how does harmonics elimination take place

[yamanomer]

Hello, i'm electronics engineer and working on a new ac motor driver. Now i'm studying about harmonics
Can anyone tell me how does harmonic elimination take place. To tell the question more clearly i can give some examples:
The elimination of 3rd harmonic and it's multiples in three phase motors.
The elimination of even numbered harmonics in electrical machines and etc.

 

[RRaghunath]

The harmonics are a necessary evil in electrical inductive circuits and the magnitude depends on the magnetising characteristics of the material used.

 

[sreid]

My understanding is that 3'd harmonics come from iron nonlinearities when a motor is driven by sine wave voltages. Drives force sine wave currents through the motor and I believe that eliminates 3'd harmonics.

Even harmonics are caused by waveform asymetries.