محمدحسين شريفي پور

A multi-terminal HVDC network is a direct current power transmission system in which more than two terminals are connected to each other. These networks transmit electric power between different regions and enable connection between different power systems. Also, multi-terminal HVDC networks have the possibility of controlling the flow in both directions (from A to B and vice versa), providing high flexibility in energy transmission. HVDC networks are designed to transmit high power, so in the event of an fault, there is a possibility of serious risks for the system components and even the entire power network. For this reason, HVDC network protection is important to prevent equipment damage and increase system safety. Fault localization is a part of protection that increases network stability and reliability. Various methods are used in fault location, and the methods based on transient waves are one of the most widely used and accurate methods. Therefore, in this thesis, two algorithms based on transient waves are presented, which can be used to identify the line where the fault occurred and determine the location of the fault with high accuracy. The first algorithm of fault location is used in the networks formed by the airlines and only the first transient wave is needed in the terminals. In this algorithm, there is no need to calculate the speed of transient waves through frequency, and therefore the volume of calculations has been reduced. Then, the second proposed algorithm, which is developed from the first algorithm, is developed for locating hybrid networks (consisting of overhead lines and cables) and it is necessary to detect the second transient wave in some terminals. In this method, it is necessary to first identify the line where the fault occurred and then determine the exact point of the fault in this line. Next, a three-terminal HVDC network is simulated in PSCAD/EMTDC software and the proposed algorithm is eva‎luated with simulation data in MATLAB software.

سيستم جريان مستقيم ولتاژ بالا چند پايانه , شبكه‌هاي تركيبي , امواج گذرا , مكان‌يابي خطا

multi-terminal high voltage current system , hybrid networks , traveling waves , Fault Location

Mohammad Hossein Sharifipoor

Dr. Sadegh Jamali