Electrical Machine Theory

[Cerkit]

Hi,

Does anyone have a link to a brief explanation of subtransient reactance of a generator? My understanding is that under a fault conditions the flux changes in a synchronous generator which results in the increased current contribution and an effective reactance X" is given for a machine which gives an equivalent current while assuming the nominal machine voltage.

Can anyone point me to some literature to help me better understand/explain what occurs?

Thanks

 

[davidbeach]

Anderson's Analysis of Faulted Power Systems is a great reference and includes a chapter on synchronous machines.

 

[dpc]

+1 on this reference. Assuming constant excitation, fault contribution from synchronous generator decreases with time. We approximate this by using different reactances at different points in time defined by the generator time constants. You can also Google Park's Transformation for deeper background.