陳永明,湯大海,劉 昶,孫東杰,姜正馳,馬駿毅,笪 濤
(國(guó)網(wǎng)江蘇省電力有限公司鎮(zhèn)江供電分公司,江蘇 鎮(zhèn)江,212001)
傳統(tǒng)的變壓器差動(dòng)保護(hù)電流相位補(bǔ)償方案有2種:一是基于硬件移相的電流相位補(bǔ)償方案[1-2],比如YNd11變壓器三角側(cè)電流互感器(TA)的二次采用Y-12接線形式,同時(shí)星側(cè)TA的二次繞組采用d-11接線形式;二是通過(guò)軟件移相實(shí)現(xiàn)目標(biāo)情況的電流相位補(bǔ)償,變壓器各側(cè)的TA二次繞組采用星形接法,利用算式和軟件程序來(lái)完成電流相位補(bǔ)償。文獻(xiàn)[3]和文獻(xiàn)[4]提出了一種新型變壓器相位補(bǔ)償方案:即先采用1次硬件補(bǔ)償,將YNd系列變壓器接線組別的相位補(bǔ)償問(wèn)題轉(zhuǎn)化為現(xiàn)已實(shí)現(xiàn)的YNd11或YNd1接線的變壓器差動(dòng)保護(hù)電流相位補(bǔ)償問(wèn)題,再應(yīng)用軟件相位補(bǔ)償,實(shí)現(xiàn)變壓器YNd類(lèi)接線的差動(dòng)保護(hù)電流相位補(bǔ)償。該文通過(guò)進(jìn)一步分析YNd系列變壓器接線組別的特點(diǎn),提出2種基于2次硬件補(bǔ)償?shù)男滦妥儔浩鞑顒?dòng)保護(hù)電流相位補(bǔ)償方案。
將YNd接線變壓器中的1、3、5、7、9和11點(diǎn)接線,分成YNd11系列和YNd1接線系列兩類(lèi)[5]。其中,11點(diǎn)接線組別系列包括了3、7和11點(diǎn)3種形式,見(jiàn)圖1,(a)即11點(diǎn)接線系列的接線示意圖,(b)即11點(diǎn)接線形式的接線示意圖,(c)即3點(diǎn)接線形式的接線示意圖,(d)即7點(diǎn)接線形式的接線示意圖;1點(diǎn)接線組別系列包括了1、5和9點(diǎn)3種形式,見(jiàn)圖2,其中(a)即1點(diǎn)接線系列的接線示意圖,(b)即1點(diǎn)接線形式的接線示意圖,(c)即5點(diǎn)接線形式的接線示意圖,(d)即9點(diǎn)接線形式的接線示意圖。
圖1 YNd11系列變壓器接線圖Fig.1 YNd11 series transformer wiring diagram
圖2 YNd1系列變壓器接線圖Fig.2 YNd1 series transformer wiring diagram
結(jié)合圖1和圖2接線圖可知, 若將YNd1變壓器與YNd5變壓器的高壓側(cè)A、B、C各相電流看作同相,則YNd1變壓器與YNd5變壓器的低壓側(cè)繞組a、b、c各相電流對(duì)應(yīng)相位關(guān)系為相差120°。同理,YNd11變壓器與YNd5變壓器的低壓側(cè)繞組a、b、c各相電流對(duì)應(yīng)相位關(guān)系為反相,即相差180°,具體對(duì)應(yīng)相位見(jiàn)表1。由表1可間接得到Y(jié)Nd11變壓器低壓側(cè)繞組與YNd1變壓器的低壓側(cè)繞組各相電流相位對(duì)應(yīng)關(guān)系。
表1 YNd1、YNd5與YNd11變壓器低壓側(cè)繞組對(duì)應(yīng)相位關(guān)系Table 1 Phase relationship of low voltage side winding of YNd1, YNd5 and YNd11 transformer
同理, YNd9與YNd3接線變壓器低壓側(cè)繞組各相電流相位關(guān)系是反相,即相差180°。YNd1接線變壓器與YNd9接線變壓器的低壓側(cè)繞組相電流關(guān)系,見(jiàn)表2。以YNd9為中間過(guò)渡,可得到Y(jié)Nd3接線變壓器與YNd1接線變壓器低壓側(cè)的繞組各相電流相位關(guān)系。
