Research On Selectivity Leakage Protection Equipment For Coal Mine High Voltage Power Supply System

Selectivity leakage protection is when the electricity net happened leakage fault , it can selectively give out fault signals or switch off fault branches, and out of fault branch works in gear. This is convenient to find out fault branch, search for fault point and so on, which improves the reliability of suppliment.Through research of tradition protection I make a discovery that in tradition protection automation come after compensation eliminate arc cycle's use diminishes the distinction between abort routes and nonabort routes at the same time it has important value. This make it difficult to achieve the protection purpose for selective leakage protection.This design compared the reasons what said above and draw the following conclusions: zero power current magnitude that through fault branch equals the add magnitude of infault branch and through neutral point resistance power current. Direction is from branch to generatrix. And infault branch zero power current magnitude is only own leakage resistive current. Direction is from generatrix to branch. We improved the zero phrase power current protection principle and made out VAR high speed SCM and CAN bus technology base on this theory, which achieved much better outcome.