Kwh Vs Kvar In A Power Distribution System

[AB2005]

Hi Friends;

 

In our 380V power distribution system, there is an energy analyzer installed on mains incoming just after transformer. the reading of EA is as following;

 

1) Kwhr = 1910000

2) Kvah = 1986000

3) Kvarh = 502500

 

Kwhr/Kvah reveals that the average power factor remains at 0.96. But I could not understand that only 0.04 difference of power factor (between average PF and unity PF)resulted the 502543Kvarh reactive power flow from transformer. Can any body explain it?

[marke]

Hello AB2005

 

Draw a right angle triangle.

 

Along the base line, you have the KW

The vertical is the KVAR and the hypotenuse is the KVA

 

At a power factor of 0.96, the angle is arcos(0.96) = 16 degrees.

 

The value of the KVAR is equal to the KVA times sine(16) which comes out about right.

 

NOTE this assumes a constant load factor.

Where the load is variable, it is possible to accumulate KVARH, KWH and KVAH that do not add up or equal to the average.

 

Best regards,

Mark.