What is harmonic control? Will harmonics cause harm to electrical energy?

The quality of power quality directly affects the quality of industrial products. There are three standards for evaluating power quality. The first is voltage, which includes voltage fluctuation, voltage offset, voltage flicker, etc.; second is frequency fluctuation; and finally is the voltage waveform quality, that is, the symmetry of the three-phase voltage waveform and the distortion rate of the sine wave. , that is, the proportion of harmonics. Our country has clear standards and specificati