Voltage drop in three phase bridge rectifier

Thread Starter


Joined Feb 8, 2009

Does anyone know how much voltage is dropped when rectifying a three phase AC Voltage into DC Voltage. I know its 2 times the diode forward voltage drop for 2 phase rectifier but wasn't sure for 3 phase rectifier.

For, eg, for 10 VAC RMS rectifying using bridge rectifier with 0.7V forward voltage drop for each diode, you will have total voltage drop of 1.4V (2 times 0.7). But would be the formula for 3 phase rectifier where 6 diodes is used?

Thanks you.


Joined Mar 6, 2009
In principle with the 3-phase equivalent of a single phase rectifier bridge there are still only two series diodes conducting in any particular part of the AC cycle.

There is a condition - commutation interval - during which three diodes are momentarily conducting (not all in series). The latter is probably not of interest or necessary to consider in a simple design case.

There are certain poly-phase rectifier circuit options in which only a single diode drop is encountered. For rather more specialized applications.