Total harmonic distortion, Electrical Engineering

Assignment Help:

Q. Explain the term total harmonic distortion. Describes the functionary of a total harmonic distortion analyzer.

Total Harmonic Distortion: Nonlinear behaviors of circuit elements introduce harmonics in the output waveform and the resultant distortion. A nonlinear system produces harmonics of an input sine wave, the harmonics consisting of sine waves with frequencies which are multiples of the fundamental of the input signal. Total harmonic distortion is measured in terms of the harmonic content of the wave, as given by equation.

     A measure of distortion represented by a particular harmonic is simply the ratio of amplitude of harmonic to that of the fundamental harmonic distortion is then represented.

 Harmonic Distortion Analyzer: a harmonic distortion analyzer which is used to measure THD. The signal source has very low distortion and this can be checked by reading its output distortion by connecting directly into the analyzer. The signal from the source is fed into the amplifier under test. The generates harmonics and the original frequency (fundamental). The fundamental frequency is removed by the notch filter.

        In the manual system of the switch SW is first placed imposition and the total content of fundamental and harmonics is measured. Then the switch is moved to position to measure just the harmonics. The value of THD is then fond from equation.

 The meter can be calibrated by putting the switch in position and adjusting the reading for full scale deflection. Wight the switch in position the meter reading is now proportional to THD.

  Shows an alternative arrangement, where the values of are read simultaneously and their ratio calculated and displayed as THD on the indicator. For good accuracy the notch filter must have excellent rejection and high pass characteristics. It should attenuate the fundamental by 100 db or more and the harmonics by less than 1dB. The filter also needs to be tuned accurately to the fundamental of the signal source. This is difficult to achieve manually and most distortion analyzer do this automatically. A common from of notch filter is Wien Bridge. The balances at one frequency only and at this frequency the output voltage at the frequency only and at this frequency the output voltage at the bridge null detector is minimum.


Related Discussions:- Total harmonic distortion

Conducting material, #question.classification of conducting material.

#question.classification of conducting material.

Fermi dirac level, Fermi Dirac level: Sol. The Fermi level is simply...

Fermi Dirac level: Sol. The Fermi level is simply a reference energy level. It is the energy level at which the probability of finding an electron n energy unit above it in

Survey methods and analysis - power supply, Survey Methods and Analysis - P...

Survey Methods and Analysis - Power Supply There are two major methods of gathering information from customers: qualitative and quantitative.  Quantitative Rese

Modify the jk flip-flop to operate like the t flip-flop, Q. A JK flip-flop ...

Q. A JK flip-flop is shown in Figure (a). (a) Modify it to operate like the D flip-flop of Figure (b). (b) Modify the JK flip-flop to operate like the T flip-flop of Figure (

Active-mode pnp transistors in circuits, Active-mode PNP transistors in cir...

Active-mode PNP transistors in circuits: In the figure, the arrows showing current point in the direction of conventional current - the flow of electrons is in the opposite di

Explain dielectric constant, Explain Dielectric constant. Dielectric co...

Explain Dielectric constant. Dielectric constant: This is also termed as 'Permittivity'. All insulating material possesses an electrical capacitance. Such capacitance of unit d

Chemistry, explain why entropy of a gas increases with volume and tempeart...

explain why entropy of a gas increases with volume and tempearture

Boost converter - power supplies , Boost Converter The boost  convert...

Boost Converter The boost  converter has its  output  voltage always  greater than input  voltage like  a buck  converter boost  converter has two  modes.

Emf, what is emf

what is emf

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd