Shreem Capacitor Pvt.Ltd.-Harmonic Study & Harmonic Filter

Capacitors,Power Quality, Harmonic filters,Powerquality, Solutions, APFC.

Harmonic Study & Harmonic Filter-The Concept

Harmonic Analysis
Industiral customers haall limit the harmonic loever to met the guidline of IEEE-STD 519; This will make the evaluation of power factor/harmonic filters even more essential. The first stp in a harmonic study is to carry out system analysis in the Power System to know following paramerts & to determine filter.
Power System line diagram Fault Level Transformer rating Load details- Motors, drivers etc. Harmonic details - THD, individual harmonic level. Energy consumption.

What is Harmonic Filter?
suitable series reactor shall be connected in series with capacitor to avoid resonance. A filter may be installed for one load or many loads . Its design requires datail study of the power circuit.filter sizing depends on the harmonic spectrum & fault level of the load. the types of L.V. filters are indicated below:


1) Detuned Filter:
The idea is to trap the harmonic currents in L/C circuits tuned to the harmonic orders requiring filters. A filter comproses a seres of stages each corresponding to harmonic orders. This reactor combination is designed to have a resonant frequency 131 Hz/189Hz. In this case 5th , 7th , 11th harmonic currents will be absorbed

2) Partial Tuned Filter:
In this system reactor/ capacitor combination is designed in such a way that system resonance are acoided and approzimately 40% of the 5th harmonic current can be absorbed.

3) Tuned Harmonic Filter:
Tuned filter consist of series reactor & capacitor tuned to the particular given frequency producing zero impedance path to harmonic current. Almost 80 to 90 %of harmonic current can be brought down in the supply network. However it can , be installed only across few types of loads.

4) Active Harmonic Filter:
The active hamonic filter concept uses power electronics to introduce current components, which cancel the harmonic components of the non-linear loads. It actively eliminates 100% hamonic distortion & reacts instantly to verifying load conditions. It also balances three phase loads. Today the widespread use of 1GBT components and the availability of new DSP components will give bright future for active filters . This type of filter will be launched by us soon.