Dear Jagabar S. Mohamed Ali
Firstly, the CMV is defined as the voltage between the neutral point of the isolated star connected load (n) and the grouded point of the supply (g). If you use an inverter to supply your load (motor), you can measure the CMV between the point (n) and the mid-point of the dc-bus (o).
In order to obtain the CMV waveform in your matlab model. you should use voltage measurment tool from the power system toolbox or simscape toolbox to measure the voltage between the points n and o.
Best regards
The question is unclear, common mode voltage is a voltage gained on conductors or nets that are exposed to an interfering electromagnetic field and it is built with same polarity on all conductors. The normal practice to get rid of common mode voltage is to use differential mode (contrasted to single-ended) measurement where an op. amp. circuit receives signal from 2 wires (go & return) of the signal and by differential amplification, the common mode voltage is dropped out and the real signal only is amplified (or just filtered with gain= 1)
Now, I can't join MATLAB/SIMULINK with common mode voltage to understand your issue?
How to measure common mode voltage using machine (induction motor)equivalent circuit?
Where do you want to measure the Common mode voltage?At the motor terminals?How are giving input to the motor?Is it through a Source or Converter?
You can add parasitic Capacitances between the motor terminals and Earth to measure ,Generally this Capacitance will be in the range of nano farads offering very high impedance.
Dear Jagabar S. Mohamed Ali
Firstly, the CMV is defined as the voltage between the neutral point of the isolated star connected load (n) and the grouded point of the supply (g). If you use an inverter to supply your load (motor), you can measure the CMV between the point (n) and the mid-point of the dc-bus (o).
In order to obtain the CMV waveform in your matlab model. you should use voltage measurment tool from the power system toolbox or simscape toolbox to measure the voltage between the points n and o.
Best regards
You can simply sum the terminal voltages, especially if you don't have an access to the neutral point in your simulation model.
If you do not have access to the star point. You can create a virtual star point using three resistances connected In star and to the three phase voltage.
The cmv is the voltage between the virtual star point and the inverter neutral
for single phase inverter measure the two point of output voltage (VA0, VB0) refer to ground and sum them, then divide by two. For three phase inverter measure the (VA0,VB0,VC0) refer to ground and sum them, then divide by three.
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