Harmonic distortions in electrical circuits are a concern because they can cause significant damage to the equipment they are connected to. Harmonics are unwanted frequencies that are higher than the fundamental frequency of the power source. They are created by nonlinear loads, such as rectifiers and capacitors. Passive harmonic filters are an important part of power system design. They are used to prevent harmonic distortion, which is a problem that can affect the operation of equipment. They can be used to mitigate these effects by converting harmonics into other forms of energy (such as heat) or by blocking them from reaching their intended target. Types of Harmonic Filters There are three types of passive harmonic filters: series inductors, shunt capacitors, and shunt reactors. Series inductors require a minimum amount of current before they begin to conduct harmonics; shunt capacitors allow harmonics to pass through while blocking DC voltage; shunt reactors convert ...