TORONTO, ONTARIO--(Marketwired - Sept. 22, 2015) - A new whitepaper from harmonics solutions provider MIRUS International shows that a properly designed passive harmonic filter has significantly greater effectiveness in treating Variable Frequency Drive (VFD) harmonics than using an Active Front End (AFE) Drive. The study shows that despite the fact that a number of manufacturers tout AFE Drives as the superior solution, the passive approach has many obvious benefits.

"Active Front End (AFE) Drive manufacturers claim that their technology provides the best solution for the treatment of harmonics associated with variable frequency drives," says Tony Hoevenaars, P.Eng., President and CEO of MIRUS International and author of the whitepaper. "They are quick to point out the benefits over standard 6-pulse VFDs equipped with diode bridge rectifiers, but what they won't tell you is that current harmonics are much higher when measured above the 50th, and that serious problems can result from introducing these higher frequency harmonics."

The paper compares the two technologies in detail, and outlines a number of key reasons why AFEs are not the best solution for a low harmonic VFD. While it is true that they reduce the low frequency harmonics introduced by the VFD, they do so with negative consequences including:

• high levels of high-frequency harmonics
• an input-passive LCL filter that performs poorly and can resonate with the power system
• higher levels of common-mode ground leakage current
• much higher losses
• increased complexity, which reduces reliability
• significantly higher costs

The paper explains that combining a Lineator AUHF Wide Spectrum Filter with a simple 6-pulse VFD is a much more efficient solution with the following advantages:

• no high frequency harmonics
• compatibility with the power system (including resistance to resonance and low capacitive reactance for compatibility with generators)
• higher efficiencies
• improved reliability
• lower installation and operating costs

"The combination meets the most severe requirements for harmonic reduction, without the negative consequences of AFE technology," says Hoevenaars. "MIRUS has had tremendous success with our proven Lineator AUHF technology."

For more details about the benefits and drawbacks outlined here, download the full whitepaper.

About MIRUS International

MIRUS International Inc. supplies specialized power quality products that reduce harmonic problems and save energy in electrical power distribution systems worldwide. They have produced many patented designs useful in addressing problems associated with harmonic generating non-linear loads such as personal computers, telecom equipment, broadcasting equipment and Variable Frequency Drives (VFDs). Their newest generation of Lineator Advanced Universal Harmonic Filter (AUHF) is the solution of choice for major VFD manufacturers and is specified by consulting engineers worldwide.

Tony Hoevenaars, President & CEO

Prior to joining MIRUS in 1996, Tony was the chief facilities electrical engineer at an IBM manufacturing facility in Toronto, where he gained experience in solving power quality related problems, particularly in the area of harmonics. Tony is a professional engineer, member of IEEE and has published numerous peer reviewed and white papers on power quality.