10 kV配電網中性點經小電阻接地方式分析
顧韌，閆少波
(蘇州供電公司，江蘇 蘇州 215004)
摘 要： 介紹了10 kV 配電網中性點經小電阻接地方式，通過對線路單相接地時的電流流向和保護整定方式的分析，討論了一起線路高阻接地時接地變總后備誤動的案例，并對線路和接地變零序電流整定值的配合方式給出了建議。結果表明，中性點經小電阻接地系統中，若作為整個10 kV 系統總后備的接地變高壓零流整定值小于出線Ⅱ段零序整定值，可能會造成總后備誤動作。
關鍵詞： 小電阻接地；單相接地；總后備；誤動
中圖分類號：TM645 文獻標識碼：B 文章編號：1007-3175(2015)05-0037-04
Analysis of Low-Resistance Neutral Point Grounding Mode in 10 kV Power Distribution Grid
GU Ren, YAN Shao-bo
（Suzhou Power Supply Company, Suzhou 215004, China）
Abstract: Introduction was made to the low-resistance neutral point grounding mode in 10 kV power distribution grid. Analysis was made to the current direction and protection setting mode when the line single phase grounding. This paper discussed a case of total reserve unwanted operation of grounding transformer when the line high-resistance grounding and suggested that the line should fit for the setting value of grounding transformer zero-sequence current. The result shows that in the low-resistance neutral point grounding system, if the setting value of grounding transformer zero-sequence current acting as the 10 kV system total reserve is less than that of the outgoing line secondary section, the total reserve will turn up unwanted operation.
Key words: low-resistance grounding; single phase grounding; total reserve; unwanted operation
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