How to measuring energy after VFD

we will measure the three phase energy data after the Variable Frequency Drive (VFD) and its line frequency will vary from 20 to 60 Hz. so we can't measure the energy data after the VFD.

Here i have given our design inputs FYR. Kindly suggest your Part Number for this requirement and its operate in variable line frequency, not in fixed 50/60 Hz.

Design inputs:

1. Measuring method   = 3P3W
2. Vphase-phase          = 220-600 Vrms (using Resistor divider)
3. Iphase                       = 0-480Arms (using Rogowski/CT)
4. Line Frequency         = 20 - 60Hz (VFD output frequency)

Measuring parameters:

• Real power / Energy
• Apparent power / Energy
• Reactive power / Energy
• Individual phase voltage and current
• Energy pulse output
• Frequency
• Phase fault and sag Detection

Awaiting for your valuable reply.

Thanks in advance.