Low Harmonics Technology

Low Harmonics Design

The unique low-harmonics design sets the SED2 VFD Drive apart from its competitors. While other drive manufacturers use filtering devices to control harmonics, which add cost and complication, the SED2 VFD Drive design provides a new method of reducing the input line harmonic currents without the addition of extra components. The SED2 drive uses lowered DC link capacitance to minimize harmonics in a cost-effective manner.

Low Harmonics Design

Current Wave Form of Typical 6 Pulse Drive vs. the SED2 VFD

At the input terminal of a PWM 6 Pulse Drive, THD can be in excess of 120% without any filtering. The SED2 produces only 29%. 

Total Harmonic Distortion Reduction Comparison

In tests between a typical 6 pulse PWM drive with and without line reactors and DC link chokes versus the SED2 VFD, the Siemens Easy Drive demonstrates superior harmonic performance. In typical HVAC applications, the SED2 VFD can reduce harmonics by up to 25% more than other VFDs even with line reactors and DC link chokes.

Total Harmonic Distortion Reduction Comparison


Harmonee - Harmonics Calculator Tool

Harmonee - Harmonics Calculator Tool

Easy-to-install and use, Harmonee is a powerful harmonics analysis tool. Just enter the job-site specific data and let Harmonee create harmonics analysis data for that facility, including:

  • Full harmonics spectrum of every harmonic order and what their respective values are

  • Compares expected results with worldwide harmonics standards including IEEE519-1992

  • Gives the user the ability to compare harmonics generated by other comparable 6 pulse drives versus the incredibly low harmonics generated by our SED2 VFDs

  • Compares conventional drives with and without the use of filtering devices to reduce harmonics such as line reactors


Harmonee Tutorial

A Harmonee Tutorial has been written to walk you through, step-by-step using the new tool. The Tutorial will help you interpret your data and will show you all of Harmonee's capabilities!


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