110 kV Turanci Maimaitaccen Haraji Aikin Yamma: ATP Tashin Hadari da Kayan Aiki na IEE-Business

Akwai littattafan da dama game da bincike da aka yi a kan overvoltage a maimakon transformer a lokacin da cutar sama ya faru. Amma, saboda hanyoyi da kawo-kawoyi na cutar sama, bayanin tarihi mai zurfi ba shi da za a iya bayyana. A cikin tattalin inganci, an samun hakurarin sauyin da suka fi sani da wurare masu sauki don cutar sama, ta haka ana samun abubuwa masu sauki da suke takarda.

Shugaban kasa ko lalace suna da kyau a gudanar da cutar sama. Cutar sama zai iya haɗa a tsakanin shugaban kasa zuwa lalace ko a gudanar da aiki a lalace, wanda yake saukar da overvoltage a maimakon transformer, wanda yana nuna hadin sarrafa insulation a maimakon. Saboda haka, binciken da take daidaita game da siffofin overvoltage a maimakon a lokacin cutar sama da kuma tattaunan da ake samar da suka fi sani da voltage-limiting devices yana da muhimmanci [1]. Wannan rubutu na nuna binciken da aka yi a kan Alternative Transients Program (ATP), babban version na Electromagnetic Transients Program (EMTP), da ita ce ta yi a kan sakamakon 110 kV lalace. Tattaunan da suka samar da theory da ke rage da overvoltage a lokacin cutar sama da kuma siffofin insulation a maimakon 110 kV transformer, an yi amfani da su don rarrabe overvoltage a maimakon a wasu hali na cutar sama. An yi tattaunawa a kan abubuwan da aka samu, da kuma an bayyana hanyoyin da za su iya yin don kammala overvoltage a maimakon.

1. Binciken Tarihi

1.1 Gudanar da Cutar Sama a Shugaban Kasa

Idan shugaban kasa na gida an gudanar da cutar sama, akwai traveling wave wanda yake haɗa a kan conductor [1]. A cikin lalace, akwai manya connecting lines (misali, connections daga transformers zuwa busbars ko surge arresters) wadanda suke aiki da shugaban kasa a lokacin da cutar sama yana faru. Dukkan line-olin suna da kyau a gudanar da cutar sama, suke haɗa, suka gudanar da kuma suka faɗa, wanda yake saukar da transient overvoltages da masu peak amplitudes masu yawan da za su iya juye aiki.

1.2 Binciken Parameter Game da Y-Connected Transformer Windings a Lokacin Cutar Sama

Transformer windings na uku suka fi sani da Y, Yo, ko Δ configurations. A lokacin da suke yi aiki, cutar sama zai iya haɗa a kan one, two, ko kuma uku phases [1]. Wannan rubutu na nuna Y-connected windings, domin kawai wadannan configurations ne da maimakon da ake iya tabbatar da shi. Idan transformer an samar da Yo da kuma mutual coupling daga phase to phase an kara, idan one, two, ko kuma uku phases an gudanar da cutar sama, za a iya bincika system a matsayin three independent windings da terminals masu ground.

2. Haliyar Insulation a Maimakon 110 kV Transformer

Maimakon 110 kV transformers suna da graded insulation, wanda aka taurari a matsayin 35 kV, 44 kV, ko 60 kV levels. Yanzu, producers suna samun transformers da 60 kV neutral-point insulation. Level-olin masu insulation suna da cikakken dielectric withstand capabilities, kamar yadda aka nuna a Table 1. Saboda haliyar practical, insulation aging, da kuma safety margins for power-frequency voltage, an yi amfani da correction factors. Lightning impulse withstand margin factor da 0.6 da kuma power-frequency withstand margin factor da 0.85 suke ci [1], wanda yake jawo reference withstand values a Table 1.

Table 1 Insulation Withstand Levels / Reference Withstand Values for Neutral Points

3. Tasirin da Kalkulashin

Yawan ƙarfin substation ta 110 kV tare da biyu masu transformer (Y/Δ) na yin aiki a matsayin daga biyu ƙungiyoyi na 110 kV da farko da harufa ƙungiyoyi na 35 kV. Diagram mai tsawonta shi ne a cikin Figura 1. Don ya ƙasa tasirin girmamawa da ƙasashen magana, mafi girman lokacin da zai iya ƙara shi ita ce mafi girman masu transformer kawai wanda ya ƙara shi, wasu suna ƙara shi ba. Idan an yi tasiri da ƙaramin rayuwa, za mu iya samun tasirin ƙaramin rayuwa a ƙaramin shi na wanda ba a ƙara shi, wanda ke haɗa da ƙasashen abincin. Fassara da zuwa za su bayyana tasirin aiki da tunani da programmin ATP kan hanyar halayyar yanayi.

