In which type of system is Line Current equal to Phase Current?

In a Wye system, the line current is equal to the phase current because of the way the connections are arranged. In a Wye (or star) configuration, each phase is connected to a common point (the neutral), and each phase winding is connected to a line conductor. Because of this direct connection, the current flowing through each phase is the same as the current flowing in the line conductor.

This characteristic is fundamental to the Wye configuration and is different from the Delta configuration, where the line current is actually the sum of the currents in the two connected phases. In a Wye system, since each line directly corresponds to a phase without any further branching, it results in the line current being equal to the phase current.

Single-phase systems, while straightforward, do not use multiple phases, so the concept of comparing line and phase current is not entirely applicable. In a mixed-phase system, the different arrangements could lead to varying relationships between line and phase currents, making it less straightforward.

Thus, the defining characteristic of the Wye system leads to the conclusion that in such a setup, the line current is indeed equal to the phase current.