davva
Marine/Ocean
- Sep 27, 2004
- 99
A power system model shows that a clients plant will be non compliant with a chinese harmonic code (4% THDv and 3.2% MIH). The primary reason for this is a large 12 pulse drive used to start a compressor, it takes a couple of minutes to run the synchronous motor up to full speed after which the VFD is bypassed.
All the components of the system are on order so I'm told it to late to change anything. Instead the drive vendor is advising that the drive will be compliant with IEC 61000-2-4 Class 3 equipment (allows 10% THDv). Conveniently lowering the bar?
My question is.... bearing in mind the short time use of the VSD, are 11th and 13th harmonics primarily associated with heating effects? or are there sited cases when their presence has had other detrimental effects?
All the components of the system are on order so I'm told it to late to change anything. Instead the drive vendor is advising that the drive will be compliant with IEC 61000-2-4 Class 3 equipment (allows 10% THDv). Conveniently lowering the bar?
My question is.... bearing in mind the short time use of the VSD, are 11th and 13th harmonics primarily associated with heating effects? or are there sited cases when their presence has had other detrimental effects?