AbstractsEngineering

The problem of harmonic pollution in power distribution lines has generated significant interest over the last years The most common sources of harmonics are nonlinear loads that draw non sinusoidal currents causing harmonic voltage drops across the network impedance resulting in distorted voltages and line currents thus reducing the supply power factor Additional consequences of harmonic pollution include overheating of the equipments increased power losses which result in low efficiency humming in telecommunication lines and computer network failure A collection of passive and active Power Factor Correction techniques has been proposed Among them passive filters have the limitations of fixed compensation and large size whereas the active PFC techniques are used in majority of the applications due to their improved performance Switched Mode Power Supplies have been in use as active PFC to correct the poor power factor and to reduce the high harmonic current contents An ideal PFC used for input current shaping should emulate a resistor on the supply side while maintaining a regulated output voltage newline%%%References p.155-162