REPORT ON HARMONICS AND ITS SOURCESINTRODUCTION: There are many electrical appliances they have non-functional features, and when applied to power distribution circuits will build and produce nonlinear currents and voltages. Because from time to time nonlinearities can be better analyzed using Fourier Switch, these non-line currents and mobility they have often been referred to as 'harmonious'. Among devices that can make nonlinear currents are transformers and induction motors (due to magnetic core saturation) and energy electronic meetings (for the most part, occasionally Impedance changes in categories). DC Adjustable Speed Drive, which uses six heartbeats converter or some modification of it, has always been has been popular in the industrial area for many years and many application developers are familiar with nonlinear currents and voltages that converter can produce. These conditions have been studied some time ago. Because of the interaction of these non-energy channels grid impedance, offline cables will be made. The combination of this offline has led to problems due to the power system resonance, or heating or energy efficiency parts of the system. Reportedly burned transformers, capacitors, reactors, generators, and motors. Circuit malfunction is reported waves. Steps have been taken to limit this currents and voltages in some more equilibrium of these parts. These steps led to the implementation of standards that recommend limits harmonic currents and slopes at Point of Common Concentration (PCC). While many papers they were dedicated to analysing the conversion circuit to to determine harmonic currents, is far from over it is easy to measure these currents and analyse them with them on Fourier change. This paper will show examples of how you can do this and show wave forms for six pulse converters, both controlled once uncontrolled, and VSC.