Power quality issues related to variable-frequency drives.

摘要

Variable Frequency Drives (VFDs) are widely used in industrial and commercial applications due to their ability to reduce energy demand. A VFD, however, is not only sensitive to poor power quality (e.g., voltage transients, sags, and swells), but is also considered as a source of harmonic pollution. Harmonic currents generated by VFDs are often blocked by passive shunt or series filters. The impact of line reactors on voltage disturbances originating from the utility side is not fully explored. Other issues like the use of output reactors with long motor leads and grounding of the power distribution system are also important issues with regard to the use of VFD.; The proposed research is to investigate power quality issues related to VFDs, broadly classified into three objectives: (a) impact of input reactors on power quality, under power system disturbances from the utility side; (b) impact of output reactors on the quality of power supplied to motors, when fed from sufficiently long cables; (c) impact of operating a VFD from an ungrounded distribution system The study would be carried out using the computer simulation tool PSPICE.