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I am new to this forum. I am an Electrical Engineering student working on a project. I am using Matlab Simulink/Simscape to perform simulations.

Currently, I am working on a three-phase rectifier. (see photo below)

I am not getting the desired waveform on the output. Does anyone have any advice?

I know my input phases are current. I viewed them on the scope and they are 120 degrees shifted.

enter image description here

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  • \$\begingroup\$ Well what do you get and what do you expect? At least I would not connect generator output Phase to Neutral via some mysterious rectifier symbol. What is the symbol? \$\endgroup\$
    – Justme
    Apr 19, 2020 at 23:25
  • \$\begingroup\$ @Justme that is SimPowerSystem's diode symbol. it also represents an included "snubber network" \$\endgroup\$
    – user16222
    Apr 19, 2020 at 23:26

1 Answer 1

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The problem is you are shorting the supply.

What you have is the NEUTRAL of the supply (associated with the SimPowerSystems reference) and the NEGATIVE of the rectifier commomed together. Essentially all phases are shorted via one diode.

In practice a rectifier will produce a mean voltage who's differential voltage is \$\ \frac{3\cdot \sqrt{6}}{\pi}\$ that of the RMS,for 3phase systems thus a 230V phase ~ 540Vdc, DIFFERENTIAL. The common-mode voltage with regards to the NEUTRAL of the supply is +-270Vdc (for a 230V phase).

How to fix? leave the rectifier negative floating.

enter image description here

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