Research on Countermeasures of Inrush Current in 10kV Distribution Network Line

The number and capacity of distribution transformers on the 10 kV distribution network line are increasing. In the process of voltage recovery after no-load closing or fault removal, the distribution transformer will generate magnetizing inrush current. The magnetizing inrush current generated by multiple distribution transformers is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$s$</tex> uperimposed on each other, so that the magnetizing inrush current on the line increases. The intelligent switch can not identify and distinguish the magnetizing inrush current and the fault current, which will lead to the misoperation of the overcurrent protection of the intelligent switch and expand the power outage range. In order to ensure that the equipment can work stably when it is put into operation, a composite voltage blocking overcurrent protection is proposed to avoid inrush current measures and avoid the misoperation of relay protection of 10 kV distribution network line switch.