Page 59 - Power Quality in Electrical Systems

42 Chapter Three

Disturbance type Description Causes
Flicker Small repetitive fluctuations in the Pulsating load
voltage level

Notches Repetitive dips in the line voltage, Current commutation in controlled or
with short durations uncontrolled three-phase rectifier
circuits

Waveform distortion Deviation from ideal sine wave due Rectifiers, phase-angle controllers,
to the presence of harmonics or other nonlinear and/or intermittent
interharmonics loads

Frequency variation Deviation of the frequency from the Poorly regulated utility equipment,
nominal value emergency power generator

Outage Zero-voltage condition of a single Load equipment failure, ground fault,
phase or several phases in a multi- utility equipment failure, accidents,
phase system, for more than a half- lightning, acts of nature
period
Figure 3.22 (Continued)

References
[3.1] IEEE, “IEEE Recommended Practice for Monitoring Electric Power Quality,” IEEE
Std. 1159-1995.
[3.2] K. J. Cornick and H. Q. Li, “Power Quality and Voltage Dips: Problems,
Requirements, Responsibilities,” Proceedings of the 5th International Conference on
Advances in Power System Control, Operation, and Management, APSCOM 2000,
Hong Kong, October 2000, pp. 149–156.
[3.3] IEEE, “IEEE Recommended Practice for Emergency and Standby Power Systems
for Industrial and Commercial Applications,” IEEE Std. 446-1995 (The Orange
Book).
[3.4] C.-S. Wang and M. J. Devaney, “Incandescent Lamp Flicker Mitigation and
Measurement,” IEEE Transactions on Instrumentation and Measurement, vol. 53,
no. 4, August 2004, pp. 1028–1034.
[3.5] IEEE, “IEEE Recommended Practices and Requirements for Harmonic Control in
Electrical Power Systems,” IEEE Std. 519-1992, revision of IEEE Std. 519-1981.
[3.6] R. Redl, R. and A. S. Kislovski, “Telecom Power Supplies and Power Quality,”
Proceedings of the 17th International Telecommunications Energy Conference, INT-
ELEC ‘95, October 29 to November 1, 1995, pp. 13–21.