Infolliance take up projects in Harmonics involving harmonic audit, recommendation and installation of filters. The products and services in this area covers the following:

Harmonic Audit
Recommendation of Filter System
Supply & commissioning of Filter System

Modern industries requires automation of their operation enabling them to produce quality products and also for mass production. The conventional systems are being replaced by modern Power Electronic systems, bringing a variety of advantages to the users. Classic examples are D.C. & AC Drives, UPS, soft starters, etc. Since the thyristor converter technology is rapidly gaining ground in the modern industrial plants, the power supply systems are contaminated as the ideal sinusoidal current and voltage waveforms are getting distorted. This in turn is affecting the performance of the equipment in the electrical network, especially the Power Factor correction capacitors.

I. Sources of Harmonics:

Non linear loads as mentioned below are the main sources of Harmonics in the electrical network:

1. AC Variable Frequency Drives
2. D.C. Thyristor Converter Drives
3. Induction Furnaces & Thyristor Controlled Furnaces
4. Rectifiers
5. UPS & SMPS (Used in Computers & Automation Systems)
6. Electronic Ballast

II. Effects of Harmoncs:

Increased heating due to iron and copper losses in machines at higher frequencies.
Harmonic current pairs such as 5th and 7th have potential to create mechanical oscillation in Motor-Load or Turbine-Generator combination. This in turn may produce oscillating torque. Also, these harmonic currents generate heat in the electrical network and in motor windings in both stator and rotor.
Harmonics create increased level of noise and harmonic current causes additional copper and stray flux losses. Harmonic voltages cause increase in iron losses.
Cables may have voltage stress and corona leading insulation failure and also higher, skin effect.
Failure of Power Factor improvement capacitors and Poor Power Factor
Power electronic equipment are susceptible to mis-operation caused by harmonic distortion (shift in voltage crossing).
The accuracy of Meters and instruments can be affected with high harmonic distortions and may show erratic readings.
Harmonic currents in switch gear increase heating and thus excess losses. It can also affect operation of relays.
Energy Losses

III. Solution to Harmonics:

Distortion in the voltage and current wave form is not desirable in the electrical network because of their adverse impact on the connected equipment. It is therefore, prudent to install tuned harmonic filters close to the loads generating harmonic currents so that the harmonic currents are filtered at the source and relieving the network from the evil effects of harmonics. A Harmonic Filter system basically consists of Capacitor bank connected in delta and a series reactor. These will be housed in a suitable panel along with necessary switch gear and meters. The filter injects required kVAr to the network and improve the Power Factor till the tuned frequency and beyond the tuned harmonic frequency, it will be inductive and thus prevent amplification of harmonic currents.

IV. The Benefits by installing Harmonic Filter System:

Reduction in Energy Losses & reduced energy bill
Reduction in unexpected demand of energy due to harmonic currents
Less equipment failure and maintenance
Increase in available capacity
Increase in life of electrical equipment, measuring instruments and cables
Lower work interruption and downtime
Lower maintenance costs
Improved system efficiency
Lower maintenance
Improved safety
Improved system power factor

For further details please download Presentation & Catalogue: Downloads


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