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TOPRAKLAMA A\u011eLARININ \u00dc\u00c7 BOYUTLU TASARIMI \nFikri Bar\u0131\u015f UZUNLAR \nbaris.uzunlar@tr.schneider-electric.com \n \u00d6zcan KALENDERL\u0130 \nozcan@elk.itu.edu.tr \n\u0130stanbul Teknik \u00dcniversitesi, Elektrik-Elektronik Fak\u00fcltesi \nElektrik M\u00fchendisli\u011fi B\u00f6l\u00fcm\u00fc, \u0130stanbul \n\u00d6ZET \nStd \n837-2002 \nstandartlar\u0131na \nBu \u00e7al\u0131\u015fma, IEEE Std 80-2000, IEEE Std 81-1983 ve \nIEEE \nuyumlu \ntopraklama sistemlerinin tasar\u0131m\u0131 ve analizi i\u00e7in bir \nbilgisayar modeli \ngeli\u015fmi\u015f metodoloji \nve \nsunmaktad\u0131r. Metodoloji ve bilgisayar program\u0131 \nger\u00e7ek sistem \u00f6l\u00e7\u00fcmleri ile do\u011frulanm\u0131\u015ft\u0131r. Bilgisayar \nalgoritmas\u0131n\u0131n do\u011frulu\u011fu topraklama modelinin ve \nfiziksel d\u00fczenin ger\u00e7ek saha ko\u015fullar\u0131na ne kadar iyi \nyans\u0131t\u0131ld\u0131\u011f\u0131na ba\u011fl\u0131d\u0131r. \u0130zin verilen gerilim s\u0131n\u0131rlar\u0131 \nve en y\u00fcksek tahmini gerilim de\u011ferleri standartta \nverilen deneysel form\u00fcl kullan\u0131larak hesaplanm\u0131\u015ft\u0131r. \nAd\u0131m, dokunma, a\u011f gerilimleri ve y\u00fcksek gerilimli \nak\u0131m ta\u015f\u0131yan b\u00f6lgeler standartta verilen tavsiyelere \ng\u00f6re hesaplanm\u0131\u015f ve aralar\u0131ndaki \nfarkl\u0131l\u0131klar \nincelenip a\u00e7\u0131klanm\u0131\u015ft\u0131r. M\u00fchendislik uygulamalar\u0131 \ni\u00e7in \ntasar\u0131m \u00f6l\u00e7\u00fctlerinin \ntan\u0131t\u0131lmas\u0131 olana\u011f\u0131n\u0131n ger\u00e7ekle\u015ftirilmesi amac\u0131yla \nbenzetimler yap\u0131lm\u0131\u015ft\u0131r. Kolay kullan\u0131m \u00fcst\u00fcnl\u00fc\u011f\u00fc ve \nyerle\u015fik tehlikeli nokta de\u011ferlendirme olana\u011f\u0131yla her \n\u015fekildeki mevcut a\u011flar\u0131n g\u00fc\u00e7lendirilmesi ve yeni \na\u011flar\u0131n tasar\u0131m\u0131n\u0131n en uygun hale getirilmesinde \nm\u00fchendislere yard\u0131m etmek i\u00e7in tesis topraklama a\u011f \ntasar\u0131m ve analiz mod\u00fcl\u00fc \u00f6zellikle tasarlanm\u0131\u015ft\u0131r. \nyararl\u0131 baz\u0131 pratik \nAnahtar s\u00f6zc\u00fckler: Topraklama a\u011f\u0131, Dokunma \nGerilimi, Ad\u0131m Gerilimi, A\u011f Gerilimi. \n1. G\u0130R\u0130\u015e \ntransformat\u00f6r merkezlerinde \nTopraklama a\u011flar\u0131, toprak i\u00e7ine g\u00f6m\u00fclm\u00fc\u015f , toprak \ny\u00fczeyine paralel olarak yerle\u015ftirilmi\u015f, a\u011f olu\u015fturacak \n\u015fekilde birbirine birle\u015ftirilmi\u015f iletkenlerden olu\u015fan, \ngeni\u015f bir alan\u0131 kaplayan bir topraklay\u0131c\u0131 t\u00fcr\u00fcd\u00fcr. Enerji \nve \nsistemlerinde, \npotansiyel farklar\u0131n\u0131n k\u00fc\u00e7\u00fck olmas\u0131 istenen geni\u015f \nyap\u0131larda ve yerlerde, topraklama direncini, ad\u0131m ve \ntemas gerilimini k\u00fc\u00e7\u00fck tutmak