ECONOMICALLY CONTROLLING POWER LINE HARMONIC DISTORTION CAUSED BYADJUSTABLE FREQUENCY DRIVES

摘要

Adjustable frequency drives are commonly used tornimprove the efficiency and reduce the maintenancernrequirements of a building’s heating, ventilation and airrnconditioning (HVAC) system. However, these drives,rnalong with other non-linear electronic loads in thernbuilding, can have an impact on the quality of thernbuilding’s electrical power and the reliable operation ofrnother equipment.rnThis paper considers factors that are important inrnanalyzing the potential for problems related to harmonicrndistortion in a building’s electrical system. A range ofrncommon harmonic control methods is analyzed to showrnthe effectiveness and relative merits of each. This paperrnwill consider low voltage drives (for power lines with anrnrms voltage of up to 600 V) because this is the mostrncommon voltage range used in commercial buildings.rnWhile medium voltage drives will of necessity have somerndesign differences, many of the basic concepts consideredrnhere can often be applied to medium voltage drives.