外文翻譯---負(fù)載運(yùn)行的變壓器-其他專業(yè)(存儲版)
【正文】 1011 NININI ?? 。盡管圖中 m? 和 2? 是分開表示的，但它們在鐵芯中是一個(gè)合成量，該合成量在圖示中的瞬時(shí)是向下 的 。互感磁通必須仍隨負(fù)載變化而變化以改變 1E ，從而產(chǎn)生更大的一次側(cè)電流。為了分析 21 NN ? 時(shí)的情況，二次側(cè)的反應(yīng)得從一次側(cè)來看，這種反應(yīng)只有通過由二次側(cè)的磁勢產(chǎn)生磁場力來反應(yīng)。 NININI ?? ，即2122 )/( INNI ? 。 我們可以用一些方法來驗(yàn)證上述折算過程是否正確。折算后的二次側(cè) 2212221222 )/()/(39。 在選擇折算基準(zhǔn)時(shí)，無非是將一次側(cè)與折算后的二次側(cè)匝數(shù)設(shè)為相等，除此之外再沒有什么更要緊的了。2V 折算回 2V而在二次側(cè)兩端引入了一理想的無損耗轉(zhuǎn)換外，其他方面是一樣的。對一個(gè)具體問題可否允許有細(xì)微差別的回答取決于是否允許這種誤差的存在。2V ； （ b） 從二次側(cè)看為一其值為 1V ，且伴有由 1Re 和 1Xe 引起內(nèi)壓降的恒壓源。 ENNE ? which is the same as 1E . For current, since the reaction ampere turns must be unchanged 1222 39。39。2X and 39。2V to 2V .All calculations of internal voltage and power losses are made before this ideal transformation is applied. The behaviour of a transformer as detected at both sets of terminals is the same as the behaviour detected at the corresponding terminals of this circuit when the appropriate parameters are inserted. The slightly different representation showing the coils 1N and 2N side by side with a core in between is only used for convenience. On the transformer itself, the coils are , of course , wound round the same core. Very little error is introduced if the magising branch is transferred to the primary terminals, but a few anomalies will arise. For example ,the current shown flowing through the primary impedance is no longer the whole of the primary current. The error is quite small since 0I is usually such a small fraction of 1I . Slightly different answers may be obtained to a particular problem depending on whether or not allowance is made for this error. With this simplified circuit, the primary and referred secondary impedances can be added to give: 221211 )/(Re NNRR ?? and 221211 )/( NNXXXe ?? It should be pointed out that the equivalent circuit as derived here is only valid for normal operation at power frequencies。2 RR ? and 1239。 IENNINNEIEk V A ???? . The argument is sound, though at first it may have seemed suspect. In fact, if the actual secondary 7 winding was removed physically from the core and replaced by the equivalent winding and load circuit designed to give the parameters 1N , 39。 RNNR ? and 22212 )/(39。 2? , for example, by its demagizing action on m? has caused the changes on the primary side which led to the establishment of primary leakage flux. If a low enough leading power factor is considered, the total secondary flux and the mutual flux are increased causing the secondary terminal voltage to rise with load. p? is unchanged in magnitude from the no load condition since, neglecting resistance, it still has to provide a total back . equal to 1V . It is virtually the same as 11? , though now produced by the bined effect of primary and secondary ampereturns. The mutual flux must still change with load to give a change of 1E and permit more primary cur
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