Why does Triplen Harmonics Exist?
The Rotor has a shape of a magnetic that has a single axis – 180 degrees.
If sufficient coils exist within the exciter – the magnetism crosses 2 times every 180 degree rotation.
The stator is divided into 3 divisions – such that maximum intensity of the magnetic – passes each set of coils every 120 degrees.
360/120 = 3
All is well, if all the loads are balanced and symmetrical.
During steady state X conditions the – 3 harmonic is not noticeably. It however does exist on a T100 A fault.
That Asymmetrical Fault – 100 percent of the AC Fault conditions. When a 1 Phase to Neutral Fault exists the DC components equals the AC components.
This is also referred to as a DC offset of the systems that originates from the system rotating sources.
Components is a brief period of time the machines can convert all the mechanical energy to electrical energy.
If has a rapid time constant as the metals of the system heat up very rapidly – increasing R, thus lowering the capabilities to offset.
This 60 year schetch is from a ANSI NEMA – General Electric les training manual. It also provided such documentation to the major university, complete with test equipment for a “System”. Generators, Motors, Transformers and Switching Devices.