Wave energy is a renewable energy source with vast potential, which could make significant contribution to world electricity demand in the future. In this paper, a way to electrically interconnect wave energy converters into a farm is described. Measurements of voltage and current wave forms in the interconnection of two PM synchronous machines on the common DC-bus of a marine substation are compared with simulations in MATLAB Simulink. It is demonstrated how the generators intermittently deliver power to the common DC-busbar and how the power, after rectification and filtering of the voltage, is continuously extracted in a resistive load. A unique feature of the variable frequency substation at hand is that it will be located on the seabed.
At the Lysekil Research site, were the marine substation will be installed, the DC-bus voltage will be actively controlled by means of an inverter. This will change the damping and hence the absorption width of the linear generator-based WECs that are connected to the substation. The experiments carried out here demonstrate the principle of operation and verifies that the system works as expected.