Line Droop Compensation - incorrect term?

[66661]

Hello.

I am familiar with the term Line Drop Compensation but I've seen mentions of a term Line Droop Compensation which I think is a misnomer and has emerged by mistake. Afterwards, it seems to me, this erroneous term has been adopted by others and so the mistake has multiplied. It is easy to understand why such a mistake could exist since as far as I know there is a term Voltage Droop which describes a slope in voltage but from what I've seen in textbooks the correct term is Line Drop Compensation (LTC).

Does anybody know of a "Line Droop Compensation" that would mean something different than "Line Drop Compensation" or is it just a misnomer?

 

[waross]

Droop as applied to generator control is very close to proportional band or P in a PID controller.
For a generator with a synchronous speed of 1800 RPM and a no load speed of 1854 RPM the droop is 3%
1800 RPM x 1.03% = 1854 RPM
The proportional band of the same speed control system will be 1854 RPM - 1800RPM / 1854 RPM = 0.029%
Or 3% proportional band plus 3% offset based on the full load speed.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[DTR2011]

It may be just as you describe, LDC = Lind Drop Compensation, as applied to Xfmr OLTC or Voltage regulator controls and settings. Often times I hear and read "Recloser" as "Reclosure", or "Reclosures". In my case, I believe this is simply a local dialect and or misunderstanding of the correct term/function used by some in the field. There are many tools and electrical devices that seem to have been renamed terms not spoken in polite company.

When I think of Droop, it is generally in terms of generator controls.

 

[66661]

I know about Droop in generator controls, I also know what a voltage droop would mean, but what I want to be sure about is that the term "Line Droop Compensation" is erroneous. When I do some research in Google I find "Line Drop Compensation" to appear in sources like ABB, GE and textbooks. Also there are patents of GE and Westinghouse that use "Drop" and not "Droop". In contrast "Line Droop Compensation" appears only from untrustworthy sources.

 

[jghrist]

If it is used in the context of voltage regulators, then the term is misused or a typo.

 

[ScottyUK]

I agree with jghrist, it is a misnomer for Line Drop Compensation.

A recloser is a piece of apparatus, while reclosure is the operation performed by a recloser. Both are valid words but have different meanings.

 

[crshears]

Fer sure should be drop in this context, not droop...and why oh why did some nincompoop where I work start writing about how to "in service" something instead of commissioning it? The mis-use has caught on like wildfire / "gone viral," just like nobody seems to care that a 44 kV feeder would probably not be sectionalized with an "air brake switch" ... and on and on it goes.

True story:

A co-worker once used an incorrect spelling in a log item, which error considerably distorted the intended meaning. When I pointed it out to him, he retorted, "Nobody cares about spelling anymore; it's not a big deal, so shut your pie-hole."

When I next created a log item in which I reported on something he had told me, I deliberately spelled his last name as "Dung" instead of "Dunn." When he tore a strip off me about mis-spelling his name, I retorted, "Nobody cares about spelling anymore; it's not a big deal, so shut your pie-hole."

CR

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

 

[66661]

There is a special circumstance that complicates the issue here. Some may argue (and they already have) that what happens over the line is more like a droop than a drop. And this makes the "virus" spreading easier. Some engineers would argue that droop is exactly the word to describe the phenomenon and further argue that "droop compensation" makes perfect sense. The fact that droop is an OK word to describe the phenomenon and technique to counter it makes it even a bigger problem when you have to sort out right from wrong. Another thing I was concerned about was whether both terms (one with the "droop" and another with the "drop") exist but mean different things. My research so far did not find any solid evidence that Line Droop Compensation is something more than just a misnomer for Line Drop Compensation. However I could find things like this:

http://www.hpcnet.com/index.php?opt...tage-regulator&catid=63:generators&Itemid=119

 

[ScottyUK]

re. link above

I've spent many happy days working on a pair of WTA-300B's which didn't want to play nicely with the generators they were controlling. Quite a simple AVR design compared to the computerised types of today, but repairable and maintainable with fairly modest test gear.

 

[jghrist]

Some may argue (and they already have) that what happens over the line is more like a droop than a drop.

Except in the regulator context, we aren't referring to a voltage sag or droop. We are compensating for the I·Z voltage drop along the line.

 

[66661]

jghrist, I got a little lost, which is the regulator context where droop is used and how does the droop term come into play there?

 

[jghrist]

I'm just saying that if the term droop is used in a voltage regulator context then it is wrongly used.

 

[waross]

I believe that jghrist is referring to rural distribution type voltage regulators and not the Automatic Voltage Regulators used with alternators.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[racookpe1978]

Those of us not in the industry are wondering: What then, is the proper term then for the 10% excess cable length caused by the droop in the power lines between high-tension towers? 8<)

 

[waross]

Sag.

Bill
--------------------
"Why not the best?"
Jimmy Carter