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RHF-Active
Highly efficient active harmonic filter
The RHF-Active uses Silicon Carbide (SiC – MOSFET) technology, which offers significant benefits in performance and efficiency.
The efficiency of a SiC harmonic filter is >98% and therefore produce about 57% less heat than comparable solutions based on IGBT technology. Looking at the RHF-Active as a Harmonic solution for drives, the system efficiency is >99.3%. For drives <200kW this is even more efficient than RHF two-stage passive harmonic filter.
The efficiency of a 3-Level IGBT based Harmonic filter is >97% and therefore produce 41% less heat, than comparable solutions based on 2-Level IGBT Technology. Looking at the RHF-Active as a harmonic solution for drives, the system efficiency is >99%.
The RHF-Active may be used for pf correction, unbalance compensation, harmonic mitigation or altogether. It reduces the harmonic current distortion of non-linear loads and sources to any required THDi. This is necessary to reach various standards and recommendations, such as IEEE 519-2014.
A high switching frequency allows for efficient and accurate compensation of high order harmonics up to 61st. Due to its unique circuit, the RHF-Active is extremely efficient which allows for a very compact design. All RHF-Active can be used as 3P4W or 3P3W for 380-415V systems (further voltage levels coming soon!). Unlimited current possibilities due to open end in parallel setup!
The working principle of an active REVCON Harmonic Filter RHF-Active is completely different from any other harmonic solution. Instead of working as a line filter with tuned passive filter circuits, the active solution is connected in parallel and injects harmonics. These injected harmonics are of inversed polarity and therefore eliminate the harmonics taken from the supply.
|
Application |
RHF-8P <8% THDi |
RHF-5P <5% THDi |
RHF-Hybrid ~1% THDi |
Active <5% THDi |
|
Vaiable Frequency Drives – VFD |
Yes |
Yes |
Yes |
Yes |
|
Water and wastewater treatment |
Yes |
Yes |
Yes |
Yes |
|
HVAC |
Yes |
Yes |
Yes |
Yes |
|
Pumps and Fans (VFD) |
Yes |
Yes |
Yes |
Yes |
|
Industrial/ Factory Process (VFD) |
Yes |
Yes |
Yes |
Yes |
|
DC charger |
Yes* |
Yes* |
Yes |
Yes |
|
Buildings |
Yes |
Yes |
Yes |
Yes |
|
Data Center (power supply) |
No |
No |
Yes |
Yes |
|
IEEE 519-2014 requirement |
Yes* |
Yes |
Yes |
Yes |
|
Marine |
Yes |
Yes |
No |
No |
|
IEEE 519-2014 specified application |
Yes |
Yes |
Yes |
Yes |
|
Electronically comutated / EC Motor |
No |
No |
Yes |
Yes |
|
Non symetrical Load |
No |
No |
No |
Yes |
|
Symetrical load multiple VFD |
Yes |
Yes |
Yes |
Yes |
|
Symetrical load multiple equimpment |
No |
No |
No |
Yes |
|
Displacement factor correction („pf“) |
No |
No |
No |
Yes |
|
Unbalance compensation |
No |
No |
No |
Yes |
Ideally all loads and sources have a pure sinusoidal current waveform. But unfortunately the true waveform of most equipment is very different. Nonlinear loads like for example the diode input bridge of a 6 pulse drive, are causing a distortion of the mains voltage. This distortion typically evaluated by the Total Harmonic distortion THD, evaluates frequencies from the 2nd up to the 40th harmonic. In a 50Hz Network this is the area between 100Hz and 2kHz.
The impact of the voltage distortion is diverse, and the most typical effect is overheat of transformer and PFC applications (Capacitor banks). Underestimated impacts of harmonic distortion is the significantly reduced lifetime expectation of electrical and mechanical equipment.
The Revcon Harmonic Filter (RHF) avoids the harmonic distortion of nonlinear loads and sources. The filter is not tuned to a specific frequency, but works like a bandwidth filter, reducing all frequencies up to the 50th harmonic. The RHF filter reduces the Total Harmonic Distortion of the current (THDi) to a level significantly below 5%. This is necessary to reach various standards, for e.g. IEEE 519-2014, who are getting more and more common.
Harmonic Distortion of Drives Part 1: Issues
Harmonic Distortion of Drives Part 2: Solutions
