Optimization of the energy harvesting cycle and converter design for a wave energy converter with Electro Active Polymers

This research focusses on the conversion process from mechanical wave energy to electrical energy using an innovative approach with Dielectric Electro Active Polymers (DEAP). These materials have shown great potential as deformable electromechanical actuator devices, however, the generator mode is unexplored yet. Such a deformable DEAP structure could offer distinctive advantages in wave energy applications, where present non-deformable structures typically suffer from the marine conditions and the complex coupling between the irregular slow motion of the waves and electrical generators. The overall material properties, conversion fundamentals of the DEAP in generator mode, optimal energy harvesting cycle and power electronic design of the Power Take Off system (PTO) are investigated. It is shown that the energy harvesting is maximized using the constant field strategy with an optimized charge and discharge current amplitude, allowing efficient conversion even with poor electrical material properties and small deformation ratios. In addition, the desired high efficiency PTO design is challenged by the given high voltage and low current operation conditions. A Zero Voltage Switching – Clamped Voltage (ZVS-CV) converter is designed and tested for this application.