data as(More)
In this paper, a generic coordinated control method for wave energy converters is proposed, and the constraints on motion amplitudes and the hydrodynamic interaction between converters are considered. The objective of the control problem is to maximize the energy converted from ocean waves, and this is achieved by coordinating the power takeoff (PTO)(More)
The standard solution for the traction system in battery powered electric vehicles (EVs) is a two-level (2L) inverter feeding a three-phase motor. A simple and effective way to achieve a three-level (3L) inverter in battery-supplied electric vehicles consists of using two standard three-phase 2L inverters with the open-end winding connection of standard(More)
Industrial automation has been recognized as a fundamental key to build and keep manufacturing industries in developed countries. In most automation tasks, knowing the exact position of the objects to handle is essential. This is often done using a positional calibration system, such as a camera-based vision system. In this article, an alternative(More)
The investigation of various aspects of the wave climate at a wave energy test site is essential for the development of reliable and efficient wave energy conversion technology. This paper presents studies of the wave climate based on nine years of wave observations from the 2005–2013 period measured with a wave measurement buoy at the Lysekil wave energy(More)
The stator slot geometry of a cable wound permanent magnet synchronous generator for hydrokinetic energy conversion is evaluated. Practical experience from winding two cable wound generators is used to propose optimized dimensions of different parts in the stator slot geometry. A thorough investigation is performed through simulations of how small(More)