Fault analysis of uncontrolled rectifier HVDC links for the connection of off-shore wind farms

The present paper introduces the use of an uncontrolled rectifier HVDC link for the connection of off-shore wind farms. The use of an uncontrolled rectifier instead of a line commutated thyristor (LCT) rectifier represents clear advantages in terms of installation cost and operation reliability. However, the rectifier can no longer be used to limit the HVDC link current during on-shore grid faults. The present paper introduces a method to control the HVDC link voltage and current by modifying the off-shore ac grid voltage, which, in turn, is controlled by the wind turbines. Simulation results show good performance in steady state and during on-shore ac grid f aults.