We are using the ade7754 to measure the energy in 3 phase nets. In rare occasions we need to do this in a net without neutral connection (VN). AN-639 figure 16-4 derives a common source from 2 phase A & B. For the ease of configuration/product design, I wondered if it would be a good idea to create a virtual neutral (by means of tying 3 resistors, one for each phase, into a star point) and use this as reference point for the voltage measurements of the 3 phases. How would this affect the measured voltages/energy? How is this virtual neutral best constructed?
Thanks for the advice,