ve d\u00fczg\u00fcn potansiyel \nda\u011f\u0131l\u0131m\u0131 sa\u011flamak amac\u0131 ile kullan\u0131l\u0131rlar. Topraklama \na\u011flar\u0131n\u0131n bu ama\u00e7lara uygun ve ekonomik tasar\u0131m\u0131 ve \nanalizi, bir m\u00fchendislik problemi olu\u015fturmaktad\u0131r. \ntasar\u0131m hesaplar\u0131, genellikle \nTopraklama a\u011flar\u0131n\u0131n \ndeneyime, \nform\u00fcller \n(ampirik) \ndayal\u0131 \ng\u00f6rg\u00fcye \nkullan\u0131larak yap\u0131lmaktad\u0131r. Bu hesaplar, \u00fc\u00e7 boyutlu \ntopraklay\u0131c\u0131 ko\u015fullar\u0131n\u0131 \nincelemede, \ntoprak \nve \nbir\u00e7ok \ntan\u0131mlamada ve ger\u00e7e\u011fe uygun \u00e7\u00f6z\u00fcmler elde etmede \nyetersiz kalmakta, zor ve zaman al\u0131c\u0131 olmaktad\u0131r. \nBir topraklama a\u011f\u0131n\u0131n tasar\u0131m\u0131nda a\u011f boyutlar\u0131 ve \nbi\u00e7imi, g\u00f6z say\u0131s\u0131, g\u00f6m\u00fclme derinli\u011fi, topra\u011f\u0131n \u00f6zellikleri \ngibi \nde\u011ferlendirilmesi \nparametrenin \ngerekmektedir. Bunu ger\u00e7ek bir topraklama a\u011f\u0131 \u00fczerinde \ndeney yaparak ger\u00e7ekle\u015ftirmek hem zor hem de zaman \nal\u0131c\u0131 ve pahal\u0131 bir yoldur. Bunun kolay, k\u0131sa ve \nekonomik yolu, \u00f6rne\u011fin, \u00f6l\u00e7ekli k\u00fc\u00e7\u00fck modeller \n\u00fczerinde deney yapmak veya say\u0131sal y\u00f6ntemlerle \nbilgisayarda ger\u00e7e\u011fe uygun modeller \u00fczerinde hesap \nyapmakt\u0131r. Bu nedenle son y\u0131llarda topraklama a\u011flar\u0131n\u0131n \ntasar\u0131m ve analizinin bilgisayarla yap\u0131lmas\u0131 g\u00f6zdedir. \nBunun i\u00e7in de topraklama sistemlerinin tasar\u0131m\u0131nda \nger\u00e7e\u011fe uygun, daha do\u011fru sonu\u00e7lar veren bilgisayar \nalgoritmalar\u0131na gerek duyulmaktad\u0131r. Bu ama\u00e7la y\u00f6ntem \nve yaz\u0131l\u0131m geli\u015ftirme \u00e7al\u0131\u015fmalar\u0131 yap\u0131lmakta, paket \nprogramlar \u00fcretilmektedir. \nBu \u00e7al\u0131\u015fmada da, ilkesi sonlu elemanlar y\u00f6ntemine \ndayanan bir topraklama a\u011f\u0131 tasar\u0131m program\u0131 yard\u0131m\u0131yla \nyap\u0131lan \u00fc\u00e7 boyutlu a\u011f \ntasar\u0131m\u0131, a\u00e7\u0131klamal\u0131 ve \nuygulamal\u0131 olarak sunulmu\u015ftur. \n2. AMA\u00c7 VE HEDEFLER \nBu \u00e7al\u0131\u015fmadaki temel ama\u00e7lar: \n- Topraklama \nsistemi \ntasar\u0131mc\u0131lar\u0131n\u0131n en verimli \ntasar\u0131ma odaklanabilmeleri i\u00e7in gerekli ilkeleri i\u00e7eren \nuygun bir referans sa\u011flamak, \n- Dokunma ve ad\u0131m gerilimlerini izin verilen g\u00fcvenlik \ns\u0131n\u0131rlar\u0131 i\u00e7erisinde tutmak ve topraklama direncini \nk\u00fc\u00e7\u00fcltmek, \n- IEEE Std 80-2000 [1], IEEE Std 81-1983 [2] ve IEEE \nStd 837-2002 [3] standartlar\u0131na uygun bir topraklama \ntesisi tasarlamak, \n- Ar\u0131za durumlar\u0131nda elektrik \u015fokuna maruz kalma \nolas\u0131l\u0131\u011f\u0131 bulunan personelin g\u00fcvenli\u011fini