I want to create a neutral node at the output of a 3-phase Inverter for ACIM. Is it possible to do that by adding 3 resistors at the Inverter outputs and join them together to get the neutral node? What value of resistor is recommended? I need that neutral node to see the per phase waveforms on the oscilloscope. Can we call it a virtual ground?
1\$\begingroup\$ Why not calculate your per-phase voltages mathematically, instead of messing with your (unspecified) circuit? I think what you suggest would only really work if your load is perfectly balanced, and even then it's a very high-impedance neutral. \$\endgroup\$– HearthFeb 11, 2019 at 18:00
To provide a neutral point for an oscilloscope, a resistor network should be fine. The resistor value should probably be low compared to the input impedance of the scope, but high enough so that the resistor power ratings don't need to be too high.
\$\begingroup\$ If the peak phase voltage is approx. 300 V then a 100 K resistor would need to be of 1 W rating. Will that be good enough? \$\endgroup\$– scico111Feb 11, 2019 at 19:46
1\$\begingroup\$ I think that would be ok. \$\endgroup\$– user80875Feb 11, 2019 at 21:36