Harmonic waves 1

[kbowers]

Are there regulations that require harmonic wave dampers or filters to be used with high power industrial lasers (6kw)?
I would like to buy one and am wondering if the manufacture is responsilbe for some sort of countermeasure or if i am.

 

[electricuwe]

A difficult question, the answer depends on the following:

Where is you factory situated ? Standards for electrical equipment differ a lot in different countries.

What is the input power of your laser and to what voltage is it connected.

What does does the contract between you and the supplier of the laser state on that topic ?

What is the short circuit power available at the point where the laser power supply is connected ?

Can you decribe the type of rectifier used in your laser power supply ?

You should consider that harmonic problems are generally problems where the whole system and not only the component has to be considered.

You would get better answers, if you would be able to describe your problem more specific instead of posting the same question in several forums.

 

[kbowers]

I am located in the US. I will connect to 60hz 3 phase AC 450v 100KVA. I know that the laser produces -25,000 Volts. That is all I know. I am sorry that I can not provide the info you need. I am simply wondering whether I should worry that my supplier is not meeting some regulations about this problem which I am not aware. I am looking for help and do not know where to find it so I posted in various forums. That is the point right?

 

[electricuwe]

I 'm not familiar with laser power supplies, but with power electronics in general so I just can give you some general hints. Maybe someone else in this forum (I guess this one is the best for that topic)can provide further assistance.

Power electronic equipment in that power range today ususally uses DC-voltage link designs. The rectifier in this type of power supply usually doesn't cause a bad fundamental power factor but causes harmonic currents.

On VFDs of the same power rating some inductors in the input line have to be used to reduce this harmonics. These inductors are usally not supplied as integral part of the drive.

Further measures might be necessary depending on system configuration.

 

[redtrumpet]

Most members browse several related forums in the electrical area, so you only need to post in one forum and we'll find it. By posting more than once, you run the risk of starting multiple threads on the same topic as members reply to different posts. To prevent this, duplicate posts are generally red-flagged by members and removed by the site administrator. Please don't repost your duplicates if they are removed.

 

[dpc]

I think the short answer to your question regarding harmonics is that this is your responsibility. The manufacturer does not know what type of electrical system the equipment will be connected to.

My suggestion is to have an electrical engineer develop a simple one-line diagram of your electrical system including transformer sizes & impedances as well as the utility impedance data. You can then send this to the laser manufacturer and ask that he provide whatever filtering equipment is necessary to maintain the harmonic levels at the point of coupling with the utility (or wherever) within the requirements of IEEE 519. You can have the supplier assume your existing system has no harmonics, or you can measure the actual harmonics and provide this data to them.

If this is a sole source purchase, you should discuss this with the supplier and negotiate a solution. If it is a competitive bid, you need to get this requirement into the specifications.

Hope that helps.

dpc

 

[kbowers]

Thank you dpc that was exactly what I was looking for.

 

[jbartos]

Suggestion: Please, notice that the manufacturer does not necessarily provide harmonic compensation. He may ask the buyer to have the interfaces adjusted as required, e.g. according to power supply. For example, if the buyer uses a dedicated power supply, then the voltage total harmonic distortion (THD) can be higher than IEEE Std 519 stipulated 5% limit. It may happen that at third party will be adjusting interface parameters.