Control of AC/DC/AC Converter for Multi MW Wave Dragon Offshore Energy Conversion System

In the paper a direct power and torque control-space vector modulated (DPTC-SVM) algorithm for AC/DC/AC converter is presented. This strategy leads to good dynamic and static behaviors. Additional power feedforward (PF) loop from a generator side converter (GSC) to line side converter (LSC) control improves dynamic of the power flow. As a result, more accurate input-output energy matching allows better stabilization of DC-link voltage. Hence, life time of DC-link capacitors would be prolonged. Moreover, proposed advanced control strategy gives possibility of control in whole power range of active and reactive power injected to the line. Line current has sinusoidal waveform with THD bellow 5% in all operation modes. Presented AC/DC/AC converter with permanent magnet synchronous generator (PMSG) system is considered to be implemented in wave energy converter - Wave Dragon MW [1].