RTDs placement in stator winding

[Sargardani]

Is it acceptable to put RTDs between top and bottom bars of different circuits of the same phase in a hydro electric generator? I am looking for the pros and cons of doing so in comparison to placing the RTDs in between the top and bottom bars of the same circuit of the same phase.

This is a six circuit generator i.e 2 circuits per phase.

All info is highly appreciated.

Thank you all.

Sarg

 

[electricpete]

Start by what can cause localized overheating?
A – Core problem
B – Cooling problem
C – Strand insulation breakdown / conductor eddy
D – Unbalanced voltage
E – Shorted stator turns????

I don’t see where A – C care about which circuit or phase is being monitored. A and B only care about physical location.

D will affect phases differently but affect all circuits within a phase the same.

So far no preference for same-circuit or different circuit.

The only mechanism I can begin to conceive of which might have preference for one circuit over another is shorted stator turns. But to it seems very unlikely this condition can exist for long without causing an electrical fault => not even worth considering for temperature monitoring.

Based on the above I don’t see any reason to prefer one over another.

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[edison123]

It is a good practice to distribute the RTD's circuit wise (to detect loss of a parallel circuit, which may not be necessarily picked up by differential protection unless it is specifically configured to cover all parallel circuits) as well as around the stator to get to an overall thermal map of the machine. Also, it is advisable not to place them near the cold air inlets for they are not hot spots.