ABSTRACT
Electronic equipment connected to main components interact with the supply grid to a varying extent. Passive loads such as resistive heaters draw current linearly and do not affect the operation of other equipment connected to the same mains. Most power electronic devices switch the current on and off rapidly and this causes disturbances in the main network in the form of additional current harmonics. These harmonics are generated by the switching action in the equipment and may interfere with sensitive electronic devices connected to the same network. Legislation has been introduced that specifies acceptable levels of reflected harmonics from power electronic equipment into the mains. Utility companies do not like this switching behavior because it causes them to supply extra power to the equipment and install extra thick cabling to account for circulating current. Some of the power electronic topologies, mainly DC-DC converters, offer the characteristic of making any switching load appear as resistive load. In other words, these controllers draw the line current proportional to the line voltage. This chapter discusses various power electronic converters for power factor correction and special converters used for motor drives to achieve good power factor.
