Harmonics: Enemy of true sinusoidal wave

Harmonics: Enemy of true sinusoidal wave

In a perfect power system, the voltage supplied to user, and the supplied load current are exactly sine waves. In practice, notwithstanding, conditions are never perfect, so these waveform are sometimes distorted. This deviation from ideal sinusoidal waveform is  expressed as harmonic distortion of voltage and current waveform.

Harmonic signals are integer multiple of fundamental frequency of original signal. for example a signal of fundamental frequency 50 Hz will have its harmonic components of 3rd and fifth order with frequencies of 150 hz and 250 hz respectively.

Bad Effects of  Harmonics:

• Effects on the power system itself 

Causes over heating and thermal loss of life great challenge for motors and transformers.

•  Effects on consumer load 

Causes thyristor firing errors in inverter and SVC installations. performance of consumer devices and machines is adversely affected.

• Effects on communication circuits 

Distortion in communication signals may result in distorted demodulated signal.

•  Effects on revenue billing 

Harmonic voltage distortion can impact charging by bringing mistake into kilowatt  hour metering frameworks that depend upon correct acumen of the voltage zero. Also, of  course harmonic current wholes with central current requested by facility loads to  straightforwardly expand net billable kilowatt request and kilowatt hour utilization charges