This thesis deals with the new approach for harvesting renewable energy from sea waves. The main research problem is finding a way to efficiently extract the energy of the sea waves with the S3 concept using power electronics converter. The required operational high voltage of the generator limits the choice of possible power electronic converter topologies that can be employed, while a wide converter’s power range is imposed with the pulsed character. A large amount of energy is circulating in the system, consequently, power electronics conversion losses are making a substantial impact on the produced power. Therefore, the efficiency of the power converter has to be optimized over the whole operating area to reduce overall losses...