表2 YNd1、YNd9與 YNd3變壓器低壓側(cè)繞組對(duì)應(yīng)相位關(guān)系Table 2 Phase relationship of low voltage side winding of YNd1, YNd9 and YNd3 transformer
結(jié)合表1和表2可得出YNd11接線變壓器與YNd3接線變壓器差動(dòng)保護(hù)電流相位補(bǔ)償方案。即 由YNd11變壓器相位補(bǔ)償轉(zhuǎn)換為YNd5變壓器相位補(bǔ)償,再由YNd5變壓器相位補(bǔ)償轉(zhuǎn)換為YNd1變壓器相位補(bǔ)償;由YNd3變壓器相位補(bǔ)償轉(zhuǎn)換為YNd9變壓器相位補(bǔ)償,再由YNd9變壓器相位補(bǔ)償轉(zhuǎn)換為YNd1變壓器相位補(bǔ)償,通過(guò)這2次硬件相位補(bǔ)償?shù)霓D(zhuǎn)換,將3點(diǎn)或11點(diǎn)接線的變壓器差動(dòng)保護(hù)電流相位補(bǔ)償問(wèn)題轉(zhuǎn)變?yōu)?點(diǎn)接線變壓器差動(dòng)保護(hù)電流相位補(bǔ)償問(wèn)題,通過(guò)1點(diǎn)接線形式的微機(jī)變壓器差動(dòng)保護(hù)裝置軟件相位補(bǔ)償,實(shí)現(xiàn)3點(diǎn)和11點(diǎn)接線情況的相位補(bǔ)償,圖3為具體原理接線示意。
圖3 YNd11和YNd3接線變壓器差動(dòng)保護(hù)電流相位補(bǔ)償原理示意圖Fig.3 Schematic diagram of current phase compensation principle for differential protection of YNd11 and YNd3 connected transformer
同理,將YNd1與YNd7接線變壓器高壓側(cè)繞組對(duì)應(yīng)的各相電流同相,由圖1和圖2的接線形式可知YNd1與YNd7接線變壓器低壓側(cè)繞組各相電流相位關(guān)系為反相,即相差180°。再由YNd11與 YNd7接線的變壓器低壓側(cè)繞組各相電流關(guān)系,得到Y(jié)Nd1和 YNd11接線變壓器低壓側(cè)繞組的各相電流相位關(guān)系,見(jiàn)表3。
表3 YNd11、YNd7和YNd1變壓器低壓側(cè)繞組對(duì)應(yīng)相位關(guān)系Table 3 Phase relationship of low voltage side winding of YNd11, YNd7 and YNd1 transformer
同理,由YNd9與YNd3接線變壓器低壓側(cè)繞組各相電流相位關(guān)系是反相,即相差180°。再由YNd11與YNd3接線的變壓器低壓側(cè)繞組各相電流關(guān)系,可得到Y(jié)Nd9接線與YNd11接線變壓器低壓側(cè)繞組的各相電流關(guān)系,見(jiàn)表4。
由表3和表4可得出YNd1接線變壓器和YNd9接線變壓器差動(dòng)保護(hù)電流的相位補(bǔ)償方案。即由YNd1變壓器相位補(bǔ)償轉(zhuǎn)換為YNd7變壓器相位補(bǔ)償,再由YNd7變壓器相位補(bǔ)償轉(zhuǎn)換為YNd11變壓器相位補(bǔ)償;或由YNd9變壓器相位補(bǔ)償轉(zhuǎn)換為YNd3變壓器相位補(bǔ)償,再由YNd3變壓器相位補(bǔ)償轉(zhuǎn)換為YNd11變壓器相位補(bǔ)償,通過(guò)這2次硬件相位補(bǔ)償?shù)霓D(zhuǎn)換,將1點(diǎn)或9點(diǎn)接線變壓器的差動(dòng)保護(hù)電流相位補(bǔ)償問(wèn)題轉(zhuǎn)變?yōu)榱?1點(diǎn)接線變壓器差動(dòng)保護(hù)電流相位補(bǔ)償問(wèn)題,通過(guò)11點(diǎn)接線微機(jī)變壓器差動(dòng)保護(hù)裝置軟件相位補(bǔ)償,實(shí)現(xiàn)1點(diǎn)和9點(diǎn)接線變壓器差動(dòng)保護(hù)電流的相位補(bǔ)償,圖4為具體原理接線示意圖。
