Research On The Semi-physical Experiment System Of The Pelamis-like Wave Energy Converter

The sea is an inexhaustible treasure-house, which contains a wealth of clean, renewable energy. Ocean wave energy generation technology uses various wave energy converters(WEC) to transform unavailable energy contained in the wave into electric energy. Pelamis-Like wave energy converter is one of the most important wave energy converters. It’s of great significance to research and design the semi-physical experiment system of Pelamis-Like wave energy converters for developing this type of WEC.Wave dynamics simulation model of wave energy converter is established with the hydrodynamic software AQWA. A compared simulation is made for linear damping and coulomb damping power-take-off(PTO) system. The result shows that it is necessary to put the real hydraulic energy harvesting system in the simulation model. A simulation platform based on AQWA is established with the real hydraulic PTO system being put in the simulation model with FORTRAN. Simulations are carried out with linear damping, coulomb damping and real hydraulic PTO. The characteristics of motion and energy capture of the WEC are analyzed based on the simulation data.According to the characteristics of motion and energy capture of the WEC, the overall design of the semi-physical experiment system is carried on. Scaling factors are determined according to the characteristics of different buoys. A ISIGHT-AQWA-MATLAB co-simulation optimization model is established, which is used to determine the optimal design parameters of the WEC. Meanwhile, according to the buoy hydrodynamic equations, a dynamic model of the WEC is established in SIMULINK. The comparation of SIMULINK simulation and AQWA simulation verifies the feasibility of the semi-physical experiment system. The mechanical structure is designed and the structural strength is checked.According to the motion characteristics of WEC, the hydraulic driving system is designed. The mathematical model of the hydraulic driving system is established, whose system stability, closed loop stiffness characteristic and accuracy of steady-state are analyzed. The feedforward-PID compound controller is designed based on the characteristic of the ability of load measurement. The time domain simulation model of the experimental system is established, which verifies the feasibility of the semi-physical experiment system.Finally, the of the semi-physical experiment system is constructed. The experimental study on the performance of the hydraulic driving system is carried out, which verifies the tracking capability for a given signal. The experimental studys of WEC whose buoys length are 10 m and 20 m are completed with the semi-physical test-bed. According to the comparation of experimental results and simulation results, it is obvious to know that the semi-physical test-bed has a good performance. What’s more the correctness of the simulation platform is indicated by the test.