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

Calculate the gross torque developed for a flux, Q. A four-pole, dc seriesm...

Q. A four-pole, dc seriesmotor has a lap-connected, two-layer armature winding with a total of 400 conductors. Calculate the gross torque developed for a flux per pole of 0.02 Wb a

Ionic bonding, Ionic Bonding Instance: NaCl. Na (Z = 11) gives u...

Ionic Bonding Instance: NaCl. Na (Z = 11) gives up the outermost shell electron of it to Cl (Z=17) atom, so the crystal is build up of ions with the electronic structure

Process , Process The rectangle symbol  is used to represent  the pro...

Process The rectangle symbol  is used to represent  the process  operations as shown below.   MOV A, B

Low voltage at transformers, Low Voltage at Transformers While the vo...

Low Voltage at Transformers While the voltage applied to induction motor varies from the rated voltage, its performance is affected. Against permissible voltage variation of

Explain lda and daa instructions, Explain LDA, STA and DAA instructions ...

Explain LDA, STA and DAA instructions LDA copies the data byte into accumulator from the memory location particular by the 16-bit address. STA copies the data byte from the acc

What do you mean by nibble, Q. What do you mean by Nibble? The nibble i...

Q. What do you mean by Nibble? The nibble is a collection of bits on a 4-bit boundary. It would not be a particularly interesting data structure except for two items BCD (binar

Different types of dc generation, Q.   What are the different types of dc g...

Q.   What are the different types of dc generation according to the ways in which fields are excited. Show the connection diagram of each type. Ans. Types of D.C.

Forces and torques in magnetic-field systems, Q. Forces and torques in magn...

Q. Forces and torques in magnetic-field systems? We mentioned earlier that the greater ease of storing energy in magnetic fields largely accounts for the common use of electrom

Discuss dos function call with one example, Discuss DOS function call with ...

Discuss DOS function call with one example. DOS function call: So as to use DOS function calls, always place the function number in register AH and load all other pertinent

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