表4 YNd11、YNd3與YNd9變壓器低壓側(cè)繞組對(duì)應(yīng)相位關(guān)系Table 4 Phase relationship of low voltage side winding of YNd11, YNd3 and YNd9 transformer
圖4 YNd1和 YNd9接線變壓器差動(dòng)保護(hù)電流相位補(bǔ)償原理示意圖Fig.4 Schematic diagram of current phase compensation principle for differential protection of YNd1 and YNd9 connected transformer
YNd11變壓器接線圖如圖5(a)所示,若把YNd11變壓器接線圖的高壓側(cè)A、B、C各相樁頭變?yōu)镃、B、A,低壓側(cè)繞組a、b、c各相樁頭變?yōu)閏、b、a,如圖5(b)示。則會(huì)發(fā)現(xiàn)YNd11變壓器接線就變?yōu)榱薡Nd1變壓器接線,由此可知YNd11變壓器與YNd1變壓器高壓側(cè)A、B、C和低壓側(cè)繞組a、b、c各相電流的對(duì)應(yīng)相位關(guān)系,見(jiàn)表5。
圖5 YNd11和YNd1變壓器接線示意圖Fig.5 Wiring diagram of YNd11 and YNd1 transformer
表5 YNd11與YNd1變壓器繞組對(duì)應(yīng)相位關(guān)系Table 5 Phase relationship between YNd11 and YNd1 transformer winding
利用上文YNd11變壓器與YNd3、YNd7變壓器的高壓側(cè)、低壓側(cè)各相電流相位關(guān)系,結(jié)合表5可分別得到Y(jié)Nd1變壓器與YNd11系列變壓器的高壓側(cè)、低壓側(cè)繞組相位關(guān)系,見(jiàn)表6。
表6 YNd1變壓器與YNd11系列變壓器繞組對(duì)應(yīng)相位關(guān)系Table 6 Phase relationship between YNd1 transformer and YNd11 series transformer winding
由表6可得出YNd3和YNd7接線變壓器差動(dòng)保護(hù)電流相位補(bǔ)償方案,即由YNd3或YNd7變壓器相位補(bǔ)償轉(zhuǎn)換為YNd11變壓器相位補(bǔ)償,再由YNd11變壓器相位補(bǔ)償轉(zhuǎn)換為YNd1變壓器相位補(bǔ)償,通過(guò)這2次硬件相位補(bǔ)償?shù)霓D(zhuǎn)換,將YNd3或YNd7變壓器的差動(dòng)保護(hù)電流相位補(bǔ)償問(wèn)題轉(zhuǎn)變?yōu)榱?點(diǎn)接線的變壓器相位補(bǔ)償,通過(guò)該接線形式的微機(jī)變壓器差動(dòng)保護(hù)裝置軟件相位補(bǔ)償,實(shí)現(xiàn)3點(diǎn)和7點(diǎn)接線情況的相位補(bǔ)償,圖6為具體原理接線示意圖。
圖6 YNd3和 YNd7接線變壓器差動(dòng)保護(hù)電流相位補(bǔ)償原理示意圖Fig.6 Schematic diagram of current phase compensation principle for differential protection of YNd3 and YNd7 connected transformer
