昆明理工大学学报（自然科学版）
昆明理工大學學報（自然科學版）
곤명리공대학학보（자연과학판）
JOURNAL OF KUNMING UNIVERSITY OF SCIENCE AND TECHNOLOGY（SCIENCE AND TECHNOLOGY）
2015年
2期
73-79,129
,共8页
孙向飞%周建萍%夏聆峰%孙士云
孫嚮飛%週建萍%夏聆峰%孫士雲
손향비%주건평%하령봉%손사운
和应涌流%电流互感器饱和%差动保护%变化器
和應湧流%電流互感器飽和%差動保護%變化器
화응용류%전류호감기포화%차동보호%변화기
sympathetic inrush%current transformer saturation%differential protection%transformer
目前和应涌流造成差动保护误动的报道及原因分析，主要针对独立的单个事件，缺乏对和应涌流导致差动保护误动模式的全面分析以及误动本质原因的深入研究。为此，在全面统计分析国内外和应涌流导致差动保护误动实例的基础上，归纳分析了发生和应涌流的运行模式，分别研究了并联与级联和应涌流导致 CT 暂态饱和后对差流的二次谐波和间断角的影响，揭示了级联和应涌流更容易引起差动保护误动的内在原因，并依据实际运行情况，重点考虑负荷电流的影响。研究表明，并联和应涌流易导致系统侧 CT 饱和，此时差流即为和应涌流，差流基波分量减小，而负荷电流为正弦量不含二次谐波，即差流的二次谐波含量上升，差流间断角亦较大；而级联和应涌流易引起负荷侧 CT 饱和，此时差流为负的和应涌流，差流的二次谐波分量减小，差流间断角亦变得很小，可能导致现有的涌流制动环节失效，容易引起变压器差动保护误动作。仿真和实例统计结果均验证了理论分析的正确性。
目前和應湧流造成差動保護誤動的報道及原因分析，主要針對獨立的單箇事件，缺乏對和應湧流導緻差動保護誤動模式的全麵分析以及誤動本質原因的深入研究。為此，在全麵統計分析國內外和應湧流導緻差動保護誤動實例的基礎上，歸納分析瞭髮生和應湧流的運行模式，分彆研究瞭併聯與級聯和應湧流導緻 CT 暫態飽和後對差流的二次諧波和間斷角的影響，揭示瞭級聯和應湧流更容易引起差動保護誤動的內在原因，併依據實際運行情況，重點攷慮負荷電流的影響。研究錶明，併聯和應湧流易導緻繫統側 CT 飽和，此時差流即為和應湧流，差流基波分量減小，而負荷電流為正絃量不含二次諧波，即差流的二次諧波含量上升，差流間斷角亦較大；而級聯和應湧流易引起負荷側 CT 飽和，此時差流為負的和應湧流，差流的二次諧波分量減小，差流間斷角亦變得很小，可能導緻現有的湧流製動環節失效，容易引起變壓器差動保護誤動作。倣真和實例統計結果均驗證瞭理論分析的正確性。
목전화응용류조성차동보호오동적보도급원인분석，주요침대독립적단개사건，결핍대화응용류도치차동보호오동모식적전면분석이급오동본질원인적심입연구。위차，재전면통계분석국내외화응용류도치차동보호오동실례적기출상，귀납분석료발생화응용류적운행모식，분별연구료병련여급련화응용류도치 CT 잠태포화후대차류적이차해파화간단각적영향，게시료급련화응용류경용역인기차동보호오동적내재원인，병의거실제운행정황，중점고필부하전류적영향。연구표명，병련화응용류역도치계통측 CT 포화，차시차류즉위화응용류，차류기파분량감소，이부하전류위정현량불함이차해파，즉차류적이차해파함량상승，차류간단각역교대；이급련화응용류역인기부하측 CT 포화，차시차류위부적화응용류，차류적이차해파분량감소，차류간단각역변득흔소，가능도치현유적용류제동배절실효，용역인기변압기차동보호오동작。방진화실례통계결과균험증료이론분석적정학성。
At present,the analysis and research of differential protection mal -operation caused by sympathetic inrush are not sufficient because reports and reason analysis are mainly focused on irrelevant single incidents.The occurrence modes and characteristics are therefore firstly summarized based on statistics and analysis of differential protection mal -operation cases caused by sympathetic inrush reported at home and abroad.Then,the influences of CT saturation on the second harmonic proportion and dead angle of differential current are investigated.The internal reasons for series sympa-thetic inrush causing differential protection mal -operation easier are also revealed.Moreover,according to the actual op-erating conditions,the impact of load current is mainly considered.The results show that parallel sympathetic inrush may lead to system-side CT saturation;second harmonic ratio of differential current increases and dead angle is large.On the contrary,series sympathetic inrush easily causes load -side CT saturation,and this will lead to second harmonic ratio lower than threshold and dead angle reduced.Thus,second harmonic restraint is invalid and differential protection may mal -operate.The simulation and case statistics verify the validity of theoretical analysis.
