Makarantar Polari a Tansufa – Rasa Tsirriyar Da Farkon Aiki

Mafarin Yadda Ake Kula Da Turancin Mafi Tsawo A Turanci Na Zabu Biyu

A turancin mafi tsawo na zabu biyu, daya daga cikin abubuwa na karamin da yake zama mafi tsawo wajen shi ne. Mafarin yadda ake kula da turancin mafi tsawo tana nufin yadda ake kula da ingantaccen voltages bayan mafi tsawon (HV) da mafi kyau (LV). A cikin turancin mafi tsawo na yau da kullum, abubuwan da suka fi sune suna fitar da su waɗanda ake yi nasara da su, kuma mafarin yadda ake kula ta nuna hanyar da ake kula da su da kuma kayayyaki.

Mu'amala ga Mafarin Yadda Ake Kula Da Turancin Mafi Tsawo

Fahimtar mafarin yadda ake kula da turancin mafi tsawo ya shafi wajen gudanar da ayyukan da kuma ayyukan:

• Makamanta Instrument Transformer (CTs da PTs):Mafarin daidai ya ba da muhimmanci don in samun cin kalamomin amfani da voltages a cikin systemen kuliya.

• Koyarar Relay Mai Ingantaccen:Mafarin daidai ya danganta don relays su iya tabbatar da fadada da kuma in yi aiki a cikin hankali.

• Biniyar Turancin Mafi Tsawo na Zabu Uku:Mafarin ya nuna yadda ake kula da karamin da ke dabba saboda mafi tsawon zabu biyu don in bina zabu uku (misalai, delta ko wye).

• Aiki da Turancin Mafi Tsawo a Takaice:Turancin mafi tsawo a takaice ya danganta da mafarin masu damar daidai don in saukar da currents da kuma in bace maganin flux.

Kayayyakin da Mafarin Yadda Ake Kula Da Turancin Mafi Tsawo

Ya fi girma da ake amfani da kayayyakin H1/H2 don primary (HV) windings da X1/X2 don secondary (LV) windings don in nuna mafarin yadda ake kula da turancin mafi tsawo:

• H1 da H2: Alamar da ake amfani da su don kayayyakin da ke dabba saboda mafi tsawon HV, wanda ke nuna maimaita da kima.

• X1 da X2: Alamar da ake amfani da su don kayayyakin da ke dabba saboda mafi tsawon LV (tsohon side).

A lokacin da ake yi mafarin yadda ake kula da turancin mafi tsawo, wasu alamomin ya taimaka wajen:

• Samun ingantaccen voltage relationship bayan mafi tsawon HV da LV (misalai, H1 da X1 ana "in-phase" idan mafarin yake daidai).

• Tabbatar da cewa an yi turancin mafi tsawo a additive (series-aiding) ko subtractive (series-opposing), wanda yake taimaka wajen ake kula da karamin a cikin circuits.

Yadda Ake Bincika

Mafarin da ba daidai ba zai iya haifar da:

• Cin kalamomin da ba daidai ba a instrument transformers.

• Malfunctioning protective relays.

• Excessive circulating currents ko karfi mai zurfi a turancin mafi tsawo na takaice.

Daga ma'anar ake amfani da kayayyakin da su daidai (H1/H2 da X1/X2), engineers da technicians suka iya tabbatar da mafarin yadda ake kula da turancin mafi tsawo, wanda yake taimaka wajen a yi amfani da kuliya a cikin hankali, amincewa da kuma karkashin systemen kuliya.

Mafarin Yadda Ake Kula Da Turancin Mafi Tsawo
Dot convention (ko dot notation) tana da muhimmanci a cikin tarihin ake amfani don in nuna mafarin yadda ake kula da turancin mafi tsawo a cikin transformer.

Mafarin Yadda Ake Kula Da Turancin Mafi Tsawo da Dot Convention

A Figure A, an samun dots a nan darin primary da secondary windings. Wannan tana nuna cewa current da yake kula zuwa dotted terminal of the primary winding yana da hanyar daidai da current da yake kula daga dotted terminal of the secondary winding. Saboda haka, voltages a dotted ends ana in phase—idana voltage a dotted point of the primary yana da tsawo, voltage a dotted point of the secondary zai da tsawo da kuma.

A Figure B, dots suna samun a nan farkon windings, wanda tana nuna cewa windings suna kula a nan farko a nan core. A nan, voltages a dotted points ana out of phase: positive voltage a primary's dotted terminal tana nuna negative voltage a secondary's dotted terminal.

Additive vs. Subtractive Polarity

Mafarin yadda ake kula da turancin mafi tsawo tana da additin ko subtractive. Don in tabbatar da wata, ya kamata a kula terminal daya daga primary winding zuwa terminal daya daga secondary winding kuma a kula voltmeter across the remaining terminals of both windings.

Additive Polarity

• Voltmeter Reading: Ya kasance sum of the primary voltage VA and secondary voltage VB, denoted as VC.

• Formula: VC = VA + VB.

• Winding Configuration: Windings suna kula a nan hanyar da maganin fluxes suna bace wannan idan currents suna kula zuwa dotted terminals.

Circuit diagram of additive polarity is shown in the figure below.

Subtractive Polarity

In subtractive polarity, the voltmeter measures the difference between the primary voltage and the secondary voltage. Denoted as VC, the voltmeter reading is expressed by the equation:

The circuit diagram of subtractive polarity is shown in the figure below.

Circuit Diagram of Polarity Test

The circuit diagram of the polarity test is shown in the figure below.

Polarity Testing of Transformers

The primary winding terminals are denoted as A1, A2, and the secondary winding terminals as a1, a2. As shown in the figure, a voltmeter VA is connected across the primary winding, VB across the secondary winding, and VC between the primary terminal A1 and secondary terminal a1.

An autotransformer is used to provide a variable AC supply to the primary winding. All voltmeter readings are recorded under this configuration:

• If the voltmeter VC reads the sum of VA and VB, the transformer exhibits additive polarity.

• If VC) reads the difference between VA and VB, the transformer exhibits subtractive polarity.

Polarity Test Using a DC Source (Battery)

The AC voltage method described above can be impractical for determining the relative polarity of two-winding transformers. A more convenient approach uses a DC source (battery), a switch, and a DC permanent-magnet voltmeter. The connection diagram for this method—including the correct battery polarity—is shown in the figure below.

A switch is connected in series with the primary winding. When the switch is closed, the battery is connected to the primary winding, allowing current to flow through it. This generates flux linkage in both windings, inducing electromotive force (EMF) in both the primary and secondary windings.

The induced EMF in the primary winding has a positive polarity at the end connected to the battery's positive terminal. To determine the secondary winding's polarity:

• If the DC voltmeter connected across the secondary winding shows a positive reading at the moment the switch is closed, the secondary terminal connected to the voltmeter's positive probe has the same polarity as the primary's positive terminal (i.e., the dotted terminals are correctly identified).

• If the voltmeter deflects to the negative side, the secondary terminal connected to the voltmeter's positive probe has opposite polarity to the primary's positive terminal.