Three Phase Power Meter Design

[zunda1958]

Hello, I'm using the KM34 Three Phase Power Meter Design Files.

Please let me know.

Using the Three Phase Power Meter Design Files in KM34
I want to use two CTs instead of three in a three-phase, three-wire AC circuit and use this library to find the RMS value of the currents, estimating that the remaining one phase is the sum of the currents of the three phases due to Kirchhoff's law, which is zero.
Is there any documentation for such an application?

Best regards.

[xiangjun_rong]

Hi,

Yes, you are right, based on the Kirchhoff's law, the sum of three phase instant currents is zero. But you have to consider the phase shift of the current transformer and the neutral current, so I suppose you have to use three current transformer.

Pls refer to the an13338.pdf from the link:

https://www.nxp.com.cn/docs/en/application-note/AN13338.pdf

Hope it can help you

BR

XiangJun Rong