ECE 4411 Air-Gap Power The power transferred electromagnetically across the air gap between the stator and rotor is called the “air-gap power”, or “gap power”. We will consider one phase as shown above.

ECE 4412 Active Power (Watts) Reactive Power (VARS)

ECE 4413 Power Components Active Power, P gap, supplies the shaft power output as well as friction, windage, and heat losses i the rotor. Reactive Power, Q gap, supplies the reactive power component for the alternating magnetic field around the rotor current. Reactive power is not dissipated, but is sinusoidal across the gap.

ECE 4414 Power Diagram for Air-Gap Power

ECE 4415