How to Calculate Harmonic measurements in an electrical network?

Harmonic voltages and currents in an electric power system are a result of non-linear electric loads.Harmonic frequencies in the power grid are a frequent cause of power.Total harmonic distortion, or THD is a common measurement of the level of harmonic distortion present in power systems.

The harmonic indicators can be measured: 1.By an expert present on the site for a limited period of time (one day), giving precise, but limited perception, 2.By instrumentation devices installed and operating for a significant period of time (at least one week) giving a reliable overview of the situation, 3. by devices permanently installed in the distribution network, allowing a follow-up of Power Quality.