Comparison of HVDC and HVAC transmission systems

Power transmission mainly depends on the Alternating Current in various fields of life. Especially (AC) is commonly used in the short and medium distances, but that the process of power transfer may face several problems when it's affirmative for power transmission to the distal distances. So these problems and obstacles necessitate to search new ideas and find alternative solutions. Because the truth is that relying on the system stream of (AC) accompanies many problems for the power transmission and also difficult to control, as well as increasing the cost transmission system. In this study, we have put forth advantages and disadvantages of them by making comparison of HVDC and HVAC transmission systems. Power losses have been calculated in both systems by considering different transmission line distances. In addition, the voltage variation between both sending and receiving sides has been found for each of two systems considering different transmission line distances. All tests that have been performed for putting forth disadvantage and advantage of the high voltage transmission systems have been done by the systems working under normal and abnormal situations. As a result of studies, HVAC transmission systems in short and medium distances, HVDC have been proven to be advantageous in case of long distances. Key words: HVAC power transmission system, HVDC power transmission system.