變壓器工作原理
Working principle of transformer
變壓器原理圖單相變壓器有兩個線圈共同繞在一個閉合鐵芯上，如右圖所示，其中與電源相連的線圈稱為原邊線圈，與原邊線圈相關的各量的標示符號均在右下角標注以角碼1，如U1、I1等，與負載項鏈的線圈稱為副邊線圈，相關度額各量的標示符號均在右下角標注角碼2，如U2、I2等。JEM電機引接線JEM電機繞組線JEM
The principle diagram of single-phase transformer transformer has two coil winding together in a closed iron core, as shown on the right, wherein the coil connected to the power source is called the primary coil, the symbol associated with the primary winding are marked in the lower right corner to corner 1, such as U1, I1, and negative coil load Necklace called secondary coil, symbol correlation value by weight are in the lower right corner marked corner 2, such as U2, I2 etc..
此變壓器工作原理為：當變壓器的原繞組施以交變電壓u1時，便在原繞組中產生一個交變電流i1，這個電流在鐵芯中產生交變磁通Φ，因為原、副繞組在同一個鐵芯上，所以當磁通Φ穿過副繞組時，便在變壓器副邊產生感應電動勢e2（即變壓電壓）。變壓器中感應電動勢的大小是和線圈的匝數、磁通的大小及電源的頻率成正比。JEM電機引接線JEM電機繞組線JEM
This transformer working principle is: when the transformer primary winding with alternating voltage U1, will produce a I1 alternating current in primary winding, the current alternating flux in the core, because the primary and secondary windings on the same core, so when the flux through the secondary winding, will produce electromotive the potential E2 in the secondary side of the transformer (i.e. voltage transformer). The size of the induction electromotive force in the transformer is proportional to the number of turns, the size of the magnetic flux and the frequency of the power supply.
原副邊電壓計算
Primary side voltage calculation
變壓器中感應電動勢的計算公式為：
The calculation formula of induction electromotive force in the transformer is as follows:
變壓器電動勢計算
Calculation of transformer EMF
上面的公式中各量分表所指：
In the above formula, each quantity table refers to:
E：表示感應電動勢，單位伏特，簡稱伏（V）；
E: the expression of induction electromotive force, unit volt (V);
f：表示電源頻率，單位赫茲（Hz）；
F: the power frequency, unit Hertz (Hz);
N：表示線圈匝數（匝）；
N: the number of turns (turns);
Φ：表示磁通，單位韋伯（Wb）；
It is a magnetic flux, unit Webb (Wb);
由于磁通Φ穿過原、副邊繞組而閉合，所以原、副邊感應電動勢分別為：
As the magnetic flux is closed through the primary and secondary winding, the primary and secondary induced electromotive force is:
變壓器原邊電動勢計算公式
Calculation formula of primary side electromotive force of transformer
變壓器副邊電動勢計算公式
Calculation formula of the EMF at the side of the transformer
兩個公式相除得變壓器變壓比稱為變壓器的變比。
The two division was called the formula ratio of transformer transformer transformer.
變壓器變壓比
Transformer voltage ratio
在一般的電力變壓器中，繞組電阻壓降很小，可以忽略不計，因此在原邊繞組中可以認為電壓U1=E1。由于副邊繞組開路，電流I2=0，它的端電壓U2與感應電動勢E2相等，即U2=E2。所以由上面的原、副邊感應電動勢公式得：
In the general power transformer, the voltage drop of the winding resistance is very small and can be ignored. Therefore, the voltage U1=E1 can be considered in the original side winding. Due to the open circuit of the secondary winding and the current I2=0, its end voltage U2 is equal to the induction electromotive force E2, that is, U2=E2. So from the above, the primary and secondary induced electromotive force formula:
變壓器變壓比
Transformer voltage ratio
公式中K為原邊電壓U1和副邊電壓U2之比，這個K的數值稱為變壓器的變壓比。
In the formula, the K is the ratio of the original side voltage U1 to the secondary voltage U2, and the value of this K is called the transformer voltage ratio.
