Discrete Displacement Hydraulic Power Take-Off System for the Wavestar Wave Energy Converter
| Autor: | Rico Hjerm Hansen, Enrique Vidal, Morten Kramer |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Engineering
Control and Optimization Wave energy hydraulics PTO Hydraulics Energy Engineering and Power Technology Mechanical engineering lcsh:Technology wave energy Wavestar WEC jel:Q40 jel:Q jel:Q43 jel:Q42 jel:Q41 jel:Q48 jel:Q47 Hydraulic accumulator Electrical and Electronic Engineering Hydraulic machinery Engineering (miscellaneous) Wave power jel:Q49 Hydraulic motor lcsh:T Renewable Energy Sustainability and the Environment business.industry Electrical engineering jel:Q0 jel:Q4 Power (physics) Hydraulic cylinder Electricity generation Electric power business Energy (miscellaneous) |
| Zdroj: | Energies; Volume 6; Issue 8; Pages: 4001-4044 Hansen, R H, Kramer, M & Vidal, E 2013, ' Discrete Displacement Hydraulic Power Take-Off System for the Wavestar Wave Energy Converter ', Energies, vol. 6, no. 8, pp. 4001-4044 . https://doi.org/10.3390/en6084001 Energies, Vol 6, Iss 8, Pp 4001-4044 (2013) |
| DOI: | 10.3390/en6084001 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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