The Effects of Harmonics:

Harmonics do not only affect the waveforms of the loads but also cause negative effects on the elements of the power system. They can cause additional losses in motors, generators, transformers, capacitors, and they can cause damage or failure of these elements. Due to the formation of oscillations in synchronous and asynchronous motors, overheating and additional noises are formed.
Due to the additional losses and increased voltage drop, the efficiency in power generation, transmission and distribution will be reduced. In addition, due to the harmonics, there will be different frequency components outside the basic frequency in the system, so the probability of occurrence of resonance event will increase. High current and voltages that may occur as a result of resonance will seriously damage the elements and loads connected to the grid.
The capacitors in the compensation groups designed for the basic frequency of the network are damaged by pulling over current due to their low resistance in the harmonic frequencies. Precision electronic components such as microprocessors work incorrectly, causing malfunctions in the control systems. Noise and noise are seen in audio and video communication devices.
They have a direct effect on human health by causing vibration in lighting elements and monitors. It is also effective in the increase of iron losses in the fluorescent lamps with the noise that the ear can hear. Harmonics also cause malfunctions of protective equipment and shorten the life of the devices.
Several standards have been established to reduce these harmful effects. Limiting the harmonics to the standards is extremely important for reducing the additional losses in the system, working at the full capacity of the devices used, and for eliminating the stresses and faults that may occur.