RE: Three phase conversion In Rush current Concern.

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Leigh Copp" <Leigh.Copp@xxxxxxxxxxx>

True, a drive designed for 3 phase won't (good analogy on the mechanical
inertia as a filter by the way - a lot of people miss the dualism),
however one properly designed for single phase would be ideal.

A current source inverter (CSI) based drive (9-1/2 tenths of the drives
out there are VSI based) makes a great single phase to three phase
converter, because the DC link inductor is sufficiently large that the
120 Hz ripple is almost completely eliminated.

Leigh

-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: September 30, 2006 8:10 PM
To: tesla@xxxxxxxxxx
Subject: RE: Three phase conversion In Rush current Concern.

Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>

At 11:26 AM 9/30/2006, Tesla list wrote:
>Original poster: "Leigh Copp" <Leigh.Copp@xxxxxxxxxxx>
>
>Hi Jim
>
>If and when you add the generator to your converter, the output will
>be about as perfect as perfect can be, and this problem will be a
>thing of the past.
>
>Regardless of how balanced your three phase ends up however, of
>course we know that power in is going to be somehwat more than power
>out, because even state of the art rotary converters (M-G sets) are
>less than 85% efficient. (A good drive will beat this without any
>moving parts BTW).


But a good solid state drive (while efficient) won't do as a good a
job turning single phase into 3 phase (in terms of ripple) because
the MG set essentially is using mechanical inertia as the low pass
filter/energy storage medium in the "DC link" (the DC just happens to
be unidirectional mechanical motion here).