Masu Inganci na Barra da Ilimin Differenshal

Bayanan Tsari na Ikkaddama

Bayanan tsari na ikkaddama shi ne hukuma mai yin haɗaƙarwa da ke taimaka a iya kawo wani abu mai ba da damu a cikin bayanin tsari ta hanyar amfani da kanunin tsari na Kirchoff.

Bayanan Tsari na Ikkaddama

Hukumar bayanan tsari na ikkaddama sun hada da kanunin tsari na Kirchoff, wanda ya ce, duka tsari na gida da ke gudanar da mazauna na jirgin karamin tsari shi daidai da tsari na gida da ke fitar da mazauna. Saboda haka, tsari na gida da ke gudanar da bus section shi daidai da tsari na gida da ke fitar da bus section.

Sassan bayanan tsari na ikkaddama shi ne mai kyau. A wannan, akwai CTs na biyu suke dole. Yana nufin, S1 terminals duka CTs suka dole da sauransu da ke bayyana wire. Duk da cewa, S2 terminals duka CTs suka dole da sauransu don bayyana wire na biyu.A tripping relay ya dogara a tsohon wire biyu.

 A nan, a fayilolin da aka bayyana, na nemi cewa a lokacin da ake da al'amuran, feed, A, B, C, D, E da F suna da tsari IA, IB, IC, ID, IE da IF. Idan kana so ku, a cikin kanunin tsari na Kirchoff,

 Dukkan CTs da ake amfani a cikin bayanan tsari na ikkaddama suna da muhimmanci na tsari. Saboda haka, tsarin duka secondary currents ya zama zero.

 Idan, ka ce tsari a cikin relay da aka dogara a tsohon CTs na biyu, shi ne iR, da iA, iB, iC, iD, iE da iF suna da secondary currents. Idan kana so ku, a node X. A cikin KCL a node X,

 Saboda haka, a lokacin da ake da al'amuran, babu tsari da ke gudanar da busbar protection tripping relay. Wannan relay ana magancewa Relay 87. Idan kana ce abu mai ba da damu ya faru a wata feeders, waje mulkin masu inganta.

A wannan lokaci, tsari mai ba da damu ya faru a primary ya CT ya wata feeders. Wannan tsari mai ba da damu an yi ita da dukkan feeders da suka dogara a cikin bus. Saboda haka, babban baki na tsari mai ba da damu ya faru a CT na wata feeders. Saboda haka a lokacin da ake da abu mai ba da damu, idan kana so ku a node K, za a samu, i R = 0

Wannan na nufin, a lokacin da ake da abu mai ba da damu, babu tsari da ke gudanar da relay 87. Idan kana ce abu mai ba da damu ya faru a cikin bus da kake. A wannan lokaci, babban baki na tsari mai ba da damu an yi ita da dukkan feeders da suka dogara a cikin bus. Saboda haka, a wannan lokaci, tsari duka baki mai ba da damu an yi ita da tsari mai ba da damu.

A wannan lokacin, babu CT a cikin hanyar mai ba da damu. (a lokacin da ake da abu mai ba da damu, tsari mai ba da damu da baki mai ba da damu da ke gudanar da feeders suka dogara a cikin hanyar mai ba da damu).Tsari duka secondary currents ba zama zero. An yi ita da secondary equivalent of faulty current. Idan kana so ku a nodes, za a samu balon da ba zero ba da i R.

 Saboda haka a wannan lokacin, tsari ya faru a cikin relay 87 kuma ya yi trip circuit breaker na dukkan feeders da suka dogara a wata busbar.

Saboda dukkan incoming da outgoing feeders, da suka dogara a wata bus suka yi trip, bus ya zama dead.Wannan hukumar bayanan tsari na ikkaddama suna magancewa current differential protection of busbar.

Bayanan Tsari na Sections

A lokacin da ake bayyana sassan bayanan tsari na ikkaddama, ana bayyana wani busbar da ba da sections. Amma a cikin system da take da tsari mai yawa, electrical bus ya dogara a wajen tsari mai yawa don iyakki masu system.

An yi wannan saboda, abu mai ba da damu a wata section ya kasance wata section. Saboda haka, a lokacin da ake da abu, duk bus ya yi interrupt.Let us draw and discuss about protection of busbar with two sections.

A nan, bus section A ko zone A ya dogara da CT 1, CT2 da CT3 inda CT1 da CT2 su ne feeder CTs da CT3 ne bus CT.

Bayanan Tsari na Voltage

Hukumar bayanan tsari na ikkaddama shi ne mai ma'afuta idan CTs ba su sa ni da saturation kuma suke da muhimmanci na tsari, phase angle error a lokacin da ake da abu mai yawa. Wannan ba shi daidai, musamman, a lokacin da ake da abu mai ba da damu a wata feeders. CT a cikin wata feeders mai ba da damu zai iya satiate da tsari mai yawa kuma za a iya da matsaloli mai yawa. Saboda hakan, tsari duka secondary current of all CTs in a particular zone ba zama zero.

 Saboda haka, akwai adadin yawan da za a iya yi trip dukkan circuit breakers da suka dogara a cikin mulkin inganta. Don haka, 87 relays suka dogara da high pick up current da time delay sai dai sai.Da ma'ana, abin da ya ba da damu da current transformer saturation shi ne transient dc component of the short circuit current.

Wannan abubuwa za a iya karɓar da ita ta hanyar amfani da air core CTs. Wannan current transformer suna magancewa linear coupler. Saboda core na CT ba su da iron, characteristic na secondary su ne straight line. A voltage differential busbar protection, CTs na dukkan incoming da outgoing feeders su dogara a series, ba parallel ba.

Secondary dukkan CTs da differential relay su dogara a closed loop. Idan polarity dukkan CTs su dogara da ma'afuta, tsari duka voltage across all CT secondaries zai zama zero. Saboda haka, babu resultant voltage wace a cikin differential relay. Idan a faru abu a cikin bus, tsari duka CT secondary voltage ba zama zero. Saboda haka, za a faru tsari a cikin loop saboda resultant voltage. 

Saboda hakan, tsari a cikin loop ya faru a cikin differential relay, relay ya yi trip dukkan circuit beaker da suka dogara a cikin protected bus zone. Ba a lokacin da ground fault current ya kasance severely limited by neutral impedance, akwai usually no selectivity problem when such a problem exists, it is solved by use of an additional more sensitive relaying equipment including a supervising protective relay.

Muhimmancin Haɗaƙarwar Masu Inganta

System da yawa sun buƙata da haɗaƙarwar masu inganta don inganta cut-off power interruptions da kuma inganta haɗaƙarwar abu mai ba da damu.