leading or lagging power factor

Thread Starter

gisdude

Joined Oct 30, 2008
16
Hi all, sorry to revive this topice, but I have a question.
If a generator is producing 500MW and 200MVAR, it the generator?
1. Leading
2. Lagging
3. Underexcited
4.Dropping

Intuitively, I would say "Lagging", but if I make a power triangle from these 2 quantities, HOW DOES ONE TELL IF IT'S LEADING VS. LAGGING?

You can get the cos of the angle, but that doesn't tell me if current is leading or lagging, right?

Many thanks
 

Thread Starter

gisdude

Joined Oct 30, 2008
16
Reactive power, typically, is less than Real power. If you have a lot of VARS on the system, then you're going to be losing Real power. That's why on transmission systems the utility will install capacitor banks, 600kvar, 1200kvar, etc, to keep the power factor closer to unity.
 

Ramussons

Joined May 3, 2013
1,026
Hi all, sorry to revive this topice, but I have a question.
If a generator is producing 500MW and 200MVAR, it the generator?
1. Leading
2. Lagging
3. Underexcited
4.Dropping

Intuitively, I would say "Lagging", but if I make a power triangle from these 2 quantities, HOW DOES ONE TELL IF IT'S LEADING VS. LAGGING?

You can get the cos of the angle, but that doesn't tell me if current is leading or lagging, right?

Many thanks
500 MW is the Real Power (MVA Real) and 200 MVA is the Reactive part (MVA Reactive). The power produced by the generator would be 538.5 MVA.

With the given input, it will be not possible to say whether this Reactive Power is Leading or Lagging. Generally, with loads like Motors and Transformers, it will be Lagging.

I see no relation to the other 2 options given ....... Underexited; Dropping (what does this mean?)

The only connection with "exitation" is that "an over exited Synchronous Motor exhibits a Leading Power Factor" and use of such are known as "Synchronous Capacitors".
 
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