A more industrial/commercial angle

There is nothing published yet. As soon as some of these discrete VT type sites get up and running, I’ll try to get a few to set up simultaneous monitoring using both methods to get some data regarding accuracy vs the true voltage/phase reference. This can be done on the same device - one CT monitoring the circuit with a discrete voltage/phase reference, and another with a phase shifted reference from a different phase.

I have done it using my US split phase system where the other phase is 180degrees, but the voltages are related and the phase is exactly 180 degrees. But as a result I know the IoTaWatt phase shift algorithms are working, so it’s just a matter of degree - so to speak.

If the method proves to be accurate enough to be of interest to users, then I would enhance the user interface to support configuration. In the meantime, the way it can be done with the existing utility is to configure the CTs as “generic” and add 120 or 240 to the phase parameter.

For instance, when you configure an SCT013-000 CT, it has an implied turns of 2000 and a phase of 3. So if you were to install it on a phase that is shifted 120 degrees from the primary reference VT, you would configure it as:
image
The phase correction software would then slide the voltage samples an extra 120 degrees under the current samples.