Ground-fault protection based on active component of zero-sequence current in resistance neutral grounded distribution systems

A new principle of ground-fault protection for resistance neutral grounded systems is presented. Unlike previous work. the principle realizes selective ground-fault protection by getting the active current component that is resulted from the neutral resistor and only exists in the faulted line. Obtaining of the active current is presented in detail. On the basis of this principle, a selective ground-fault protection system and device have been developed.