Frequently Asked Questions: Harmonics

What Causes Harmonics?

Nonlinear loads are the primary causes of harmonics in an electrical system. Non-linear loads draw short bursts of current, which creates a situation where current is not proportional to the voltage. These loads create harmonic distortion that can have adverse effects on your equipment. Nonlinear loads are most associated with modern electrical equipment, such as:…

What Are The Effects of Harmonics?

A power system’s ability to perform at optimal levels is compromised when harmonic distortion enters the system. It creates inefficiencies in equipment operations due to the increased need for power consumption. The increase of overall current required creates higher installation and utility costs, heating, and decreasing profitability. Power system problems that can occur without a… Read more »

What Is Harmonics In An Electrical System?

Harmonics in its simplest form is quite simply distortion, which can negatively impact an electrical system. From a technical perspective, harmonics can be best described as the shape or characteristics of a voltage or current waveform relative to its fundamental frequency. But what does that mean? Well, the ideal power source for all power systems… Read more »

What Is A Harmonic Filter?

A harmonic filter is a device that reduces, or mitigates, harmonics to tolerable levels. They are commonly used to lower harmonic distortion to the levels detailed in IEEE 519, the IEEE Recommended Practice and Requirements for Harmonic Control in Electrical Power Systems.  Harmonic filters solve problems in markets such as Oil & Gas, HVAC, Water/Wastewater… Read more »

What Are Passive Harmonic Filters?

Passive harmonic filters are series filters (which means that current goes through the filter) that are used to reduce, or mitigate, harmonics to tolerable levels as defined by IEEE-519. Passive filters use the following items to ‘filter’ (or clean) the current wave: Input reactor Output reactor Shunt reactor Capacitor Passive filters have many advantages over… Read more »

What Are Active Harmonic Filters?

What are active harmonic filters? Active harmonic filters are parallel filters (which means the current doesn’t go through the filter) that are used to reduce, or mitigate, harmonics to tolerable levels as defined by IEEE-519.  Active filters use a set of transistors and capacitors to filter (or clean) the current wave by injecting inverse currents… Read more »

What Is IEEE-519?

IEEE-519 is a system guideline for setting limits on voltage and current distortion. The Institute of Electrical and Electronics Engineers (IEEE) is a non-profit professional association dedicated to advancing technological innovation related to electricity. IEEE is one of the leading standards-making organizations in the world, and its standards affect a wide range of industries including… Read more »

PDFs On IEEE-519

MTE has a variety of PDFs outlining information on IEEE-519: Solution profile on meeting IEEE-519 with a six-pulse VFD Whitepaper on Harmonic Mitigation in Variable Frequency Drives: 6-Pulse Drive with MTE Matrix AP Harmonic Filter vs. 18-Pulse Drive   Helping Textile Manufacturer Meet IEEE-519 Standards