MMF distributions in a 3-phase ac machine

WAVE SPACE DISTRIBUTIONS

Under balanced 3-phase sinusoidal excitation of an ac machine, the field space distribution produced by each phase is a sinusoidally distributed pulsating wave centered in its axis. The ABC [RGB] axes are 120^o apart. The resultant field (in black) is a traveling wave of constant amplitude moving at a speed which corresponds to the excitation frequency.