4/25/2008 2:10 PM | |
Posts: 148 Rating:
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What is product type and code of same?? |
4/26/2008 5:09 AM | |
Joined: 9/27/2006 Last visit: 8/18/2024 Posts: 12279 Rating:
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Hello tambe; First here is how the Siemens drive portal explains the use of a harmonic filter (with the Sinamics family): As network-friendly as the 12-pulse technologyThe Sinamics G150 converters are all designed in 6-pulse technology. The VDEW regulations for power stations demand harmonic values as they are normally only achievable with 12-pulse technology. To meet this strict standard, the Sinamics G150 converters are preceded by line harmonics filters. These line harmonics filters then reduce the low-frequency mains feedback to the level of a 12-pulse converter and even below these values. They considerably reduce the 5th and 7th current harmonics in particular. The mains current consumed by the line harmonics filter is very close to the sinusoidal shape and therefore fully meets the requirements of the VDEW. In comparison with conventional 12-pulse feeds, no triple-wound transformer with 30° offset secondary windings is necessary in concepts with 6-pulse converters plus line harmonics filters. Because of the low current root mean square value, smaller cross sections of the mains supply cable are possible and the losses in the transformer are lower. Because no second rectifier is necessary the entire system is more compact on the whole. Line harmonics filters are installed as independent components in a robust housing between Sinamics G150 and the low voltage distributor. They are assembled without a fan and operate with internal convection cooling. This eliminates the necessity for both an auxiliary power supply and all maintenance.Sinamics G150 which are already in operation can also be retrofitted quickly and simply with a line harmonics filter. By pre-circuiting a line harmonics filter, the Sinamics G150s are independent of the network operator's requirements - the ideal solution for all low-voltage drive tasks of high power which require no feedback - whether in energy generation or elsewhere. There are a few models of these line harmonic filters on the Mall, under the generic part number: 6SL3000-0Jx3x-xAA0 Sinamics line Harmonics filter There is no mention of lne harmonic filters on the Micromaster line, possibly because the directives that the filters are used on are newer than the line of drives. You would have to discuss with a Siemens Drives specialist if those older models can be retrofitted with such a filter, and if they would benefit from them. On the other hand in the manuals of the Micromaster 440 they discuss what Siemens calls an Active Front End associated to a Clean power Filter in similar terms as the Active harmonic Filter of the Sinamics dirive. This is what is said on the Active Front End: An ACTIVE FRONT END (AFE) is another option available to control regenerative voltage. With this option the diodes in the converter bridge are replaced with IGBT modules and a Clean Power Filter. The IGBT, controlled by control logic, operates in both motoring and regenerating modes And here is mentionned their use: Harmonics are created by electronic circuits, such as the nonlinear loads of adjustable speed drives. Harmonics can cause problems to connected loads. The base frequency is said to be the fundamental frequency or first harmonic. Additional harmonics that are superimposed on the fundamental frequency are usually whole number multiples of the first harmonic. The fifth harmonic of a 60 Hz power supply, for example, is 300 Hz (60 x 5). A distinct advantage of Siemens MASTERDRIVES equipped with AFE and a Clean Power Filter is they are optimally harmonized with each other to eliminate harmonics and provide a clean power supply. In addition, the Siemens AFE allows for capacitive KVAR production which effectively compensates for other inductive loads in an industrial plant. This helps reduce the overall utility bill. |
1/23/2020 2:44 PM | |
Posts: 10 Rating:
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There is also a decent blog covering the subject at : https://activeharmonicfilter.net/ |
Last edited by: OLundberg at: 01/27/2020 09:53:00 |
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1/27/2020 9:40 AM | |
Posts: 10 Rating:
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True, always start with chokes to reduce harmonics. By far the cheapest first step. |
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