同理由上文可得到Y(jié)Nd1、YNd5與YNd9變壓器的高壓側(cè)、低壓側(cè)各相電流相位關(guān)系。結(jié)合表5可分別得到Y(jié)Nd11變壓器與YNd1系列變壓器的高壓側(cè)、低壓側(cè)繞組相位關(guān)系,見(jiàn)表7。
表7 YNd11變壓器與YNd1系列變壓器繞組對(duì)應(yīng)相位關(guān)系Table 7 Phase relationship between YNd11 transformer and YNd1 series transformer winding
由表7可得出YNd5或YNd9接線變壓器差動(dòng)保護(hù)電流相位補(bǔ)償方案。即由YNd5或YNd9變壓器相位補(bǔ)償轉(zhuǎn)換為YNd1變壓器相位補(bǔ)償,再由YNd1變壓器相位補(bǔ)償轉(zhuǎn)換為YNd11變壓器相位補(bǔ)償,通過(guò)這2次硬件相位補(bǔ)償?shù)霓D(zhuǎn)換,將YNd5或YNd9接線變壓器差動(dòng)保護(hù)電流相位補(bǔ)償問(wèn)題轉(zhuǎn)變?yōu)榱?1點(diǎn)接線情況,通過(guò)該接線形式的微機(jī)變壓器差動(dòng)保護(hù)裝置軟件相位補(bǔ)償,實(shí)現(xiàn)5點(diǎn)和9點(diǎn)接線情況的相位補(bǔ)償,圖7為具體原理接線示意圖。
圖7 YNd5和YNd9接線變壓器差動(dòng)保護(hù)電流相位補(bǔ)償原理示意圖Fig.7 Schematic diagram of current phase compensation principle for differential protection of YNd5 and YNd9 connected transformer
YNd系列接線變壓器保護(hù)裝置的三角側(cè)電流回路為星型接線,符合后備保護(hù)對(duì)電流回路星型接法的需要,因此對(duì)實(shí)現(xiàn)被保護(hù)設(shè)備三角側(cè)后備保護(hù)電流測(cè)量無(wú)影響。方案1情況中,其變壓器保護(hù)裝置三角側(cè)電流回路通過(guò)變換相位接入差動(dòng)保護(hù)裝置,此時(shí),變壓器保護(hù)裝置的三角側(cè)各相電流回路與原相電流回路不對(duì)應(yīng),同時(shí)各相電流均為反相接入保護(hù)裝置,在此類(lèi)情況中,方向元件的正確測(cè)量方向及故障錄波的各相電流標(biāo)注均受影響,因此需要通過(guò)轉(zhuǎn)換電流相位,使電流恢復(fù)之前的各相對(duì)應(yīng)關(guān)系。方案2情況中,由于改變接線形式使得YNd系列接線變壓器的星側(cè)和三角側(cè)的各相電流接入YNd1或YNd11微機(jī)變壓器差動(dòng)保護(hù)裝置非原來(lái)的A、B、C或a、b、c各相電流回路,對(duì)后備保護(hù)來(lái)說(shuō),也需要還原原來(lái)相序的電流,才不影響保護(hù)裝置和方向元件的正確測(cè)量[6-8]。
YNd系列接線變壓器差動(dòng)保護(hù)裝置的電流相位補(bǔ)償問(wèn)題,由接入該保護(hù)裝置的相電流2次硬件實(shí)現(xiàn)移相轉(zhuǎn)換, 化簡(jiǎn)歸類(lèi)成YNd1或 YNd11接線情況下的問(wèn)題,因此可利用現(xiàn)有的YNd1或 YNd11接線微機(jī)變壓器差動(dòng)保護(hù)裝置的電流相位補(bǔ)償方案,實(shí)現(xiàn)YNd全系列接線的電流相位補(bǔ)償方案,該方案通過(guò)變壓器差動(dòng)保護(hù)2次硬件補(bǔ)償加常用變壓器差動(dòng)保護(hù)軟件補(bǔ)償共同實(shí)現(xiàn),該方案不需要改動(dòng)現(xiàn)有保護(hù)裝置內(nèi)部的電流相位補(bǔ)償方案,且對(duì)二次回路改動(dòng)小,實(shí)用便捷。