中国电机工程学报
中國電機工程學報
중국전궤공정학보
ZHONGGUO DIANJI GONGCHENG XUEBAO
2014年
12期
1989-1995
,共7页
李博江%文习山%严玉婷%李博洋%王贺%于建立
李博江%文習山%嚴玉婷%李博洋%王賀%于建立
리박강%문습산%엄옥정%리박양%왕하%우건립
变压器%中性点%空气水流%工频放电%气泡%组合流体
變壓器%中性點%空氣水流%工頻放電%氣泡%組閤流體
변압기%중성점%공기수류%공빈방전%기포%조합류체
transformer%neutral point%air and water flow%power frequency discharge%bubbles%combined fluid
为克服变压器中性点传统空气保护间隙存在的缺陷,提出了“气水间隙”概念,并在武汉大学电气工程学院高电压与绝缘技术试验室进行了气水间隙工频放电特性试验。试验结果表明:当水流从低压电极喷射到高压电极时,间隙很难击穿;当间隙总长度固定,工频放电电压随喷射水流长度减小呈先减小后增大的变化趋势;当喷射水流长度略小于间隙总长度时,工频放电电压与间隙总长度呈线性递增关系;同等长度的气水间隙比空气间隙和全水间隙易击穿,等等。基于气泡击穿理论和空气与水不同的电特性,对试验观察到的放电现象、规律和机制进行分析,指出水流的击穿起因是其中的“气泡桥”的存在和发展,以及水中电离子作用的结果;在气水间隙中,空气段率先击穿形成的电弧高温加热水流促使水中气泡的产生和发展,最终导致水流段的击穿;气水间隙放电特性曲线具有先减小后增大的变化趋势特征是空气和水流不同的电特性相互作用的结果;将气水间隙应用于变压器中性点保护,具有较可观的研究价值和应用前景。
為剋服變壓器中性點傳統空氣保護間隙存在的缺陷,提齣瞭“氣水間隙”概唸,併在武漢大學電氣工程學院高電壓與絕緣技術試驗室進行瞭氣水間隙工頻放電特性試驗。試驗結果錶明:噹水流從低壓電極噴射到高壓電極時,間隙很難擊穿;噹間隙總長度固定,工頻放電電壓隨噴射水流長度減小呈先減小後增大的變化趨勢;噹噴射水流長度略小于間隙總長度時,工頻放電電壓與間隙總長度呈線性遞增關繫;同等長度的氣水間隙比空氣間隙和全水間隙易擊穿,等等。基于氣泡擊穿理論和空氣與水不同的電特性,對試驗觀察到的放電現象、規律和機製進行分析,指齣水流的擊穿起因是其中的“氣泡橋”的存在和髮展,以及水中電離子作用的結果;在氣水間隙中,空氣段率先擊穿形成的電弧高溫加熱水流促使水中氣泡的產生和髮展,最終導緻水流段的擊穿;氣水間隙放電特性麯線具有先減小後增大的變化趨勢特徵是空氣和水流不同的電特性相互作用的結果;將氣水間隙應用于變壓器中性點保護,具有較可觀的研究價值和應用前景。
위극복변압기중성점전통공기보호간극존재적결함,제출료“기수간극”개념,병재무한대학전기공정학원고전압여절연기술시험실진행료기수간극공빈방전특성시험。시험결과표명:당수류종저압전겁분사도고압전겁시,간극흔난격천;당간극총장도고정,공빈방전전압수분사수류장도감소정선감소후증대적변화추세;당분사수류장도략소우간극총장도시,공빈방전전압여간극총장도정선성체증관계;동등장도적기수간극비공기간극화전수간극역격천,등등。기우기포격천이론화공기여수불동적전특성,대시험관찰도적방전현상、규률화궤제진행분석,지출수류적격천기인시기중적“기포교”적존재화발전,이급수중전리자작용적결과;재기수간극중,공기단솔선격천형성적전호고온가열수류촉사수중기포적산생화발전,최종도치수류단적격천;기수간극방전특성곡선구유선감소후증대적변화추세특정시공기화수류불동적전특성상호작용적결과;장기수간극응용우변압기중성점보호,구유교가관적연구개치화응용전경。
To overcome the disadvantages of traditional protection air gaps of transformer neutral points, the concept of the gap of water and air was presented. The power frequency discharge test between the gap of air and water was conducted in high voltage test room of School of Electrical Engineering in Wuhan University. Test results show that breakdown of the gap is very hard to occur when flow is jetted to the high voltage electrode from low voltage electrode; power frequency discharge voltage will decrease first and increase then with flow length decreasing when the total length of the gap is constant; there is a linear increasing relation between power frequency discharge voltage and total length of the gap when the flow length is somewhat less than the total length of gap; breakdown of the gap of air and water can occur more easily than air gap and water gap of the same length. Based on the bubble breakdown theory and different electrical characteristics of air and water, the law and phenomenon obtained from the test is discussed theoretically from mechanism. It is pointed out that the breakdown of water flow results from existence and the development of ‘bubble bridge’ and the effect of electric ion in water; in the gap of air and water, high temperature of arc generated from the first breakdown of air segment heats water flow to promote the generation and development of bubbles in water, and the breakdown of water flow segment can be generated finally; the discharge characteristics curve of the gap of air and water going down first and rising then results from different electrical features of air and water. The gap of air and water used on transformer neutral points protection has high research value and broad application prospect.