Predictive Harmonic Study

[tonyflair]

I'm considering an industrial distribution system which has a variety of harmonic producing equipment. I am interested in predicting the effects of these harmonics on the power system.

With the use of software, is it possible to predict the properties of harmonics in a system ? If so, how would one go about doing so.....more specifically, how does one determine harmonics only knowing cable, transformer, motor, and typical bus loading information. Would one have to consider every piece of harmonic producing equipment by itself (example - variable frequency drive) and determine it's harmonic output under various conditions ?

Do actual harmonic measurments have to be taken to see their effects on the system ?

The results of this project would determine if equipment is needed to minimize harmonics.....after actual measurements throughout the system are taken and compared with the calculated (measurements have not been taken as of yet because of $$$).

My knowledge in this field is weak, but I'm very eager to learn....so any help would be much appreciated.




harmonics on a power system when harmonics creating equipment is added. By predicting the harmonics, EPI can recommend ways to minimize the harmful effects. Once the equipment is online, actual harmonic measurements can be taken to ensure proper operation.

 

[Skogsgurra]

This is something you should talk to a consultant about. It is good that you are eager to learn, but there are many things to consider and someone who is learning tends to emphasise the wrong aspects. A seasoned EE that specializes in power quality issues is what you should consult with. And be prepared to pay $$$. What you pay now will be gained many times in the future.

 

[ePOWEReng]

There different ways to analyze this problem, but I would develop a model of your system in ATP or similar computer modeling software. Once the system is modeled you can look at the harmonics that each piece of equipment on your system is creating and make sure that you are not going to interfer with other equipment on your system. You should also interface with the local utility let them know what you are planning to do and see if they have any concerns. You also need to get system information from the utility for your model. If the equipment you are installing looks like it may have adverse effects on your own equipment or might cause a low harmonic power factor for your total load then you will need to install filters.