Control systems - design and implementation

This chapter discusses the control systems for ocean, wind and wave energy. A general study on wind turbine control suggests that a variable-speed turbine, requiring torque and speed control, can absorb 2.3% more energy than a fixed-speed counterpart, where the speed is fixed by the electrical grid frequency. In the case of wave energy, the numbers are more dramatic. A study on latching control, which is a relatively simple implementation of the more ideal complex-conjugate control, suggests that energy capture can increase by as much as afactor of 2 with control in irregular waves and by up to a factor of 4 in regular waves.