Voltage sag relief: Guidelines to estimate DVR equipment ratings

Conference · Fri Nov 01 04:00:00 EST 1996

OSTI ID:389942

Nelson, R J; Legro, J R; Gurlaskie, G T ^[1]; Woodley, N H; Sarkozi, M ^[2]; Sundaram, A ^[3]

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1. Westinghouse Electric Corp., Orlando, FL (United States)
2. Westinghouse Electric Corp., Pittsburgh, PA (United States)
3. Electric Power Research Inst., Palo Alto, CA (United States)

Economic pressures on industry to automate processes and improve efficiencies have resulted in a steady increase in the number and size of loads that are not tolerant of voltage sags. Since sags are the most common form of disruption (6 to 10 times more common than interruptions), this problem demands a solution. One initiative to address this issue, sponsored by the Electric Power Research Institute (EPRI), is the development of the Dynamic Voltage Restorer (DVR). The DVR uses a power electronic inverter to inject voltage in series with the source to supplement the source voltage during system voltage sags. Power can be transferred from high-voltage phases to low-voltage phases during unbalanced faults. Short time energy storage can be used to provide the supplemental energy needed to keep load voltage at acceptable levels. A study published last year showed that DVRs could be economically applied to many utility distribution stations. Analysis indicates that deep voltage sags, even of relatively short duration, can have significant costs because of the proliferation of voltage-sensitive computer-based and variable speed drive loads. The fraction of load that is sensitive to low voltage is expected to grow rapidly in the coming decades. This paper describes the DVR, summarizes previous studies related to sag mitigation and application of the DVR. It also provides a simple methodology to estimate the size of a DVR necessary to minimize total customer costs.

• OSTI ID: 389942
• Report Number(s): CONF-960426--
• Country of Publication: United States
• Language: English

Related Subjects

24 POWER TRANSMISSION AND DISTRIBUTION
POWER DISTRIBUTION SYSTEMS
POWER TRANSMISSION
STABILIZATION
VOLTAGE DROP
VOLTAGE REGULATORS