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2 MATEMATI»KI MODELPRI UKLAPANJUNEOPTEREΔENOGENERGETSKOGTRANSFORMATORAU ovom poglavlju Êe se analizirati matematiËki modelpri uklapanju neoptereÊenog energetskog transformatora,slika 4a i b. Izmeappleu transformatora itoËke prikljuËka na mreæu postoji kapacitet C, kojimse ekvivalentira prilaz kabelskim ili nadzemnimvodom, kapacitet kondenzatorskih baterija i sl.2 MATHEMATICAL MODEL OFTHE ENERGIZATION OF A NO-LOAD POWER TRANSFORMERThis chapter presents an analysis of a mathematicalmodel of the energization of a no-load power transformer,Figures 4a and b. Between the transformerand the connection point to the network, there is acapacity C, which is equivalent to the capacity of acable or overhead approach line, the capacitance ofthe capacitors etc.Slika 4UklapanjeneoptereÊenogenergetskogtransformatoraFigure 4The energizationof a no-load powertransformera) Shema uklapanja transformatora na mreæu / Simplified electrical circuit of transformer energizationb) OdgovarajuÊa zamjenska shema slike a) / Equivalent electrical circuit of Figure a)Parametri mreæe se dobivaju iz podataka o snazitropolnog kratkog spoja u toËki prikljuËka:The network parameters are obtained from data onthe three-phase short-circuit power at the point ofconnection:(1)Pretpostavlja se da je odnos X / R za danu mreæupoznat, na osnovi kojega se odreappleuje otpor R.Na osnovi poznate nazivne snage transformatoraS TR , te napona kratkog spoja moguÊe je odreditirasipni induktivitet tansformatora:It is assumed that the ratio of X / R for the givennetwork is known, on the basis of which we determineresistance R.On the basis of the known transformer rated powerS TR and the short-circuit voltage, it is possible to determinethe leakage inductance of the transformer:(2)Ostali podaci, djelatni otpor primarnog namotatransformatora R 1 , djelatni otpor izazvan gubicimau æeljezu R m , te nelinearni induktivitet æeljezneOther data, the effective resistance of the primarytransformer winding R 1 , the effective resistance dueto iron core losses R m , and the nonlinear inductanceTokiÊ, A., UglešiÊ, I., NumeriËki proraËun niskofrekvencijskih..., Energija, god. 56(2007), br. 5., str. 584-607TokiÊ, A., UglešiÊ, I.,The Numerical Calculation of..., Energija, vol. 56(2007), No. 5, pp. 584-607590