VFD Harmonics and Power Quality

[@laboratoriocotear1949]

TECHNICAL QUESTION I have "repaired" a heidenhain uvr150d power supply(75kw) and a need to do a technical question. The thing is I've found 4 igbt shorted and 2 400v caps broken, Ive replaced everything and checked for another broken components, I didnt find anything else malfunctioning. Its the firs time I "fix" this size of power supply. Ive connected it to the wall in the laboratory (3x 380V) and it worked fine the 5V and 24V. Then ive "shorted" the pins that enable the 650V DC bus and it generated it. The power fail led that was bright initially turned off and the READY UV led bright green. It was everithing fine. It worked well. But the problem is that I didnt use any filter or transformer or trhee fase capacitor (as the manufacturer recommends), so various home appliances (as 2 TVs 2 air conditioner boards and some cellphone power supply) exploted . Ive opened some of this boards and ive found 400v capacitors exploted, so there was a huge peak of voltage above 400V in the 220VAC line( maybe 800V peak). The answer is, are those harmonics natural to this size of power supply? The power supply is working fine and the harmonics its generating are normal? If I test it in the client machine with the appropriate filters transformers and capacitors would be ok? Or it may occur the same as here in the laboratory? Its the first time ive repaired this size so i dont know if it is OBLIGATORY the use of this filters.

[@johnson554671]

Thank you for showing the scope traces before and after. I had to spend an hour looking for this and at least the person posting this video had common sense to show graphically what the reactor does (ON BOTH LINE AND LOAD SIDE OF THE VFD) before and after.

[@ahmedelmasry7435]

Pleas I have one question. What difference between connected reactor on input VFD and Output VFD

[@ravigovande2922]

Great video! Can I please get the Text of this video? Thanks

[@Mark-sq8mh]

If I install the trafo at the output of the VFD instead as you show in the input (I have a single phase supply input and a 3 phase output VFD, in a house with a single phase network and a 3 pahses motor) will it filter the armonics or the effect will much less? is there a performance "number" in the datasheet of VFD to see how is good to avoid to create such armonics? thanks

[@brycejacobson4919]

At the time of this comment, this video is now 9 years old. Do VFD's produced now in 2024 still pull current in the same "gulp" way? Do the new ECM (electrically commutated motors) and LED's we are retrofitting everywhere cause the same harmonics?

[@camron2674]

Would it be practical to add line reactors at the service entrance thus eliminating line reactors at every VFD?

[@sabiriwayuser1]

How to select RL Series capacity according to motor capacity, suppose what's capacity of 5.5kw motor reactor.

[@jesterraj]

can a AC generator create harmonic distortion?

[@VFDscom]

Raj, No, generators will not create harmonic distortion.

[@donnots8218]

Raj Dann ac generators for backup power for say your house will have a level of total harmonic distortion. when buying a generator try to stay in the 5% THD or less to keep your electronics safe

[@clems6989]

I really hate to hear people say things like "VFD's create dirty power" or the VFD's Cause trash in the power system" The VFD doesn't create or cause dirty power. Everything that a variable frequency drive does is completely predictable. It is the designers job to make certain the installation is done correctly and these predictable patterns and waveforms are properly used.

[@aldringovindasamy]

Thank you, what a great explanation?

[@Fidrafunk]

Great video, this helped me a lot, thanks!

[@Ray-tu9yf]

I running 1HP motor with 3HP inverter drive. I measure the RST and UVW currents, which are not tally. (RST show 2.6: UVW show 1.8) In this case, which current should be use ?

[@greenspeed1735]

Very informative video

[@maniawan6789]

please can u guide me its my final year project

[@Eld0g5]

+mani awan what are you working on?

[@maniawan6789]

variable frequency drive means motor drive

[@AmericanWireman]

Did you pass

[@dhavalvartak6116]

Nice video

[@sarwarhossain2964]

great video

[@tauqeer2k]

Very nice Video...subscribed

[@dukewp5481]

Hello Red River Electricians

[@thedon8594]

Here's an engineering video that like many have not learned about sound bias. I CANT HEAR IT W/O headphones or amp. The bias is so low it has ruined your video.

[@sanjeevrana8317]

Great video