Saboda haka, masu ma'adani da suka sanin shi suna neman cewa voltage transformer (VT) ba za a yi aiki da shi a matsayin short-circuited, kuma current transformer (CT) ba za a yi aiki da shi a matsayin open-circuited. Idan a yi short-circuit VT ko a yi open-circuit CT, zai kashe shi ko kuma zai taimakawa wani abu mai yawa.
Daga fahimtari, VT da CT ne su transformers, amma farkon da ke tsakanin su ita ce abubuwa da suke gina. Saboda haka, idan suke fiye na abin da suke gina, mace mutanen da suke neman cewa aikinsu ya bambanta?
A cikin aikin daidai, secondary winding na VT ta yi aiki a matsayin near-open-circuit condition tare da ZL mai yawa. Idan aikin da na shi ya yi short, ZL yake rage zuwa zero, wanda yake taimaka waɗanda aiki mai yawa a yi aiki. Wannan zai iya kashe shi ko kuma taimakawa wani abu mai yawa. Don in inganta haka, ana iya saukar fuses a karshe na secondary side don in inganta hankali. A lokacin da mumkinta, fuses na da kyau a sauka a primary side don in inganta high-voltage system daga faults na VT’s high-voltage winding ko connections.
Amma, a cikin aikin daidai, CT ta yi aiki a matsayin low-impedance (ZL) a karshe, wanda yana cikin short-circuit state. Magnetic flux na secondary current ta iya kanja da magnetic flux na primary current, wanda yake taimaka waɗanda net excitation current da minimal core flux. Saboda haka, induced electromotive force (EMF) na secondary winding ta fi shi domin a few dozen volts.
Amma, idan aikin da na shi ya yi open, secondary current yake rage zuwa zero, wanda yake kawo off demagnetizing effect. Primary current, wanda bai rage bayan ε1 bai ci gaba, yake ci gaba a yi aiki a matsayin excitation current, wanda yake taimaka waɗanda increase dramatic core flux Φ. Core ta rage zuwa saturation. Daga cewa secondary winding ta fi shi many turns, wannan ta taimaka waɗanda high voltage (da zai iya rage zuwa several thousand volts) a matsayin open secondary terminals. Wannan zai iya kashe insulation ko kuma taimakawa wani abu mai yawa. Saboda haka, open secondary circuit na CT ba za a yi aiki.
VT da CT ne su transformers a cikin principle—VT ta gina voltage, kuma CT ta gina current. Saboda haka, mace mutanen da suke neman cewa CT ba za a yi open-circuited, kuma VT ba za a yi short-circuited?
A cikin aikin daidai, induced EMFs ε1 da ε2 suna ci gaba constant. VT ta yi aiki a matsayin parallel connection, a matsayin high voltage da very low current. Secondary current ta fi shi extremely small, nearly zero, wanda yake cika balanced condition tare da infinite impedance of an open circuit. Idan aikin da na shi ya yi short, ε2 ta ci gaba constant, wanda yake taimaka waɗanda secondary current ta rage, wanda zai iya kashe secondary winding.
Kamar haka, CT ta yi aiki a matsayin series connection, a matsayin high current da very low voltage. Secondary voltage ta fi shi nearly zero a cikin aikin daidai, wanda yake cika balanced state tare da near-zero impedance (short-circuit). Idan aikin da na shi ya yi open, secondary current ta rage zuwa zero, kuma primary current ta ci gaba a yi aiki a matsayin excitation current. Wannan zai taimaka waɗanda surge dramatic magnetic flux, wanda yake taimaka waɗanda core ta rage zuwa deep saturation, kuma zai iya kashe transformer.
Saboda haka, musamman haka su transformers, amma applications da suke gina sun taimaka waɗanda operational constraints da suke bambanta.
