Comparing the reliability level of high-capacity transmission systems: HVDC-VSC, HVDC-LCC and EHVAC

Implementation of high-capacity power transmission systems in power systems is a growing trend. Among these systems, HVDC and EHVAC power transmission systems are the most popular because of their capabilities and their low investment costs over the long distances. Despite of the mentioned advantages, the reliability of the high-capacity power transmission has been a major concern for power system operators. In terms of reliability, the occurrence of an error in a high-capacity power transmission system (such as HVDCs) causes a large loss of capacity in the transmission network, which can have a major effect on the performance of this system. Therefore, reliability assessment of high-capacity power transmission systems is necessary. In this paper, the reliability level of three modern technologies (HVDC-VSC, HVDC-LCC and EHVAC in different structures) is compared. By comparing these systems, the most proper system for high-capacity power transmission from the reliability viewpoint can be selected.