一起110 kV母差保護(hù)誤動(dòng)事件分析及改進(jìn)
黃楊明，任欣元，莫靖，李強(qiáng)
廣東電網(wǎng)公司佛山供電局，廣東 佛山 528000
摘 要：分析了某220kV變電站發(fā)生的一起110kV母差保護(hù)誤動(dòng)事件，得出了本次誤動(dòng)的根本原因在于外部故障切除后，母差保護(hù)立刻退出電流波形識(shí)別閉鎖判據(jù)這一邏輯缺陷。考慮到電流在電流互感器(CT)飽和后每一過零點(diǎn)都有一段3～4ms真實(shí)傳變區(qū)，提出過零點(diǎn)重啟波形識(shí)別判據(jù)，直到波形識(shí)別出CT飽和消失，以解決區(qū)外故障切除后，在衰減過程中的非周期分量影響下，母差保護(hù)誤動(dòng)問題。
關(guān)鍵詞：母差保護(hù)；CT飽和；誤動(dòng)；波形識(shí)別；非周期分量
中圖分類號(hào)：TM773 文獻(xiàn)標(biāo)識(shí)碼：B 文章編號(hào)：1007-3175(2013)02-0027-04
Analysis and Improvement of 110 kV Busbar Differential Protection Misoperation Accident
HUANG Yang-ming, REN Xin-yuan, MO Jing, LI Qiang
Foshan Power Supply Bureau, Guangdong Power Grid Corp, Foshan 528000, China
Abstract: Analysis was made to the accidental operation of a 110 kV busbar differential protection in certain 220 kV substation. The fundamental reason of the accidental operation was the defective logic that busbar differential protection immediately exited the current waveform recognition locking criterion after the removal of external faults. Considering that after the current transformer (CT) saturated in each zero crossing, the current has a 3 to 4 ms real transmission area, this paper put forward that the current waveform recognition criterion was restarted in each zero crossing until the CT saturation disappeared, to solve the problem of busbar differential protection maloperation under the influence of the aperiodic component in the attenuation process after the removal of external faults.
Key words: busbar differential protection; current transformer saturation; misoperation; waveform identification; aperiodic component
參考文獻(xiàn)
[1] 王鵬程.刀閘輔助觸點(diǎn)狀態(tài)出錯(cuò)對(duì)母差保護(hù)的影響[J].電力系統(tǒng)保護(hù)與控制，2010，38(5)：124-126.
[2] 黃小波，王新宇，林湘寧.適用于微機(jī)母線保護(hù)的CT飽和識(shí)別新判據(jù)[J].湖北電力，2006，30(1)：23-24.
[3] 舒逸石，馬勇，于培杰.淺談母差保護(hù)微機(jī)化的幾點(diǎn)感受[J].電力系統(tǒng)保護(hù)與控制，2009，37(14)：116-117.
[4] 李建新，桂小軍，俞鏞偉.一種適用于母差保護(hù)的CT飽和判據(jù)[J].繼電器，2000，38(3)：44-45.
[5] 趙永彬，陸于平.一種基于異步法的母線保護(hù)中電流互感器飽和判據(jù)[J].電網(wǎng)技術(shù)，2006，30(5)：86-90.
[6] 陳利軍，龍翔，楊奇遜.基于采樣值的CT飽和檢測(cè)方案的研究[J].繼電器，2000，28(8)：19-21.
