Multiple voltage regulators along distribution line

[chuckd83]

We are in a remote area and have installed miles of distribution line and have voltage drop issues. We have installed voltage regulators and capacitor banks to mitigate the situation. What is the best approach to setting the tap change delay at the voltage regulators?

First thoughts are set the one closest to the source with the lowest delay (30 seconds) and add 15 seconds for each subsequent regulator.

 

[cranky108]

That's a good way to make the regulators move a bunch. Why not the other way? Make the source regulator move first?

 

[chuckd83]

What do you mean? That's what I proposed.

 

[crshears]

Hi chuckd83,

If you get your wires crossed you can shortly expect to be confused......and I'm not entirely sure I understand what cranky108 wrote, either.

I'd think the very first thing to do is to set up the voltage regulation bandwidths at the source station, taking in to account both the real and reactive characteristics [if applicable] of how the composite load of all feeders changes over the course of the day. Doing this ensures the best possible match to the summed loads the source has to supply.

Then and only then do you work your way down the line or lines in question, applying the scheme you propose...although I'd probably only add 5 seconds per regulator after the first one.

Incidentally, you haven't mentioned if the down-line caps are switched in and out of service...

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[Mbrooke]

I know this was not mentioned, but my question has it be considered whether or not more distribution sources could be added? Generally I avoid more than 2 sets of regulators, and where need be I will boost the supply substation voltage first until the maximum amount of bandwidth is reached on the LV supplies before turning to inline regulators. Of course in theory it would be better to advance the inline regulators along with the substation for uniform voltage, but I have found this to be the most fool proof in none SCADA regulators.

 

[chuckd83]

CR, the cap banks are switched in/out of service based on
-low voltage, lagging/leading kVAR, and lagging/leading power factor. All three have a 60 second delay.
-high voltage with a 5 second delay.

Can you point me to band width calculations you mentioned?

 

[crshears]

Hello chuck, another department usually does that for us, but to my understanding it's performed using a type of network analysis factoring in all of the variables mentioned, plus a few I probably haven't thought of.

Perhaps others can be of further assistance...



CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]