Page 144 - Power Quality in Electrical Systems

126 Chapter Eight

can be maintained or replaced without interrupting power supply to
critical loads [8.4]. The description of reliability includes the Tier con-
cept for definitions of availability time, while Chapter 13 provides
details of standby power systems.

Summary

Deviations in source voltage and current for critical load equipment
must be corrected to insure reliable operation of the equipment.
Industry standards, such as CBEMA, define corrected values. Methods
of correction include filters, compensators, special transformers, and
battery-inverter UPSs. The UPS modules are utilized singly and in
groups as a function of the requirements of the load. Engine-genera-
tor sets serve to extend the operating time of batteries in UPS.
Reliability of systems supported by UPS is measured in percent avail-
ability, from Tier I to Tier IV.

References
[8.1] “Reliability Models for Electric Power Systems,” whitepaper #23, American Power
Conversion (APC), 2003.
[8.2] A. T. de Almedia, F.J.T.E. Ferreira, and D. Both, “Technical and Economical
Considerations in the Application of Variable-Speed Drives with Electric Motor
Systems,” IEEE Transactions on Industry Applications, vol. 41, no. 1, Jan./Feb.
2005, pp. 188–199.
[8.3] M. Andressen, “Real Time Disturbance Analysis and Notification,” Power Quality
Conference ‘04, Chicago, IL.
[8.4] R. J. Yester, “New Approach to High Availability Computer Power System Design,”
EC&M, January 2006, pp. 18–24.
[8.5] W. P. Turner IV, J. H. Seader, and K. G. Brill, “Industry Standard Tier Classifications
Define Site Infrastructure Performance,” whitepaper, The Uptime Institute,
2001–2005.
[8.6] J. W. Gray and F. J. Haydock, “Industrial Power Quality Considerations When
Installing Adjustable Speed Drive Systems,” IEEE Trans. on Ind. Appl., vol. 32, no. 3,
May/June 1986, pp. 646–652.
[8.7] L. Manz, “Applying Adjustable-Speed Drives to Three-Phase Induction NEMA
Frame Motors,” IEEE Trans. on Ind. Appl., vol. 33, no. 2, March/April 1997.
[8.8] A. von Jouanne, P. N. Enjeti, and B. Banerjee, “Assessment of Ride-Through
Alternatives for Adjustable Speed Drives,” IEEE Trans. on Ind. Appl., vol. 35,
no. 4, July/August 1999, pp. 908–916.
[8.9] T. Jimichi, H. Fujita, and H. Akagi, “Design and Experimentation of a Dynamic
Voltage Restorer Capable of Significantly Reducing an Energy-Storage Element,”
Conference Record, 2005 Fortieth IAS Annual Meeting, pp. 896–903.
[8.10] A. Kusko, Emergency Standby Power Systems, McGraw-Hill, New York, 1989.
[8.11] J. G. Boudrias, “Harmonic Mitigation, Power Factor Connection, and Energy.
Saving with Proper Transformers and Phase Shifting Techniques,” Power Quality
Conference, ‘04, Chicago, IL.
[8.12] L. F. Blume, G. Camilli, A. Boyajian, and V. M. Montsinger, Transformer
Engineering, John Wiley, 1938.
[8.13] R. C. Dugan, M. F. McGranaghan, S. Santosa, and H. W. Beaty, Electrical Power
Systems Quality, 2nd edition, McGraw-Hill, 2002.