the total harmonic distortion, or thd, of a signal is a measurement of the harmonic distortion present and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency. thd is used to characterize the linearity of audio systems and the power quality of electric power systems. distortion factor is a closely related term, sometimes used as a synonym. in audio systems, lower thd means the components in a loudspeaker, amplifier or microphone or other equipment produce a more accurate reproduction by reducing harmonics added by electronics and audio media. in radiocommunications, lower thd means the pure signal emission without causing interferences to other electronic devices. moreover, the problem of distorted and not ecoâfriendly radioâemissions appear to be also very important in the context of spectrum sharing and spectrum sensing.iaroslav blagouchine and eric moreau. analytic method for the computation of the total harmonic distortion by the cauchy method of residues. ieee transactions on communications, vol. 59, no. 9, pp. 2478â2491, september 2011. in power systems, lower thd means reduction in peak currents, heating, emissions, and core loss in motors.total harmonic distortion and effects in electrical power systems - associated power technologies ==definitions and examples== to understand a system with an input and an output, such as an audio amplifier, we start with an ideal system where the transfer function is linear and time-invariant. when a signal passes through a non-ideal, non-linear device, additional content is added at the harmonics of the original frequencies. thd is a measurement of the extent of that distortion. when the main performance criterion is the â³purityâ³ of the original sine wave (in other words, the contribution of the original frequency with respect to its harmonics), the measurement is most commonly defined as the ratio of the rms amplitude of a set of higher harmonic frequencies to the rms amplitude of the first harmonic, or fundamental, frequencyon the definition of total harmonic distortion and its effect on measurement interpretation, doron shmilovitz{{cite book | last = slone | first = g. randy | title = the audiophile's project sourcebook | publisher = mcgraw-hill/tab electronics | year = 2001 | isbn = 0-07-137929-0 | page = 10 | quote = this is the ratio, usually expressed in percent, of the summation of the root mean square (rms) voltage values for all harmonics present in the output of an aud
Electrical_parameters