sa\u011flamak, \n- Topraklama sisteminde kullan\u0131lmas\u0131 gereken a\u011f \niletkenlerinin \u00f6zelliklerini belirlemek, \n- Tesis alan\u0131, \ntopraklama kaz\u0131klar\u0131n\u0131n say\u0131s\u0131, a\u011f \niletkeninin kesiti ve iletkenin g\u00f6m\u00fclme derinli\u011fi gibi \netkenlerin \ndirencinin \nhesaplanmas\u0131nda etkisini g\u00f6zlemlemek, \ntopraklama \ntesisin \n- Toprak gerilim y\u00fckselmesini (GPR) hesaplamak, \n- \u0130zin verilen en y\u00fcksek dokunma ve ad\u0131m gerilimlerini \nhesaplamak, \n307 \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n\f- Herhangi bir y\u00f6n boyuncaki y\u00fczey gerilim da\u011f\u0131l\u0131m\u0131n\u0131 \ntoprak gerilimi y\u00fckselmesinin bir oran\u0131 olarak \ng\u00f6r\u00fcnt\u00fclemek, \n- T\u00fcm tasar\u0131m ayr\u0131nt\u0131lar\u0131n\u0131 i\u00e7eren bir rapor sunmakt\u0131r. \n3. TOPRAKLAMA A\u011eI TASARIM \nYAZILIMI \nTopraklama sistemlerinin modellenmesinde kullan\u0131lan \nbilgisayar algoritmalar\u0131nda a\u015fa\u011f\u0131daki \u00f6zellikler aran\u0131r: \n- Topraklama iletkeni ve topraklama kaz\u0131klar\u0131n\u0131n ayr\u0131 \nbirer eleman olarak modellenebilmesi, \n- Her ayr\u0131 eleman\u0131n bir denklem k\u00fcmesi olarak \ntan\u0131mlanabilmesi, \n- Topra\u011fa akan toprak ar\u0131za ak\u0131m\u0131n\u0131n hesaplanmas\u0131, \n- \u0130stenen herhangi bir noktada, y\u00fczey potansiyelinin \nhesaplanmas\u0131 istenir. \ntan\u0131mlanmal\u0131d\u0131r. \nTopraklama tasar\u0131m\u0131n\u0131n ger\u00e7ekle\u015ftirilmesinde ilk olarak \nproje ve \u00e7al\u0131\u015fma \n\u0130kinci olarak, \nkullan\u0131lacak \ntoprak modeli kararla\u015ft\u0131r\u0131lmal\u0131d\u0131r. Bu \na\u015famada IEEE Std 80-2000\u2019de tan\u0131mlanm\u0131\u015f, belirli bir \ny\u00fczey ve durum i\u00e7in izin verilen en y\u00fcksek ad\u0131m ve \ndokunma gerilimini i\u00e7eren g\u00fcvenlik de\u011ferlendirmesi \nise, bir elektrik \nhesab\u0131 yap\u0131l\u0131r. \u00dc\u00e7\u00fcnc\u00fc a\u015famada \nar\u0131za \nen k\u00f6t\u00fc \ntesisinde meydana gelebilecek \nparametreleri hesaba kat\u0131larak iletkenlerin ve kaz\u0131k gibi \nelektrotlar\u0131n boyutlar\u0131 kararla\u015ft\u0131r\u0131lmaktad\u0131r. Bir sonraki \na\u015famada, elektrik \niletkenin \ng\u00f6m\u00fclme derinli\u011fi ve fiziksel boyutlar\u0131 gibi sahan\u0131n \ngeometrik boyut ve bi\u00e7im bilgileri girilmektedir. Son \nolarak, tesis tasar\u0131m\u0131n\u0131n istenilen g\u00fcvenlik \u00f6l\u00e7\u00fctlerini \nkar\u015f\u0131lay\u0131p kar\u015f\u0131lamad\u0131\u011f\u0131 do\u011frulanmaktad\u0131r. Potansiyel \nda\u011f\u0131l\u0131m\u0131 \u00e7izimi, dokunma ve ad\u0131m gerilimlerinin \nolu\u015fturulmal\u0131d\u0131r. \na\u015f\u0131lmad\u0131\u011f\u0131n\u0131 \nG\u00fcvenlik \u00f6l\u00e7\u00fctleri sa\u011flanmad\u0131\u011f\u0131nda, a\u011f tasar\u0131m\u0131n\u0131n \nyeniden g\u00f6zden ge\u00e7irilmesi