Kananan Gaba da Kuma Yakin Hukuncin Kirkiya na Turbinar

Sararin da kasa da kofin transformer shine abubuwa mafi yawan da suka da shawarar da sararin da kusan da suke bayar. Ana iya cewa masu sayarwa suna neman hanyoyin da za su iya taimakawa wajen samun amfani da kofin da ya fi dace, kuma ana yi nasarorin da za su iya taimaka wajen inganta tsari na kofin da kusan da ita. Idan an rarraba cikin abubuwan da ke kusa da kofin, ana iya cewa masu sayarwa suna neman abin da za su iya taimakawa wajen samun amfani da kofin da ya fi dace, kuma ana yi nasarorin da za su iya taimaka wajen inganta tsari na kofin da kusan da ita. Amma akwai abubuwan da ke faruwa a cikin kofin transformer, musamman idan an yi ground da kofin a matsayin wurare. Wannan takarda yana nuna hanyoyin da za su iya amfani da su don kula da kuma kula da wuraren.

1. Kula da Wuraren Grounding Daban-Daban

1.1 Hukumomin da ya danganta lokacin da ba za a iya kawo transformer da zama

• Idan akwai grounding lead na gaba da kuma karamin wuraren da ya faruwa, za a iya kawo wire da ya haɗa a lokacin da transformer ya yi aiki. Amma ya kamata a duba ta da damar da kafin an saki kofin da ya faruwa.

• Idan wuraren da ya faruwa ba shi ne, za a iya haɗa rheostat (variable resistor) a cikin circuit da ya haɗa don kula da current da ya faruwa zuwa 1 A. An fara kan resistance value ta hanyar kula da voltage da aka samu a cikin normal grounding wire da kuma current da ya faruwa.

• Za a iya amfani da chromatographic analysis don kula da rate na gas generation a wuraren da ya faruwa.

• Ba da amsa da aka samu wuraren da ya faruwa, idan ba a zama da kula da shi, za a iya kawo normal core grounding strap zuwa wurin da wuraren da ya faruwa ya faruwa don kula da circulating currents.

1.2 Hukumomin mai kyau

Idan monitoring ta tabbatar da wuraren da ya faruwa, transformers da za su iya kawo da zama za su iya kawo da zama da kula da shi da kyau. Za a zaba hukumomin mai kyau da za su iya amfani da su don kula da wuraren da ya faruwa. Amma a wasu lokutan, haka bane ya faruwa ba a zama da kula da shi ba. Don kula da wuraren da ya faruwa, za a iya amfani da wasu hukumomin:

• DC Method: Za a iya kawo bonding strap bayan kofin da clamp frame. Za a iya haɗa 6 V DC voltage a cikin silicon steel laminations na biyu a yankin yoke. Sannan za a iya amfani da DC voltmeter don kula da voltage bayan laminations. Littafi da aka samu zero ko da kuma polarity da ya faruwa shine wuraren da ya faruwa.

• AC Method: Za a iya haɗa 220–380 V AC voltage a cikin low-voltage winding, za su iya haɗa magnetic flux a cikin kofin. Ba da amsa da aka kawo core-clamp bonding strap, za a iya amfani da milliammeter don kula da current flow. Za a iya haɗa milliammeter probe bayan laminations, littafi da aka samu zero shine wuraren da ya faruwa.

2. Abubuwan da Wuraren Grounding Daban-Daban Ke Faruwa

• Eddy currents ke faruwa a cikin kofin, wanda ke faruwar core losses da kuma kula da local overheating.

• Idan wuraren da ya faruwa ba a zama da kula da shi, aiki da zama ke faruwar oil da windings, wanda ke faruwar aging da oil-paper insulation. Wannan zai iya faruwar inter-lamination insulation coating da kuma peeling off, wanda ke faruwar overheating da kuma burnout da kofin.

• Wuraren da ya faruwa ke faruwar insulating oil a cikin oil-immersed transformers, wanda ke faruwar flammable gases wanda ke faruwar Buchholz (gas) relay.

• Overheating na kofin ke faruwar wooden blocks da clamp components a cikin tank na transformer.

• Wuraren da ya faruwa ke faruwar grounding conductor, wanda ke faruwar loss of the transformer’s normal single-point grounding—wannan shine halin da ya fi dace da shiga.

• Wuraren da ya faruwa ke faruwar partial discharge phenomena.

3. Dalilin Da Kofin Yana Da Zama Ta Yi Ground Da Matsayin Wurare Da Kawai

A lokacin da aiki, akwai electric field bayan energized windings da transformer tank. Kofin da wasu abubuwan da suka da karo suna cikin wannan field. Saboda distribution da ya faruwa da field strength, idan kofin ba da ground da shi, charge-discharge phenomena ke faruwa, wanda ke faruwar solid da oil insulation. Saboda haka, kofin yana da zama ta yi ground da matsayin wurare da kawai.

Kofin ana haɗa silicon steel laminations. Don kula da eddy currents, har lamination ana haɗa da insulation da kuma small resistance (typically only a few to several tens of ohms). Amma saboda inter-lamination capacitance, laminations ke faruwa conductive path a cikin alternating electric fields. Saboda haka, ground da kofin da matsayin wurare da kawai ne kafin a faruwa entire stack zuwa ground potential.

Idan kofin ko wasu abubuwan da suka da karo suna haɗa da two or more grounding points (grounding daban-daban), za a faruwa closed loop bayan wannan points. Wannan loop ke faruwa electromotive force da kuma circulating currents, wanda ke faruwar local overheating da kuma burnout da kofin.

Single-point grounding of the transformer core ne wanda ke da shawarar da shiga—kofin yana da zama ta yi ground, kuma yana da zama ta yi ground da matsayin wurare da kawai.

Gwargwar gaba suna da shi biyu: (1) tattalin gwamnati mai yawa wanda ke kawo zuwa gudanar da hagu, da (2) abubuwa ko wasu masu sauki suka haifar da zama kan gabashin wurare.