Control of voltage source converters in wind farm based multi-terminal HVDC transmission systems

This paper describes a control technique for control of voltage source converters (VSCs) in the multi-terminal high voltage direct current (HVDC) transmission systems. The proposed control technique is based on a multi-loop current and voltage control scheme for tracking the reference value of the DC link voltage in the rectifier side to achieve a proper performance during the irregular circumstances of wind farm operation. In addition, the proposed control scheme is able to transmit the maximum power to the consumption sectors. Moreover, the proposed control method on the grid side converter guarantees least amount of current harmonics injection into the AC power grid. The MATLAB simulation results are presented to confirm the effectiveness of the proposed control technique for variation in AC voltage amplitude and frequency of wind turbines output voltage.