gerekir. Kabul edilebilir \nsonu\u00e7lar elde edilene kadar y\u00f6ntem \u00fc\u00e7\u00fcnc\u00fc a\u015famadan \ntekrarlan\u0131r. Bu \u00e7al\u0131\u015fmada kullan\u0131lan yaz\u0131l\u0131m a\u015fa\u011f\u0131daki \u00fc\u00e7 \nana mod\u00fclden olu\u015fmaktad\u0131r: \ntesisinin koordinatlar\u0131, \ndo\u011frulamak \n\u00fczere \n\u015eekil 1. Toprak analiz mod\u00fcl\u00fc \n1) Toprak modeli (bir tabakal\u0131 veya \u00e7ok tabakal\u0131), \n2) \u00dcst tabaka kal\u0131nl\u0131\u011f\u0131 (m), \n3) \u00dcst tabaka \u00f6zdirenci (ohm.m), \n4) Alt tabaka kal\u0131nl\u0131\u011f\u0131 (m), \n5) Alt tabaka \u00f6zdirenci (ohm.m), \n6) Ar\u0131za s\u00fcresi (s), \n7) V\u00fccut a\u011f\u0131rl\u0131\u011f\u0131 (kg). \nB. Toprak lama A\u011f\u0131 Analiz Mod\u00fcl\u00fc \nSahan\u0131n elektriksel karakteristiklerinin ve kullan\u0131lacak \na\u011f iletkenlerinin \u00f6zelliklerinin bulundu\u011fu mod\u00fcld\u00fcr \n(\u015eekil 2). Bu mod\u00fclden a\u015fa\u011f\u0131daki bilgiler girilir: \n1) Tesis i\u015fletme gerilimi (V), \n2) Toprak ar\u0131za ak\u0131m\u0131 (A), \n3) Topraklama kaz\u0131k ve iletkenin adet ve \nuzunluklar\u0131, \n4) Toprak gerilim y\u00fckselmesi (GPR) (V), \n5) Hesaplanan toprak direnci (ohm), \n6) E\u015fde\u011fer empedans (ohm). \nA. Toprak Analiz Mod\u00fcl\u00fc \nBu mod\u00fclde benzetimi yap\u0131lacak sahan\u0131n topraklama \ntasar\u0131m\u0131 \ni\u00e7in gerekli, a\u015fa\u011f\u0131daki parametreler yer \nalmaktad\u0131r (\u015eekil 1): \n\u015eekil 2. Topraklama a\u011f\u0131 analiz mod\u00fcl\u00fc \nC. \u00dc\u00e7 Boyutlu Potansiyel Da\u011f\u0131l\u0131m\u0131 Mod\u00fcl\u00fc \nBu mod\u00fclde de, sonlu elemanlar y\u00f6ntemiyle benzetim \nsonucu bulunan potansiyel da\u011f\u0131l\u0131m\u0131 \u00fc\u00e7 boyutlu olarak \ng\u00f6zlenebilmektedir (\u015eekil 3). \n308 \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n\fE\u011fer a >> b ise (1) ba\u011f\u0131nt\u0131s\u0131ndan \n(2) \nyaz\u0131l\u0131r. \u0130zin verilen en y\u00fcksek dokunma ve ad\u0131m \ngerilimleri IEEE Std 80-2000 standard\u0131na uygun olarak \nhesaplan\u0131r. Hesaplaman\u0131n amac\u0131, y\u00fcksek diren\u00e7li y\u00fczey \nkatman\u0131 kullan\u0131l\u0131p b\u00f6ylece \nizin verilen dokunma \ngerilimini de y\u00fcksek tutmakt\u0131r. Hesaplarda kullan\u0131lan \ny\u00fczey tabakas\u0131n\u0131n azaltma katsay\u0131s\u0131 (Cs) a\u015fa\u011f\u0131daki \nform\u00fcl ile hesaplan\u0131r: \n (3) \nV\u00fccut a\u011f\u0131rl\u0131\u011f\u0131n\u0131n 50 kg olmas\u0131 durumunda, s\u0131ras\u0131yla, \ndokunma ve ad\u0131m gerilimleri: \n (4) \n(5) \nV\u00fccut a\u011f\u0131rl\u0131\u011f\u0131n\u0131n 70 kg olmas\u0131 durumundaki dokunma \nve ad\u0131m gerilimleri: \n (6) \n(7) \nYukar\u0131daki ba\u011f\u0131nt\u0131larda kullan\u0131lan parametrelerden: \n\u2022 ts saniye olarak \u015fok s\u00fcresini, \n\u2022 \ns ohm-metre olarak topra\u011f\u0131n