Phase determination in 3 phase circuits

[vinay.hn]

Hi!
I'm working on a 3 phase induction motor. I need to measure the RMS values of three phase voltages, and single phase current which further feed power to the induction motor. I've implemented the true rms measurement (sum of squares method) algorithm for RMS value calculations and readings are fine. For calculation of power I need to multiply the current with the corresponding voltage. But I don't know in which phase the current is being drawn.
So, in case of 3 phase circuits, is there any algorithm to determine the phase in which the current flows? One point to keep in mind is that the load will always be inductive and the current always lags the voltage in that phase.
Please help.

Thanks

 

[NoTime]

You need the phase angle between voltage and current.
It's not enough to know that it lags.
Pick any winding to measure both.

 

[ravenprp]

for reaching out! In order to determine the phase in which the current is flowing in a 3 phase circuit, you can use a phase sequence meter. This device measures the phase sequence of the three phase voltages and can determine the phase in which the current is flowing. Another option is to use a power analyzer, which can not only measure the voltage and current, but also calculate the power factor and phase angle to determine the phase in which the current is flowing. Additionally, you can also use a clamp meter to measure the current in each phase and compare the readings to determine the phase with the highest current, which would indicate the phase in which the load is connected. I hope this helps and good luck with your project!