【正文】 ： The transformer is the transformer substation major installation, the function realizes the work voltage rank transformation, the key job principle is the electromagic the substation is realizes the voltage class transformation and the electrical energy assignment place. Carries on the voltage class transformation to the electric power supply, deals with the place which the electrical energy carries on redistributes to be called the transformer substation. Constructs the transformer substation is for electrical power distribution system39。一次側漏磁也一樣。故一次側電流 Ip 是電流 Ip’與 I0’的和。因此當二次側連接著一個負載時，在 瞬間就有一個負荷電流沿著這個方向產生。在第四部分我們會了解到當變壓器帶負荷運行時一次側繞組電流是如何隨著二次側負荷電流變化而變化的。 實際 上 , 變比 從 標識牌數(shù)據(jù) 獲得 , 列出在 滿載 情況下 原邊 和 副邊 電壓。一次側和二次側電壓增長的比率稱做變比。因為沒有電流流過二次側繞組， Es=Vs。兩個相量的分量和代表空載電流，即 I0 = Im+ Ie 應注意的是空載電流是畸變和非正弦形的。這個空載電流有兩項功能：（ 1）在鐵芯中產生電磁通，該磁通在零和 ? φm 之間做正弦變化， φm 是鐵芯磁通的最大值；（ 2）它的一個分量說明了鐵芯中的渦流和磁滯損耗。 從交流電源流入電流的一側被稱為變壓器的一次側繞組或者是原邊。因為最終的負荷，在一些點高電壓必須降低。對供電電源進行電壓等級變換，應對電能進行重新分配的場所稱為變電所。 在電力應用中，使用層式鐵芯變壓器 (本文中提到的 )。這就是變壓器的作用。就是這個分量在鐵芯中建立了磁通；因此磁通 φ 與 Im 同相。正如前文中討論到的，所產生的電壓必定滯后于磁通90186。它遵循 Eavg = N 21/(2 )mf? = 4fNφm 其中 N 是指線圈的匝數(shù)。匝數(shù)比可以衡量二次側電壓相對于一次惻電壓是升高或者是降低。這是一種特殊類型的變壓器，可被應用于當一次側和二次側需要相互絕緣以維持相同的電壓等級的狀況下。這個公式應用于變壓器的阻抗匹配。 在一次側，電流 Ip’在一次側流過以平衡 Is 產生的影響。因為這個磁通不流過一次側繞組，所以它不是一個公共磁通。這就符我們前面計算中可以忽略空載電流的假設。 in phase behind the primary voltage VP. It is this ponent that sets up the flux in the core。 the marked terminals have the same polarity. Thus when a load is connected to the secondary, the instantaneous load current is in the direction shown. In other words, the polarity markings signify that when positive current enters both windings at the marked terminals, the MMFs of the two windings add. In general, it will be found that the transformer reacts almost instantaneously to keep the resultant core flux essentially constant. Moreover, the core flux φ0 drops very slightly between n o load and full load (about 1 to 3%), a necessary condition if Ep is to fall sufficiently to allow an increase in Ip. On the primary side, Ip’ is the current that flows in the primary to balance the demagizing effect of Is. Its MMF NpIp’ sets up a flux linking the primary only. Since the core flux φ0 remains constant. I0 must be the same current that energizes the transformer at no load. The primary current Ip is therefore the sum of the current Ip’ and I0. Because the noload current is relatively small, it is correct to assume that the primary ampereturns equal the secondary ampereturns, since it is under this condition that the core flux is essentially constant. Thus we will assume that I0 is negligible, as it is only a small ponent of the fullload current. When a current flows in the secondary winding, the resulting MMF (NsIs) creates a separate flux, apart from the flux φ0 produced by I0, which links the secondary winding only. This flux does no link with the primary winding and is therefore not a mutual flux. In addition, the load current that flows through the primary windin