由上是表明，變壓器原、副邊繞組的電壓比等于原、副繞組的匝數比，因此如果要原、副邊繞組有不同的電壓，只要改變他們的匝數即可。當N1＞N2時，K＞1，變壓器降壓；當N1＜N2時，K＜1，變壓器升壓。
It is shown that the voltage ratio of the primary and secondary winding of the transformer is equal to the ratio of the turns of the primary and secondary windings. Therefore, if the primary and secondary windings have different voltages, the number of turns must be changed. When N1 > N2, K > 1, transformer depressurization; when N1 < N2, K < 1, transformer booster.
對于已經支撐的變壓器而言，其K為定值，故副邊電壓和原邊電壓成正比，也就是說副邊電壓隨著原邊電壓的升高而升高，降低而降低。但加載原邊繞組兩端的電壓必須為額定值。因為，當外加電壓比額定電壓略有超過時，原邊繞組中通過的電流將大大增加，如果把額定電壓為220V的變壓器錯誤的接到380V的線路上，則原繞組的電流將急劇增大，致使變壓器燒毀。
For a transformer that has been supported, its K is fixed, so the secondary voltage is directly proportional to the primary side voltage, that is to say, the secondary side voltage rises and decreases with the increase of the primary voltage. But the voltage at both ends of the original side winding must be rated. Because when the external voltage is slightly higher than the rated voltage, the current in the primary winding will increase greatly. If the transformer with a rated voltage of 220V is mistaken on the 380V line, the current of the original winding will increase sharply, causing the transformer to burn down.
把變壓器的副邊繞組負載接通后，在副邊電路中有電流I2通過，此時，稱變壓器負載運行。由于副邊繞組中電流I2也將在鐵芯中產生磁通（即自感應現象），這種磁通對于原邊電流所產生的磁通而言，是起去磁作用的，即鐵芯中的磁通應為原邊、副邊繞組中電流產生的磁通的合成。但在外加電壓U1和電源頻率f不變的條件下，由近似公式：
After the load of the auxiliary side winding of the transformer is connected, the current I2 is passed in the secondary circuit. At this time, it is called the transformer load running. Because the current in the secondary winding of I2 will also be in the core of magnetic flux (i.e. self induction), the magnetic flux produced by the primary current, is go to the magnetic field, the magnetic flux in the core that the synthesis flux should be generated for the primary current and secondary winding in the. But under the condition of the constant voltage U1 and the power frequency f, the approximate formula:
原邊電壓
Primary side voltage
上式中可以看出，合成磁通Φ應基本保持不變。因此，隨著I2出現，原邊繞組中通過的電流I1將增加，這樣才能使得原繞組中的磁通以免體校副繞組的磁通，另一面維持鐵芯中的合成磁通保持不變。由此可知，變壓器原邊電流I1的大小是由副邊電流I2的大小來決定的。
As can be seen in the upper formula, the synthetic magnetic flux diameter should be basically kept unchanged. Therefore, with the advent of I2, the current I1 in the primary winding will increase, so that the magnetic flux in the original winding will not be allowed to avoid the flux of secondary windings in the secondary school, and the synthetic flux in the core will remain unchanged on the other side. It can be seen that the size of the original current I1 of the transformer is determined by the size of the secondary current I2.
從能量觀點來看，變壓器原邊線圈從電源吸取的功率P1應等于副邊線圈的輸出功率P2（忽略變壓器的線圈電阻和磁通的傳遞損耗），即：
From the energy point of view, the power P1 of the primary coil of the transformer from the power source should be equal to the output power P2 of the secondary side coil (neglecting the coil resistance and the transmission loss of the magnetic flux).
P1=P2 或 I1U1=I2U2
P1=P2 or I1U1=I2U2
所以變壓比：
So the pressure change ratio:
變壓器變壓比
Transformer voltage ratio
由此可見，變壓器原邊、副邊的電流比與他們的匝數比或電壓比成反比。例如一臺變壓器的匝數N1＜N2，是升壓變壓器，則電流I1＞I2；如果繞組匝數N1＞N2為降壓變壓器，則電流I2＞I1。也就是說，電壓高的一邊電流小，而電壓低的一邊電流大。
It can be seen that the current ratio of the primary and secondary sides of the transformer is inversely proportional to the ratio of their turn to turn or the voltage ratio. For example, the turn number of a transformer is N1 < N2, is a boost transformer, then the current I1 > I2; if the number of winding turns is N1 > N2 as the step-down transformer, then the current I2 > I1. That is to say, the side current of high voltage is small and the side current of low voltage is large.
