The role of the filter in the power transformation and distribution system has a filter device, its role is mainly to filter out harmonics, because the power grid is theoretically a three-phase sine wave, 50 Hertz per second frequency, but in actual use, its sine wave will change, and electrical equipment on the grid requirements are relatively high, it is difficult to use.
For example, three-phase rectifier equipment, thyristors, controllable tubes and so on, they all have certain standards, the general supply network harmonic is divided into one, two...... Maximum can be more than ten times, which shows that the quality of power supply is very poor, now most of the use of resistance capacitance absorption device, of which, resistance: inductance, current limiting effect, capacitance: capacitance, filter, add up is the resistance capacitance absorption device, it can also play a power factor compensation role, but to be reasonably matched, and there are a variety of connections, must be done under the guidance of professionals,
The capacitor is to filter out high-frequency clutter, and the coil is to stabilize the current, in a word, guaranteeing clean voltage and stable power