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

Features of tariff policy, Features of tariff policy: For projects who...

Features of tariff policy: For projects whose tariff is determined by performance- based cost of service regulation, the advantages of decreased tariff after full depreciation

.#title.Simulation on Half wave rectifier using PSpice, How to plot output ...

How to plot output power Vs load resistor graph using PSpice softwaer for half wave rectifier circuit

In-depth technical competence, Professional engineers engage with a wide ra...

Professional engineers engage with a wide range of technically advanced and complex problem. So technical know-how is necessary to solve problems, advance existing technologies and

Working of bootstrap sweep circuit, analysis and detail working of bootstra...

analysis and detail working of bootstrap sweep circuit

Transmission and distribution, A three-phase transposed line is composed of...

A three-phase transposed line is composed of one conductor per phase with flat horizontal spacing of 11 m as shown in Figure 1(a). The conductors have a diameter of 3.625 cm and a

Working of simple air evaporative, With the help of neat sketch T-S diagram...

With the help of neat sketch T-S diagram illustrate the working of simple air evaporative cooling system used in air craft. With the help of neat diagram and T-S diagram iillust

Name the effects of electric current, Name the Effects of electric current ...

Name the Effects of electric current There are three Effects of electric current:- A) magnetic effect B) chemical effect C) heating effect

Define not gate - microprocessor, Define NOT Gate - Microprocessor? The...

Define NOT Gate - Microprocessor? The NOT GATE which is as well called an Inverter, is used to invert the logic state of a signal. The output Q is true while the input A is NOT

Illustrate how to replace the ht fuse, Illustrate how to replace the HT Fus...

Illustrate how to replace the HT Fuse on a 6-pole and 4-pole structure? Ans: a) Open switch on 6-pole or 4-pole. b) Connect the discharge rod between earth and conduc

Combinational logic circuit , Design a combinational logic circuit to conve...

Design a combinational logic circuit to convert XS3BCD code in to the  standard 8421 BCD code.

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