Power generation, operation and control

[sparkview]

Dear all,

I'm looking into some information to prepare a refreshment presentation for our grid and powerplant operators.
There may be some misunderstanding related to the operating philosophy in the normal state. e.g., when to change the power factor, when to control voltage with generator power flow, and when to use OLTC for voltage adjustment.
I was wondering if anyone has experience in giving guidelines and if a guide exists, that can be used as an aid in on-the-job refreshment training in a simplified, straightforward way.

In advance, many thanks for any information.

 

[bacon4life]

In my region each utility uses guidelines that are specific to certain equipment and locations.

 

[RRaghunath]

Your query is specific to operation of OLTC of Generator step-up transformer (GSUT), I suppose.
OLTC of GSUT is operated initially (prior to synchronising) to bring the GSUT LV side voltage within +/-5% of generator terminal voltage.
Once the generator is synchronised, OLTC has no influence (or negligible influence in case the grid happens to be weak in the region) on generator voltage. Instead, any change in the GSUT tap position results in change in the VAR flow from generator, change in the generator power factor in other words.
It is well known that generator stability is better when it is operated at lagging power factor (supplying VARs to grid) and some utilities operating procedures include use of OLTC to ensure generator always operates with lagging power factor.