Adaptive Current Deviation Control and Improved VDCOL for Enhanced Fault Ride‐Through in CLCC‐HVDC Systems

ABSTRACT The appealing capability of long‐distance and large‐capacity power transmission makes High‐Voltage Direct Current (HVDC) transmission technology become an energy corridor of power systems. The controllable line‐commutated converter (CLCC) is an advanced direct current (DC) conversion device designed to address the commutation failure issues that frequently happen with conventional HVDC. To fully explore the advantages of CLCC and expedite the system's restoration after faults being cleared, an adaptive current deviation control strategy is proposed, and the Voltage Dependent Current Order Limitation (VDCOL) strategy is improved, which are jointly integrated into the constant extinction angle (CEA) control structure. Analysis and validation are conducted using the PSCAD/EMTDC simulation platform. The results demonstrate that the adaptive current deviation control strategy together with the improved VDCOL strategy endows a higher level of active power transmission capability during faults and provides additional reactive power to the alternating current (AC) system, which facilitates the system's restoration.