Morten Kramer

Dr. Morten Kramer

Department of the Built Environment, Aalborg University (AAU), Thomas Mann Vej 23, 9220 Aalborg, Denmark
+1
orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 August 2013 in Energies
Verified
Journal Article
Open access
PDF file
RHRico Hansen
Rico Hansen
Morten KramerMorten Kramer
Morten Kramer
EVEnrique Vidal
Enrique Vidal
The Wavestar Wave Energy Converter (WEC) is a multiple absorber concept, consisting of 20 hemisphere shaped floats attached to a single platform. The heart of the Wavestar WEC is the Power Take-Off (PTO) system, converting the wave induced motion of the floats into a steady power output to the grid. In the present work, a PTO based on a novel discrete displacement fluid power technology is explored for the Wavestar WEC. Absorption of power from the floats is performed by hydraulic cylinders, supplying power to a common fixed pressure system with accumulators for energy smoothing. The stored pressure energy is converted into electricity at a steady pace by hydraulic motors and generators. The storage, thereby, decouples the complicated process of wave power absorption from power generation. The core for enabling this PTO technology is implementing a near loss-free force control of the energy absorbing cylinders. This is achieved by using special multi-chambered cylinders, where the different chambers may be connected to the available system pressures using fast on/off valves. Resultantly, a Discrete Displacement Cylinder (DDC) is created, allowing near loss free discrete force control. This paper presents a complete PTO system for a 20 float Wavestar based on the DDC. The WEC and PTO is rigorously modeled from incident waves to the electric output to the grid. The resulting model of +600 states is simulated in different irregular seas, showing that power conversion efficiencies above 70% from input power to electrical power is achievable for all relevant sea conditions.

1 March 2014 in Ocean Engineering
Verified
Journal Article
Closed access
AZA.S. Zurkinden
A.S. Zurkinden
FFF. Ferri
F. Ferri
SBS. Beatty
S. Beatty
Jens Peter KofoedJens Peter Kofoed
Jens Peter Kofoed
Morten KramerMorten Kramer
Morten Kramer

1 February 2020 in Renewable Energy
Verified
Journal Article
Closed access
CWChristian Windt
Christian Windt
JDJosh Davidson
Josh Davidson
EREdward J. Ransley
Edward J. Ransley
Deborah GreavesDeborah Greaves
Deborah Greaves
MJMorten Jakobsen
Morten Jakobsen
JRJohn V. Ringwood
John V. Ringwood

1 November 2005 in Coastal Engineering
Verified
Journal Article
Closed access
Alberto LambertiAlberto Lamberti
Alberto Lamberti
Renata ArchettiRenata Archetti
Renata Archetti
Morten KramerMorten Kramer
Morten Kramer
DPD. Paphitis
D. Paphitis
CMC. Mosso
C. Mosso
Marcello Di RisioMarcello Di Risio
Marcello Di Risio

1 November 2005 in Coastal Engineering
Verified
Journal Article
Closed access
Morten KramerMorten Kramer
Morten Kramer
Barbara ZanuttighBarbara Zanuttigh
Barbara Zanuttigh
JMJ.W. van der Meer
J.W. van der Meer
CVC. Vidal
C. Vidal
FGF.X. Gironella
F.X. Gironella

1 August 2017 in Renewable Energy
Verified
Journal Article
Closed access
EREdward Ransley
Edward Ransley
DGD.M. Greaves
D.M. Greaves
ARAlison Raby
Alison Raby
DSD. Simmonds
D. Simmonds
MJM.M. Jakobsen
M.M. Jakobsen
Morten KramerMorten Kramer
Morten Kramer