All the generators being developed by the group require the use of some form of power conditioning before the power can be fed into a local grid, either as part of the national system or as a local, stand-alone system. The power electronics and its control is therefore of fundamental importance both to the quality of the electricity supply and the control of the energy converter itself. Converter systems are being investigated depending on the energy system involved and the design of generator employed. In the case of a direct drive wave energy generator, electrical energy is produced as a variable frequency, variable amplitude sine wave varying from second to second. The power electronic interface and its control in this case utilises a 4-quadrant converter incorporating a DC link capacitor operating at high voltage, as shown adjacent. Power electronics are being developed and studied for wind wave and tidal stream systems as well as for more conventional systems such as variable speed diesel systems.
Key contact: Li Ran