This stage I project has evaluated the gains in terms of efficiency, flexibility and robustness of an electromechanical PTO system which transforms the bi-directional movement into a uni-directional rotation that can easily be fed to a generator.
As a possible solution for the high installed power and low conversion efficiency problems of wave energy the project team (Engie Fabricom - Ghent University) looked at a smart planetary gearbox solution (PST – Power Split Transmission).
A planetary gearbox with 3 axes (1 input, 2 output) will be used to convert the variable power from the WEC prime mover . This power flow is divided over 2 optimally controlled output axis. One axis - coupled to the main generator - is controlled to move with constant, unidirectional speed. Control is exerted through the second axis using a customised algorithm controlled auxiliary machine.
The PTO system is under patent application, and includes at its core the intelligent use of a power sharing Transmission as outlined above.