1.2 Harmonic in Utility power supply due to rectification.
Methods for limitation and elimination of disturbances and harmonic pollution in the power system have been widely explored. This problem rapidly build up with the increasing amount of electronic equipment (computers, radio set, printers, TV sets, motor control etc.). These nonlinear load equipment are sources of current harmonics in the input lines which produce increase of reactive power and power losses in transmission lines. The harmonics also cause electromagnetic interference (EMI) and, sometimes, dangerous resonances. They have negative influence on the control and automatic equipment, protection systems, and other electrical loads, resulting in reduced reliability and availability. Moreover, nonlinear loads and non-sinusoidal currents produce non-sinusoidal voltage drops across the network impedances, so that non-sinusoidal voltage appears at several points of the mains. It brings out overheating of line, transformers and generators due to the iron losses.