Proceedings of the KIEE Conference (대한전기학회:학술대회논문집)
- 2009.07a
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- Pages.1948_1949
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- 2009
A Analysis of DC Control Circuit Transient and a Study of Auxiliary Relay Design Compatability in the Power Plant
발전소 직류 제어회로 과도현상 분석 및 보조계전기 선정 적합성 검토
- Seon, Hyun-Gyu (Nuclear Engineering & Technology Institute) ;
- Hong, Young-Hee (Korea Hydro & Nuclear Power Co.)
- Published : 2009.07.14
Abstract
All the power generating station require dc auxiliary power systems to operate those dc components that must be available if a loss of ac power occur. Some examples of such components are auxiliary motors, circuit breakers, relays and solenoids. The dc source may be one common battery for both power and control or two separate batteries; one for power and another for control. Typically, a dc auxiliary power system is designed as an ungrounded system, instead of grounded system, so that a low-resistance ground fault on one of its two polarities will not affect the operation of the system, thus increasing system reliability and continuity of service. A ground detector should provide a high polarity-to-ground resistance so that a single ground fault occurring on the system will not affect the operation of that system. Sensitive relays have been known to energize momentarily while the cable and capacitive charge to ground shifts[1]. A power station had experienced this kind of incident and performed root cause analysis based on PC based simulation program known as PSpice. This simulation showed adapted relays on the system energize momentarily and design criteria on this relay should be corrected.
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