Figura 1 Diagram Mai Tsawon Substation Ta 110 kV

3.1 Tasirin Rayuwar Ƙaramin Yadda Ya Tafi Daga Lissafin Kirkiro zuwa Substation

3.1.1 Zabiya da Siffar da Muhimmanci na Tasirin Rayuwar Ƙaramin

Muhimmancin sababban tasirin ƙaramin a cikin substations shine tasirin rayuwar ƙaramin da ke tafi daga lissafin kirkiro. Amfani da shi a kan lissafin ya ba za su iya ƙarin da U50% na ƙasar insulator string na lissafin; amma idan ya ƙarin, za su iya kasance flashover a kan lissafin idan ba ta basu substation. Saboda haka, a cikin birnin 1-2 km na lissafin da aka tabbatar da shi don kaɗaɓa rayuwar ƙaramin, tasirin rayuwar ƙaramin da ke tafi zuwa substation ke faruwa daga rayuwar ƙaramin da ke faruwa a kan wuraren. Don rayuwar ƙaramin da ke faruwa daga birnin, amfani da shi a kan lissafin ≤220 kV ana iya ƙarin da 5 kA, da ƙarin da 10 kA a kan lissafin 330-500 kV, tare da nasarar da ya ƙarin da shi [15,17]. Da wannan alama, an yi modeli da shi da funksi mai tsawon double-exponential:
u(t) = k(e⁻ᵃᵗ - e⁻ᵇᵗ),
inda a da b suna da siffar da si, kuma k, a, b suna da damar tasirin ƙaramin, lokacin da take faru, da kuma lokacin da take ƙarin da shi. An yi amfani da shi da tasirin ƙaramin 5 kA da tsawon exponential standard 20/50 μs a kan hakan.

3.1.2 Settin Masu Aiki Na Substation

Tasirin rayuwar ƙaramin suna da harmonics na ƙarin; saboda haka, masu aiki na lissafin na substation suka yi modeli da shi da parametos na ƙarin. Switches, circuit breakers, current transformers (CTs), da voltage transformers (VTs) a cikin substation suka yi modeli da shi da equivalent shunt capacitances. Equivalent input capacitance na transformer ya kunshi Cₜ = kS⁰·⁵, inda S shine capacity na transformer na uku. Don voltage levels ≤220 kV, n=3, da kuma don transformers na 110 kV, k=540. Busbar surge arrester ya zaba YH1OWx-108/290, da kuma neutral-point surge arrester ya zaba YH1.5W-72/186.

3.1.3 Kalkulashe da Bincike

Tasirin ƙaramin da ya faru a ƙaramin shi ya ƙarin da shi idan ya ƙara shi ko idan ba a ƙara shi. An yi simulations don hanyoyi uku: single-circuit single-phase surge, single-circuit two-phase surge, da double-circuit single-phase surge, da kuma idan ya ƙara shi ko idan ba a ƙara shi. Abubuwan da aka bayyana a cikin Table 2.

Table 2 Peak Overvoltage under Locally Grounded / Ungrounded Neutral Conditions

3.1.4 Tattalin Nau'in Amsa

Daga Tafel 2, a cikin sashe-sashen da ake kare ne mai tatuwar transformer yana ci gaba, surge arrester na busbar yana haɗa da nau'in hawan jiki, saboda haka, tatuwar transformer wanda ba ake kare shi ba bai samu hawan jiki mai yawa, kuma surge arrester na tatuwar ba zai yi aiki a kawo karshe. A cikin sashe-sashen da tatuwar transformer ba ake kare shi, hawan jiki na tatuwa yana zama mafi yawa. Idan ba a kasance surge arrester, wannan yana ba da shakka mai yawa ga izoli (hawan jiki na lightning impulse withstand voltage na transformer 110 kV ta graded insulation, idan a duba margin na inganci, shi ne 195 kV). Amfani da surge arrester na tatuwa yana haɗa da tsakiyar hawan jiki mai yawa. Saboda haka, lightning surges na lines ba zai iya sautin izoli na tatuwar da ake fito da surge arrester.

3.2 Hukumomi Lightning Da Ta Zama Na Substation

Idan substation suna da inganci na hukumomi na lightning, amma hukumomi na lightning da suka zama, idan ba a tabbas ba saboda yadda ya fi kan da abubuwa, ana iya faru [2] kuma zai iya haɗa da lafiya na kayayyakin. Saboda haka, tattalin nau'in hawan jiki na tatuwar da ke faru saboda hukumomi na lightning da tushen ayyuka na hukumomi na da ita yana da kyau.

