电力勘测设计
電力勘測設計
전력감측설계
ELECTRIC POWER SURVEY
2015年
8期
28-31
,共4页
发电厂%500 kV并联电抗器%串内%保护CT配置
髮電廠%500 kV併聯電抗器%串內%保護CT配置
발전엄%500 kV병련전항기%천내%보호CT배치
power plants%500 kV shunt-wound reactors%in series%protective CT scheme
发电厂内广泛采用3/2接线的500 kV系统，经过经济技术论证合理时，500 kV并联电抗器可接入串内。由于并联电抗器额定电流较小而串内可能的穿越电流较大，典型的电流互感器(Current Transformer, CT)配置方案无法满足保护装置可靠性和灵敏性的要求。改进的保护CT配置方案需在分支上增加两组CT，设置电抗器引线保护和电抗器本体保护，分别用于保护断路器、分支部分和电抗器本体部分。通过详细分析和计算，证明改进的保护CT配置方案是可行的。
髮電廠內廣汎採用3/2接線的500 kV繫統，經過經濟技術論證閤理時，500 kV併聯電抗器可接入串內。由于併聯電抗器額定電流較小而串內可能的穿越電流較大，典型的電流互感器(Current Transformer, CT)配置方案無法滿足保護裝置可靠性和靈敏性的要求。改進的保護CT配置方案需在分支上增加兩組CT，設置電抗器引線保護和電抗器本體保護，分彆用于保護斷路器、分支部分和電抗器本體部分。通過詳細分析和計算，證明改進的保護CT配置方案是可行的。
발전엄내엄범채용3/2접선적500 kV계통，경과경제기술론증합리시，500 kV병련전항기가접입천내。유우병련전항기액정전류교소이천내가능적천월전류교대，전형적전류호감기(Current Transformer, CT)배치방안무법만족보호장치가고성화령민성적요구。개진적보호CT배치방안수재분지상증가량조CT，설치전항기인선보호화전항기본체보호，분별용우보호단로기、분지부분화전항기본체부분。통과상세분석화계산，증명개진적보호CT배치방안시가행적。
The“3/2” connection and 500 kV voltage system are widely used in power plants. The shunt-wound reactors can be connected in series after economical and technical analysis. The rated current of shunt-wound reactors is much less than the possible cross current within the series. So the typical protective CT scheme can’t satisfy the reliability and sensibility requests of protection devices. In the improved protective CT scheme, two sets of CT need be additionally provided in the offset. The offset protection and reactor protection are provided for protecting the part of circuit breakers, offset and the part of reactor. The improved protective CT scheme has been proved to be feasible through detailed analysis and calculations.
