Recent Status: Wave Energy Conversion and Control Systems

With the recent increase in unit cost of energy, secure energy sources related issues and environmental concerns, the renewable energy sources appears to attract more attention to fulfill the ever increasing energy demand of our society. The solar energy and wind energy related research has mostly reached to a certain level of capacity. However, the developments for wave energy related power systems appear to be slower in development relative to the other two environmental friendly energy sources. The irregular characteristic of ocean waves makes the energy extraction a technically challenging task. Adjusting the performance parameters of WEC system and its Power Take-Off (PTO) unit to the right value at right time is the main control approach adopted to increase energy captured. One of the most popular control approach suggested in literature is phase control. The phase control technique is based on adjustment of stiffness and mass properties of the dynamic system. There is also technique called latching control that is another type of phase control technique based on damping property adjustment achieved by applying brake or locking the WEC to meet the resonance condition. In this paper, most of the control strategies to enhance the efficiency were presented. In addition, a new Fuzzy Logic Control based approach is suggested. Keywords: Control, Energy extraction, Renewable energy, Wave energy converter