3.2.1 Zabbar Lightning da Parametomata na Substation

Parametomata na substation suna daidai da ma a bayar. An yi aiki a tuntubi da parametomata na lightning na standard (1.2/50 μs) da amfani da amplitudes na 50, 100, 200, da 250 kA. Impedance na wave na channel na lightning an yi amfani da 400 Ω.

3.2.2 Kalkulushi da Tattalin Nau'i

Nau'ukan hukumomi na lightning na busbar na single-phase (hukumomi na two-phase ba su bi) a cikin sashe-sashen da tatuwar transformer yana ci gaba da tatuwar transformer ba ake kare shi, an nuna a Tafel 3 (I da II sun nufin al'amuran da ba ake fito da surge arrester na tatuwa da al'amuran da ake fito da surge arrester na tatuwa, respectively).

Tafel 3 Tsakiyar Hawan Jiki a Cikin Sashe-Sashen da Tatuwar Transformer Yana Ci Gaba / Tatuwar Transformer Ba Ake Kare Shi (Hukumomi Na)

3.2.3 Tattalin Nau'in Amsa

Kamar yadda aka baka a Zaɓuɓi 3, idan hanyar zuwa ce ta kawo da tsari, mutummai masu aikin da ya faru a matsayinta mai sauye ne kadan da kuma jiragen da suka zama mafi yawa. Kafin an samun sallakar aiki, kuma hanyar kan ya faru. A cikin birane da na aiki na matsayinta ba suka sauye ba, mutummai masu aikin da ya faru a matsayinta mai sauye ne kadan da kuma jiragen da suka zama mafi yawa. Kafin an samun sallakar aiki, kuma mutummai masu aikin ba suka zama mafi yawa. Misali, aikin da ya faru a matsayinta mai sauye ne kadan da ya faru a matsayinta mai sauye ne kadan da kuma jiragen da suka zama mafi yawa. Idan an yi aiki da 250 kA, za a iya samun mutummai masu aikin da ya faru a matsayinta mai sauye ne kadan da 224.1 kV. A wannan lokacin, kafin an samun sallakar aiki, kuma hanyar kan ya faru, kuma hanyar kan ya faru.

3.2.4 Bayanin Hukuntar Addinin Samun Yadda

(1) Samun sallakar aiki a matsayinta hanyar (misali, zama YH10Wx-108/290 don hanyar da ba suka sauye ba) don in hada aiki da ya faru a matsayinta hanyar.
(2) Saka aiki da ya faru wa sallakar aiki na matsayinta mai sauye. An samun sallakar aiki da ya faru da 1.5 kA a matsayinta hanyar da 186 kV. An tattauna in a saka wannan aiki da ya faru zuwa 15 kA.

An yi rubutu aiki har zuwa aikin da ya faru a matsayinta hanyar a cikin birane da na aiki da na matsayinta mai sauye, kuma amsar tattalin aikin da ya faru a Zaɓuɓi 4.

Zaɓuɓi 4 Mutummai Masu Aikin da Ya Faru a Matsayinta Mai Sauye Da Sallakar Aiki (Addinin Samun Yadda)

A cikin tabalolin 3 da 4, yadda ake gina abinci a tsakiyar tarumburta ba tana iya kawo hankali ga kawo yawan rayuwar jirgin sama a matsayin tsakiyar tarumburta. Amma, zama da muhimmanci a yi karfin zama ta abinci ya ba da shawarwari a kawo yawan rayuwar jirgin sama. Saboda haka, an fi sani hakan. An ba da shawarwari a kan masanunan abinci su na bayyana a yi takamawa a fagen dukkan karfin zama.

4. Nau'in

a) Yadda ake gina abinci a cikin jerin mafi girman da kuma a matsayin tsakiyar tarumburta, yana iya kawo hankali ga kawo yawan rayuwar jirgin sama a matsayin tsakiyar tarumburta wanda yake samu daga mafi girman.
b) Idan wurin yana samu rayuwar jirgin sama na gargajiya, yana iya samu yawan rayuwar jirgin sama a matsayin tsakiyar tarumburtar da ba ake gina. Wannan yanayi yana da muhimmanci a cikin tattalin da ba ake gina ko kuma da ake gina da kisan kasa, amma a kan al'adun da aka da su a yanzu, yana iya samu lafiya a matsayin tsakiyar tarumburta.
c) Yadda ake gina abinci a tsakiyar tarumburta ba tana iya kawo hankali ga kawo yawan rayuwar jirgin sama; amma, zama da muhimmanci a yi karfin zama ta abinci a matsayin tsakiyar tarumburta, wanda yana iya kawo hankali ga kawo yawan rayuwar jirgin sama.