Glossary of Motor Terms
Three-phase currents and mutual relations
A brushless motor using a permanent magnet has three-phase winding, and these windings are often connected in a Y shape. The figure below explains the operation of the three-phase currents iA, iB and iC flowing through the windings. Three-phase current is not always perfectly sinusoidal, but when using a Y-connection the sum of the currents in each phase is always zero.
iA + iB + iC = 0
