ll large turbo generators are three-phase machines. Thus the best place to start describing the operation of a three-phase synchronous machine is a description of its magnetic field. It is also show that by coiling the conductor, a larger field is obtained without increasing the current’s magnitude. Recall that if the three phases of the winding are distributed at 120 electrical degrees apart, three balanced voltages are generated, creating a three-phase system. Now a new element can be brought into the picture. By a simple mathematical analysis it can be shown that if three balanced currents (equal magnitudes and 120 electrical degrees apart) flow in a balanced three-phase winding, a magnetic field of constant magnitude is produced in the airgap of the machine