How to determine what type of harmonic flitering to use?

[keithc]

We are going to be installing several new printing press lines , all using variable speed AC drives. We are also having to supply new 11kv/415v transformers. We estimate total power of transformers to be around 1900KVA. We are put off by the cost of 'active front end' drives , and were thinking of autotransformers to sort out the harmonics. Any body have any other ideas?

 

[bartos]

6/30/00<br>One may use passive harmonic filters, active harmonic filters, motor drives with phase shifting transformers (rectifier or pulse transformers), and some combination of phase shifting transformers with passive harmonic filters. However, the cost analysis comparison study is recommended since all alternatives to the active front end motor drives have their weak sides, e.g. transformers burn, passive harmonic filters can create resonances, active harmonic filters are costly (but do good filtering).

 

On your problem on the printing press line.<br>I am presently exsperimenting with power factor<br>improvers.I have several single face and 3 phase <br>unit in the field. So far power savings are<br>over 30%. At a truck stop in NJ I brought the Kwh<br>use down from 11000+Kwh to 7500 Kwh. [ 30 days ]<br><br>Fritz

 

[deeveeyes]

Unless the drive loads are varying throughout the load cycle, passive filters across the loads should give good results. One needs to understand the level of harmonics by actually measuring the harmonics and then decide if the harmonics are really harmful or can stay. PF can be improved on HT side by HT compensation. <br><br>Are there any statutory regulations in your country on the harmonic levels say to comply with IEEE - 915.