Does AFE Drive as good as manufacturer says?

An Active Front End (AFE) Drive installation where shutting off the filter would also shutoff the variable frequency drive (VFD). This is truly a serious and widespread problem that the AFE Drive manufacturers don't want anyone to know about. In fact, they actively promote their AFE 'low harmonic drives' as the ultimate solution. I chuckle when I watch one elaborate video produced by an AFE drive manufacturer that properly highlights harmonics as a serious problem but makes no mention of the fact that the AFE solution they promote will very often make the situation much worse rather than better. Unfortunately, it is the poor customer that believes their claims that will suffer with the consequences.

I am aware of a situation where the only solution for the problem introduced by a parallel connected Active Harmonic Filter was to shut it off. An active harmonic filter installed in a manufacturing plant that built solar inverters and solar panels was causing a power supply in one of the solar panel testers to burn up due to harmonics at the 41st which were generated by the active harmonic filter. This was occurring despite the fact that the VTHD at the site was < 1%. Well within any regulatory standards. After the manufacturer's efforts to adjust the LCL filter by supplying another inductor had failed, the only solution was to turn it off with it becoming a very expensive 'boat anchor'.

I believe the Active Front End Drive is being replaced with a standard 6 pule drive and a passive filter. It was not possible to disable the AFE functionality on this unit. This is a very common problem, although not usually to the level of destroying revenue meters in such a short time. Often problems are blamed on other equipment, sensitive design etc. It is common in some areas, to see flow meters solar powered to mask common mode problems.

AC Drives

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