Methods for limitation and elimination of disturbances and harmonic pollution in the power system have been widely investigated. This problem rapidly intensifies with the increasing amount of electronic equipment (computers, radio set, printers, TV sets etc.). This equipment, a nonlinear load, is a source of current harmonics, which produce increase of reactive power and power losses in transmission lines. The harmonics also cause electromagnetic interference 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 impedanceis, so that non-sinusoidal voltages appears at several points of the mains. It brings out overheating of line,transformers and generators due to the iron losses. -　Methods for limitation and elimination of disturbances and harmonic pollution in the power system have been widely investigated. This problem rapidly intensifies with the increasing amount of electronic equipment (computers, radio set, printers, TV sets etc.). This equipment, a nonlinear load, is a source of current harmonics, which produce increase of reactive power and power losses in transmission lines. The harmonics also cause electromagnetic interference 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 impedanceis, so that non-sinusoidal voltages appears at several points of the mains. It brings out overheating of line,transformers and generators due to the iron losses.