Hi Guys,
I'm looking for the best ideas for implementing an AC power instrumentation front end for a microcontroller or FPGA.
What I need to accomplish is to measure 50-60HZ AC in the range of
120V upwards of 600VAC with about 1% accuracy, TRUE RMS. I need to extract:
- Voltage
- Current (via current transformers)
- Frequency
- Power Factor
- Phase difference
This needs to work with reasonably distorted waveforms, like what might be found in small generators driven by engines. I also need something that will work for single phase or for 3phase and be scalable to instrument up to two 3-Phase sources.
There are a variety of ways to go about this but I'm looking for something that is very flexible and can adapt to a variety of voltage configurations (line to line, or line to neutral) and is very low cost.
I would guess that it might be similar to the best practices that would be used in the front end of True RMS DMMs or DAQ cards with AC inputs? I know there are also energy metering chips out there, but they are rather expensive.
Thanks for any ideas!
PW