Howtosignalprocessing
- Why are there only odd harmonics?
- How non-linear device can generate harmonics?
- Why even harmonics are absent in electrical systems?
- Why non-linear distortion is called harmonic distortion?
Why are there only odd harmonics?
Most electrical loads (except half-wave rectifiers) produce symmetrical current waveforms, which means that the positive half of the waveform looks like a mirror image of the negative half. This results in only odd harmonic values being present.
How non-linear device can generate harmonics?
In power systems, a harmonic is a current or voltage that is a multiple of the fundamental frequency of the system. Non-linear devices or loads such as saturated magnetic devices, discharge lighting, and rectifiers produce these harmonics through their actions.
Why even harmonics are absent in electrical systems?
The even harmonics do not normally exist in power system due to symmetry between the positive- and negative- halves of a cycle. Further, if the waveforms of the three phases are symmetrical, the harmonic multiples of three are suppressed by delta (Δ) connection of transformers and motors as described below.
Why non-linear distortion is called harmonic distortion?
With non-linear distortion the application of a sinusoidal input voltage results in a periodic output waveform that is non-sinusoidal. Fourier analysis shows that spurious harmonics are present, the result being known as harmonic distortion.
