Problems with Harmonics - LNK417

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Hi,

I design a LED-Driver for Streetlightnig. But we have massiv problems with harmonic currents @ 5,7,9,11 orders.

Effency of the driver is ~ 91,5% (very nice performance). Is it possible that we do a big fail with the filters or "DC" Caps? Powerfactor isnt stabil but with full Load we get an PF of 97%

Please refer to the atteched PDF.

Transformer:
1207µH prim
2x 28T prim (Series), 2x 14T Sec(Parall), 9T Bias
Core: PC44; PQ3230
The same configuration like the RDR-290 Transofrmer

System Parameters:
30W-Outputpower, 230V 50Hz AC Input, 0,88A @32-36V Output

2.
I want use the Transformer and the System for a 50W and 75W Powersupply... only change the LNK-IC. Is That possible?

Thank you for help.

*** 09.01.15
I add a picture from my mesured values ... Order 9 and 11 are the biggest problem.

첨부 파일Size
OptiX2_LED-Treiber.pdf52.73 KB
OptiX Harmonics.PNG39.07 KB

The Link-Switch-PH spreadsheet has a harmonic calculation at the bottom of the spreadsheet. Use this to obtain your desired objective. To reduce harmonic content, you can play by reducing KP and/or increasing VOR on your transformer design.

Using the same transformer for 3 different power might be possible but of course have tradeoffs as you cannot get the best performance. You can also use the spreadsheet to do this.

Thank you for fast answer.

Yes I think I have some problems with our transformer.
PIXI calculate me Primary Inductance: 2900µH ... and my transformer have ~ 1205µH

Can i edit the Prim. Windings manual? I cant setup the "real" transformer in my spreadsheet.

Thats really hard ... we buyed 500pcs from this transformer and rebuild the RDR-290 with 35W Power! Is that desing with this transformer rescueable?

Thank you :(

TitleSize
LinkSwitch-PH Design1.pdf71.35 KB

Thank you for fast answer.

Yes I think I have some problems with our transformer.
PIXI calculate me Primary Inductance: 2900µH ... and my transformer have ~ 1205µH

Can i edit the Prim. Windings manual? I cant setup the "real" transformer in my spreadsheet.

Thats really hard ... we buyed 500pcs from this transformer and rebuild the RDR-290 with 35W Power! Is that desing with this transformer rescueable?

Thank you :(

TitleSize
LinkSwitch-PH Design1.pdf71.35 KB

VOR and NS are user inputs. If you fixed VOR then change NS (or vice versa) NP will change accordingly.