Harmonics overview

October 12th, 2009 | Posted in Power quality
Tags: , , , ,

Why problem?    3 types of solutions!      How to make a choice ?     Any software tools ?

Typical distorted current waveforms

Typical distorted current waveforms

The wide spread use of power electronic devices in power networks is due to their multiple functions: compensation, protection, adaptation and transformation of the electric energy. However, because of their switching components, power electronic converters generate current and voltage which may cause measurements, stability and control problems.

To avoid the harmonic distortion, it is necessary to equip the installation with filtering systems.

There are 3 types of filters: , and hybrid.

  • The represent a LC circuit tuned to a harmonic order close to the order to be eliminated. Several parallel-connected branches of filters can be used if a significant reduction in the distortion of a number of harmonic orders is required.
  • The represent power electronics devices, which generate and inject drawn in an opposite phase such that the line current Is remains sinusoidal.
  • The hybrid filters are a combination from and .

Before to reduce the distortion, the installation of meter devices is recommended. This is the first step in gaining control over harmonic pollution!

Measurements allow to obtain an overall idea on distribution-network status and to choose the solution for the reducing of the distortion.

In industry, very often the capacitor banks are combined with harmonic filters, as they are highly sensitive to the harmonic disturbances.

At my knowledge, there is no tool or software that can be used for the choice of the harmonic filters, mainly measurements are used and individual solutions are proposed.

In contrary, several software exist for sizing the capacitor banks…. Like

Christian Petrov

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4 Comments to “Harmonics overview”

  1. jasmin says:

    can u give me information about compensation of harmonic using active harmonic conditioner(AHC)?

  2. ppmm says:

    what is harmonic, what is called harmonic exactly? ( is it the same as we have in music if yes, go on >> )
    can we say in AC, zero crossing of current ( or voltage ) can cause harmonics ( some repeated waves with different frequencies?
    if yes, so what is harmonic in DC which we don’t have any zero crossing!?
    I really want to know the concept of harmonic ( or harmonics!! or even harmony, which one ? ) in Electrical Engineering.

    I am electrical engineer but i still have problem in this ( and many more … )

    Thanks

  3. nadia says:

    hello..i really need your help..i’m doing my project..n if can i want to know how to design circuit of active power filter that design to eliminates harmonics.The inverter is power switches which is IGBT.I also dont know how to connect and design the position and control the IGBT..Thank you..I really need your help as soon as possible

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