外文翻譯---負(fù)載運(yùn)行的變壓器-其他專業(yè)-在線瀏覽
2025-03-24 09:45本頁(yè)面
【正文】 VA, 22IE . The physical current has increased, and with in the primary leakage flux to which it is proportional. The total flux linking the primary , 111 ??????? mp , is shown unchanged because the total back .,（ dtdNE /111 ?? ） is still equal and opposite to 1V . However, there has been a redistribution of flux and the mutual ponent has fallen due to the increase of 1? with 1I . Although the change is small, the secondary demand could not be met without a mutual flux and . alteration to permit primary current to change. The flux s? linking the secondary winding has been further reduced by the establishment of secondary leakage flux due to 2I , and this opposes m? . Although m? and 2? are 5 indicated separately , they bine to one resultant in the core which will be downwards at the instant shown. Thus the secondary terminal voltage is reduced to dtdNV S /22 ??? which can be considered in two ponents, . dtdNdtdNV m // 2222 ????? or vectorially 2222 IjXEV ?? . As for the primary, 2? is responsible for a substantially constant secondary leakage inductance 222222 / ??? NiN . It will be noticed that the primary leakage flux is responsible for part of the change in the secondary terminal voltage due to its effects on the mutual flux. The two leakage fluxes are closely related。21 EE ? . Secondly, the physical picture is drawn for a different instant of time from the vector diagrams which show 0??m , if the horizontal axis is taken as usual, to be the zero time reference. There are instants in the cycle when primary leakage flux is zero, when the secondary leakage flux is zero, and when primary and secondary leakage flux is zero, and when primary and secondary leakage fluxes are in the same sense. The equivalent circuit already derived for the transformer with the secondary terminals open, can easily be extended to cover the loaded secondary by the addition of the secondary resistance and leakage reactance. 6 Practically all transformers have a turns ratio different from unity although such an arrangement is sometimes employed for the purposes of electrically isolating one circuit from another operating at the same voltage. To explain the case where 21 NN ? the reaction of the secondary will be viewed from the primary winding. The reaction is experienced only in terms of the magizing force due to the secondary ampereturns. There is no way of detecting from the primary side whether 2I is large and 2N small or vice versa, it is the product of current and turns which causes the reaction. Consequently, a secondary winding can be replaced by any number of different equivalent windings and load circuits which will give rise to an identical reaction on the primary .It is clearly convenient to change the secondary winding to an
環(huán)評(píng)公示相關(guān)推薦
鄂ICP備17016276號(hào)-1