y\u00fczey k\u0131sm\u0131ndaki \nmalzemenin \u00f6zdirencini, \n\u2022 Cs y\u00fcksek diren\u00e7li y\u00fczey malzemesi kullan\u0131m\u0131na ve \nyans\u0131ma fakt\u00f6r\u00fc (K) ile \u00fcst katman\u0131n kal\u0131nl\u0131\u011f\u0131na (h) \nba\u011fl\u0131 azaltma katsay\u0131s\u0131n\u0131, \n\u2022 hs y\u00fcksek diren\u00e7li y\u00fczey malzemesinin kal\u0131nl\u0131\u011f\u0131n\u0131, \n\u2022 \n y\u00fcksek diren\u00e7li y\u00fczey malzemesinin alt\u0131ndaki \ntopra\u011f\u0131n \u00f6zdirencini \nifade etmektedir. \n5. BENZET\u0130MLER \nBu \u00e7al\u0131\u015fmada elde edilen sonu\u00e7lar\u0131n do\u011frulanmas\u0131 \nad\u0131na IEEE Std 80-2000 standard\u0131n\u0131n Ek B k\u0131sm\u0131nda \nverilmi\u015f olan \u00f6rnekler referans al\u0131nm\u0131\u015f ve kar\u015f\u0131la\u015ft\u0131rmal\u0131 \ntablolar ile ilgili grafikler kullan\u0131lm\u0131\u015ft\u0131r. Tasar\u0131m bilgileri \nTablo 1\u2019de verilmi\u015ftir. \nTablo 1: A\u011f tasar\u0131m\u0131nda kullan\u0131lan tasar\u0131m bilgileri \n\u00d6zellik \nDe\u011fer \n\u015eekil 3. \u00dc\u00e7 boyutlu potansiyel da\u011f\u0131l\u0131m\u0131 mod\u00fcl\u00fc \n4. TOPRAKLAMA A\u011eI TASARIM \nY\u00d6NTEM\u0130 \nPratikteki toprak modellerine ula\u015fabilmek i\u00e7in y\u0131llard\u0131r \nbir\u00e7ok grafiksel ve analitik yakla\u015f\u0131mlar \u00f6nerilmi\u015ftir [4-8, \n10]. De\u011fi\u015fik toprak \u00f6zdiren\u00e7li katmanlardan olu\u015fan \u00e7ok \ntabakal\u0131 topraklar\u0131n daha yayg\u0131n olmas\u0131ndan dolay\u0131, \ntopraklama direnci \u00f6l\u00e7\u00fcm teknikleri \u00e7ok katmanl\u0131 toprak \nmodeline g\u00f6re kullan\u0131lmaktad\u0131r. \nTesis topraklamas\u0131n\u0131n pratik yakla\u015f\u0131m\u0131nda y\u0131llard\u0131r, \nsonsuz derinlik ve farkl\u0131 diren\u00e7te alt katman ile sonlu \nderinlikte \u00fcst katmandan olu\u015fan iki tabakal\u0131 model \nkullan\u0131lm\u0131\u015ft\u0131r. Yaz\u0131l\u0131m [9] her kaz\u0131k \u00e7iftinin aras\u0131ndaki \nmesafenin (a) e\u015fit oldu\u011fu Wenner d\u00f6rt kaz\u0131kl\u0131 toprak \n\u00f6zdirenci \u00f6l\u00e7\u00fcm tekni\u011fini desteklemektedir (\u015eekil 4). Bu \ny\u00f6nteme g\u00f6re, d\u0131\u015ftaki elektrotlardan, de\u011feri ampermetre \nile \u00f6l\u00e7\u00fclen I ak\u0131m\u0131 uygulan\u0131rken, i\u00e7teki elektrotlar \naras\u0131nda, uygulanan ak\u0131m\u0131n \ntopra\u011f\u0131n direncinde \nyaratt\u0131\u011f\u0131 V gerilimi voltmetreyle \u00f6l\u00e7\u00fcl\u00fcr ve direnci \nbulmak i\u00e7in ohm yasas\u0131 uygulan\u0131r (R = V \/ I). \n\u015eekil 4. Wenner d\u00f6rt kaz\u0131k y\u00f6ntemi \n\u00d6l\u00e7\u00fclen V ve I de\u011ferlerine, topraklama kaz\u0131\u011f\u0131n\u0131n \nboyuna (b) ve kaz\u0131klar aras\u0131 uzakl\u0131\u011fa (a) g\u00f6re toprak \n\u00f6zdirenci ( ) a\u015fa\u011f\u0131daki ba\u011f\u0131nt\u0131yla bulunur: \n(1) \n309 \n2222421)\/(4baabaaIVa)\/(2IVa0,09(1\/)120,09sssCh50(10001,5)0,116\/dokunmasssECt50(10006,0)0,116\/sad\u0131mssECt70(10001,5)0,157\/dokunmasssECt70(10006,0)0,157\/sad\u0131mssECt \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n\fV\u00fccut a\u011f\u0131rl\u0131\u011f\u0131 \n\u00c7ak\u0131l ta\u015f\u0131n\u0131n \u00f6zdirenci \n\u00c7ak\u0131l ta\u015f\u0131 tabakas\u0131n\u0131n kal\u0131nl\u0131\u011f\u0131 \nAr\u0131za a\u00e7ma s\u00fcresi \nToprak \u00f6zdirenci \nEn y\u00fcksek ar\u0131za ak\u0131m\u0131 IG, \nX\/R oran\u0131 \nAr\u0131za ak\u0131m\u0131 IG \nAyr\u0131lma katsay\u0131s\u0131 Sf \n\u0130letkenin malzemesi \nOrtam s\u0131cakl\u0131\u011f\u0131 \nA\u011f iletkeninin \u00e7ap\u0131 \nA\u011f\u0131n g\u00f6m\u00fclme derinli\u011fi \n70 kg \n2500 \u03a9.m \n0,102 m \n0,50 s \n400 \u03a9.m \n6814 A, 16,2 \n3180 A \n0,6 \nSert \u00e7ekilmi\u015f bak\u0131r \n40 C \n0,01 m \n0,5 m \nD. Topraklama kaz\u0131klar\u0131 olmayan kare a\u011f \n\u015eekil 5\u2019te topraklama kaz\u0131klar\u0131 olmayan, 70 m x 70 m \nboyutlar\u0131nda, 9 x 9 g\u00f6zden olu\u015fan kare bir a\u011f\u0131n \u00fc\u00e7 \nboyutlu \u00e7izimi g\u00f6r\u00fclmektedir. Tablo 2\u2019de hem IEEE Std \n80-2000 ile hem de bu \u00e7al\u0131\u015fmada kullan\u0131lan yaz\u0131l\u0131m ile \nelde edilen sonu\u00e7lar kar\u015f\u0131la\u015ft\u0131rma amac\u0131yla bir arada \nverilmi\u015ftir. \n\u015eekil 6. Topraklama kaz\u0131klar\u0131 olmayan kare a\u011f i\u00e7in \nen y\u00fcksek ve ger\u00e7ek dokunma gerilimleri \nE. Topraklama kaz\u0131kl\u0131 dikd\u00f6rtgen a\u011f \n\u015eekil 7\u2019de topraklama kaz\u0131kl\u0131, 63 m x 84 m boyutlar\u0131nda, \n9 x 12 g\u00f6zden olu\u015fan dikd\u00f6rtgen bir a\u011f\u0131n \u00fc\u00e7 boyutlu \n\u00e7izimi g\u00f6r\u00fclmektedir. \n\u015eekil 7\u2019deki a\u011f i\u00e7in her iki y\u00f6ntemle de elde edilen \nsonu\u00e7lar Tablo 3\u2019te verilmi\u015ftir. \n\u015eekil 5. Topraklama kaz\u0131klar\u0131 olmayan kare a\u011f \nTablo 2: Topraklama kaz\u0131klar\u0131 olmayan kare a\u011f i\u00e7in \nkar\u015f\u0131la\u015ft\u0131rmal\u0131 sonu\u00e7lar tablosu \n\u00d6zellik \n\u0130zin verilen en y\u00fcksek \ndokunma gerilimi (V) \n\u0130zin verilen en y\u00fcksek ad\u0131m \ngerilimi (V) \nAzaltma katsay\u0131s\u0131 CS \nRG (\n) \nGPR (V) \nIEEE Std \n80-2000 \n838,20 \nYaz\u0131l\u0131m \n840,55 \n2686 \n2696,10 \n0,740 \n2,780 \n5304,00 \n0,740 \n2,675 \n5105,61 \nKaz\u0131ks\u0131z, kare a\u011f i\u00e7in elde edilen \u015eekil 6\u2019daki potansiyel \nda\u011f\u0131l\u0131m\u0131ndan, \nsisteminin k\u00f6\u015felerinde \ndokunma geriliminin maksimum de\u011ferinin a\u015f\u0131ld\u0131\u011f\u0131n\u0131 \ng\u00f6zlemlemek m\u00fcmk\u00fcnd\u00fcr. \ntopraklama \n\u015eekil 7. Topraklama kaz\u0131kl\u0131 dikd\u00f6rtgen a\u011f \nTablo 3: Topraklama kaz\u0131kl\u0131 dikd\u00f6rtgen a\u011f i\u00e7in \nkar\u015f\u0131la\u015ft\u0131rmal\u0131 sonu\u00e7lar