Over Voltage Fault due to Disconnection of Consumer’s Transformer Neutral Wire  

作　　者：Erdene Adiyasuren Enkh-Od Erdene Sergelen Byambaa Shagdarsuren Gantumur 

机构地区：[1]Mongolian University of Science and Technology,Ulaanbaatar 14191,Mongolia

出　　处：《Journal of Energy and Power Engineering》2023年第1期11-14,共4页能源与动力工程（美国大卫英文）

摘　　要：Practically,the load currents in three phases are asymmetric in the power system.It means that the impedances are different in all three phases.If the consumer’s transformer neutral cut off and/or was disconnected from the neutral of power supply source,then there will be some trouble and failure occurred.The current in the neutral wire drops down to zero when the neutral wire is cut off and the phase currents of all three-phase equal to each other since there was no return wire.The currents are equal but the voltages at the phase consumers are different.Especially for residential single-phase consumers,the voltage at the consumers of the phase varies differently for three phase systems when the neutral wire was disconnected at consumer side and even the voltage at the consumers one or two of those three phases becomes over nominal voltage or reaches nearly line voltage.In this case,the electronic appliances in that phase will be fed by high voltage than the rated value and they can be broken down.In the power system of UB(Ulaanbaatar)city,there are some occasional such kind of failures every year.Obviously,many electronic appliances were broken down due to high voltage and the electricity utility companies respond for service charge of damaged parts.

关 键 词：Neutral connection and neutral wire phase and line voltage single-phase residential consumer transformer neutral cut off asymmetric load current protective earth 

分 类 号：O17[理学—数学]