Why is that we desired our induced voltage to be a sine wave when working with 3 phase induction machines?

 

As opposed to what other waveform that would transfer efficiently through transformers?

 

Why is that we desired our induced voltage to be a sine wave when working with 3 phase induction machines?

An AC motor rotates at the speed determined by the fundamental sine wave frequency and the number of motor poles. Anything other than a sine wave has harmonics at higher frequencies which do not contribute to the fundamental magnetic field and thus to driving the motor. The energy from these harmonics is dissipated as waste heat in the motor which is obviously undesirable.

 

The source voltage is a sine wave--that is what our electric utilities generate--as a result the induced wave will also be sine wave.