tablosu \n\u00d6zellik \n\u0130zin verilen en y\u00fcksek \ndokunma gerilimi (V) \n\u0130zin verilen en y\u00fcksek \nad\u0131m gerilimi (V) \nAzaltma katsay\u0131s\u0131 CS \n) \nRG (\nGPR (V) \nIEEE Std \n80-2000 \n838,20 \nYaz\u0131l\u0131m \n840,55 \n2686 \n2696,10 \n0,740 \n2,620 \n4998,96 \n0,740 \n2,278 \n4348,00 \n\u015eekil 7\u2019deki a\u011f i\u00e7in, kullan\u0131lan yaz\u0131l\u0131m ile elde edilen \npotansiyel da\u011f\u0131l\u0131m\u0131, \u015eekil 8\u2019de g\u00f6sterilmi\u015ftir. Yine \nk\u00f6\u015felerde potansiyel art\u0131\u015f\u0131 g\u00f6zlemlenmektedir. \n310 \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n\fTablo 5: E\u015fit aral\u0131klarla yerle\u015ftirilmi\u015f topraklama kaz\u0131kl\u0131 \nve iki tabakal\u0131 a\u011f i\u00e7in kar\u015f\u0131la\u015ft\u0131rma tablosu \n\u00d6zellik \n\u0130zin verilen en y\u00fcksek \ndokunma gerilimi (V) \n\u0130zin verilen en y\u00fcksek \nad\u0131m gerilimi (V) \nAzaltma katsay\u0131s\u0131 CS \nRG (\n) \nGPR (V) \nIEEE Std \n80-2000 \n838,20 \nYaz\u0131l\u0131m \n840,55 \n2686 \n2696,10 \n0,740 \n2,740 \n4562,49 \n0,740 \n2,330 \n5227,92 \nBu durumdan da g\u00f6zlenebilece\u011fi \u00fczere, topraklama \ndirenci d\u00fc\u015f\u00fck olarak elde edildik\u00e7e sonu\u00e7lar aras\u0131ndaki \nfark neredeyse \u00f6nemsizdir. \u015eekil 9\u2019daki a\u011f \ni\u00e7in, \nkullan\u0131lan yaz\u0131l\u0131m ile elde edilen potansiyel da\u011f\u0131l\u0131m\u0131, \n\u015eekil 10\u2019daki gibi g\u00f6zlemlenmektedir. \n6. SONU\u00c7 \nBilgisayar benzetimine dayal\u0131 analiz teknikleri hen\u00fcz \npahal\u0131 olmakla birlikte bunlar\u0131n kullan\u0131m\u0131n\u0131n ucuz ve \ntopraklama \u015febekesi d\u00fczenlenmesine yol \ng\u00fcvenli \na\u00e7aca\u011f\u0131 a\u00e7\u0131kt\u0131r. Yap\u0131lan parametrik analizlerin \u00e7ok \ntabakal\u0131 \ni\u00e7erecek bi\u00e7imde \nyenilenmesi gerekmektedir. Topraklama \u015febekesini \nd\u00fczenleyen standartlar aras\u0131nda uyumlula\u015ft\u0131rmaya \nihtiya\u00e7 vard\u0131r. \ntoprak ko\u015fullar\u0131n\u0131 da \n\u015eekil 8. Topraklama kaz\u0131kl\u0131 dikd\u00f6rtgen a\u011f i\u00e7in en \ny\u00fcksek ve ger\u00e7ek dokunma gerilimleri \nF. E\u015fit aral\u0131klarla yerle\u015ftirilmi\u015f topraklama kaz\u0131kl\u0131 \nve iki tabakal\u0131 a\u011f \nPratikte bir\u00e7ok uygulamada kullan\u0131lan iki tabakal\u0131 \ntopraklama sistemlerinin benzetimlerini \u00f6rneklemek \namac\u0131yla, IEEE Std 80 standard\u0131n\u0131n B.5 \u00f6rne\u011finde, \nTablo 4\u2019deki bilgilerle, \u015eekil 9\u2019da g\u00f6sterilen 60,96 m x \n60,96 m boyutlar\u0131nda, 4 x 4 g\u00f6zl\u00fc benzetim \nyap\u0131lmaktad\u0131r. \u015eekil 9\u2019daki a\u011f i\u00e7in her iki y\u00f6ntemle de \nelde edilen sonu\u00e7lar Tablo 5\u2019te verilmi\u015ftir. \nTablo 4: \u0130ki tabakal\u0131 a\u011f tasar\u0131m\u0131nda kullan\u0131lan bilgiler \n\u00d6zellik \nV\u00fccut a\u011f\u0131rl\u0131\u011f\u0131 \n\u00c7ak\u0131l ta\u015f\u0131n\u0131n \u00f6zdirenci \n\u00c7ak\u0131l tabakas\u0131n\u0131n kal\u0131nl\u0131\u011f\u0131 \n\u00dcst tabakan\u0131n \u00f6zdirenci \n\u00dcst tabakan\u0131n kal\u0131nl\u0131\u011f\u0131 \nAlt tabakan\u0131n \u00f6zdirenci \nA\u011f iletkeninin \u00e7ap\u0131 \nA\u011f\u0131n g\u00f6m\u00fclme derinli\u011fi \nKaz\u0131klar\u0131n uzunlu\u011fu \nKaz\u0131k \u00e7ap\u0131 \nAr\u0131za a\u00e7ma s\u00fcresi \nToprak \u00f6zdirenci \nAr\u0131za ak\u0131m\u0131 IG \nDe\u011fer \n70 kg \n2500 \u03a9.m \n0,1 m \n300 \u03a9.m \n4,572 m \n100 \u03a9.m \n0,01 m \n0,5 m \n9,144 m \n0,0127 m \n0,50 s \n400 \u03a9.m \n1908 A \n\u015eekil 10. Topraklama kaz\u0131kl\u0131 dikd\u00f6rtgen a\u011f i\u00e7in en \ny\u00fcksek ve ger\u00e7ek dokunma gerilimleri \nKAYNAKLAR \n[1] IEEE Std. 80-2000, IEEE Guide for Safety in AC \nSubstation Grounding, IEEE Standard Board, New \nYork, USA, 2000. \n[2] IEEE Std. 81-1983, IEEE Guide for Measuring Earth \nResistivity, Ground Impedance and Earth Surface \nPotentials of a Ground System, IEEE Standard \nBoard, New York, USA, 1983. \n[3] IEEE Std. 837, IEEE Standard for Qualifying \nin Substation \nPermanent Connections Used \n311 \n\u015eekil 9. E\u015fit aral\u0131klarla yerle\u015ftirilmi\u015f topraklama \nkaz\u0131kl\u0131 ve iki tabakal\u0131 a\u011f \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n\fGrounding, IEEE Standard Board, New York, USA, \n2002. \n[4] C. H. Lee, A. P. S. Meliopoulos, \"Comparison of \ntouch and step voltages between IEEE Std. 80 and \nIEC 479-1\", IEE Proceedings on Generation, \nTransmission and Distribution, Vol. 146, No. 6, pp. \n593\u2013601, 1999. \n[5] H. Zhao, H. Griffiths, A. Haddad, A. Ainsley, \n\"Safety-limit curves for earthing system designs: \nappraisal of standard recommendations \", IEE \nProceedings on Generation, Transmission and \nDistribution, Vol. 152, No. 6, pp. 871\u2013879, 2005. \n[6] M. H. Hocao\u011flu, A. T. Hocao\u011flu, \"Y\u00fcksek gerilim \nstandartlar\u0131n\u0131n \ntesisleri \nkar\u015f\u0131la\u015ft\u0131r\u0131lmas\u0131\", Elektrik, Elektronik, Bilgisayar \nM\u00fchendisli\u011fi 8. Ulusal Kongresi, Gaziantep, s. 395-\n398, 1999. \ntopraklama \n[7] L. M. Coa, \"Comparative study between IEEE Std. \n80-2000 and finite elements method application for \ngrounding systems analysis\", Transmission & \nDistribution Conference and Exposition, Latin \nAmerica, pp. 1-5, 2006. \n[8] J. Ma, F. P. Dawalibi, R. D. Southey, \"Effects of the \nchanges in IEEE Std. 80 on the design and \nanalysis of power system grounding\", PowerCon \nInternational Conference, Vol. 2, 974-979, 2002. \n[9] CYMGRD, User Guide and Reference Manual, \nCanada, 2006. \n[10] S. Meliopoulos, Power System Grounding and \nTransients, Marcel Dekker, New York, 1998. \n312 \n \n \n\f<\/pre>\n
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