How to design a power factor meter

[sapna.dudani@gmail.com]

I have to design a power factor meter , with range 0-500 VAC, and maximum current 0.1 amps, and output voltage being 3.3 and 5 volts.....
can any please help me with the links to find a reference diagram for power factor meter

 

[umesh49]

Do you intend to use a microcontroller? is your current and voltage signals are expected to be sinusoidal?

 

[sapna.dudani@gmail.com]

yes the current and voltage signals are expected to be sinesoidal....
yes i can do that using microcontroller..... can anyone please help me with any links to reference designs.....

 

[NIKO BELLIC]

I guess you're using a microcontroller to design a power factor meter. Recently, I've done a project on power factor correction which includes measurement of power factor too. Refer to the Chapter - 4 of my report attached below. Hope, it solves your problem.

 

[sapna.dudani@gmail.com]

hello sir your report is very useful for my project thankyou...
but i have some queries
for example when we design any meter for single phase or three phase we connect the pt between R and N , Y and N, B and N , we take N as the reference ....
can you please help me with the connection of pt between R and B in your report .....

 

[sapna.dudani@gmail.com]

Do you intend to use a microcontroller? is your current and voltage signals are expected to be sinusoidal?

yes sir i am using msp430g2453 and current and voltage signals are expected to be sinusoidal

 

[NIKO BELLIC]

.
can you please help me with the connection of pt between R and B in your report .....

When there is a pure resistive load, the phase angle between current and voltage waveforms must be 0 degrees. To ensure this, we connected PT in between two phase lines. If PT is connected between any phase (R,Y or B) and neutral (N) then there would exist an offset phase angle of 30 degrees between current and voltage waveforms, which will further ruins the calculation of power factor, since CT is carrying phase current.
Refer to the 22 slide of the following link..
Phase Relationships Between Line-Neutral and Line-Line Voltages