發(fā)電機(jī)的形式很多，但其工作原理都基于電磁感應(yīng)定律和電磁力定律。因此，其構(gòu)造的一般原則是：用適當(dāng)?shù)膶?dǎo)磁和導(dǎo)電材料構(gòu)成互相進(jìn)行電磁感應(yīng)的磁路和電路，以產(chǎn)生電磁功率，達(dá)到能量轉(zhuǎn)換的目的。

發(fā)電機(jī)的分類(lèi)：

直流發(fā)電機(jī)、交流發(fā)電機(jī)、同步發(fā)電機(jī)、異步發(fā)電機(jī)(很少采用)；交流發(fā)電機(jī)還可分為單相發(fā)電機(jī)與三相發(fā)電機(jī)。

  所謂勵(lì)磁即是向同步發(fā)電機(jī)轉(zhuǎn)子提供直流電使其產(chǎn)生直流電磁場(chǎng)的過(guò)程。同步發(fā)電機(jī)轉(zhuǎn)子凹槽內(nèi)的線圈就是由稱(chēng)做勵(lì)磁機(jī)的一個(gè)專(zhuān)門(mén)的設(shè)備為其供以直流電形成直流磁場(chǎng)的。早期的發(fā)電機(jī)是采用單獨(dú)的勵(lì)磁機(jī)給轉(zhuǎn)子線卷提供直流電的系統(tǒng)龐大而復(fù)雜。隨著技術(shù)的進(jìn)步現(xiàn)代同步發(fā)電機(jī)都是將發(fā)電機(jī)與勵(lì)磁機(jī)組裝在一起構(gòu)成一個(gè)完整的發(fā)電機(jī)。

  勵(lì)磁機(jī)其實(shí)就是個(gè)小發(fā)電機(jī)它的工作原理與同步發(fā)電機(jī)一樣。所不同的是它的定子線圈和轉(zhuǎn)子線圈所起的作用與同步發(fā)電機(jī)--主發(fā)電機(jī)正好相反;固定在主發(fā)電機(jī)定子旁的勵(lì)磁機(jī)的定子線圈迫以直流電形成直流磁場(chǎng)，而安裝在主發(fā)電機(jī)轉(zhuǎn)子軸上的勵(lì)磁機(jī)的轉(zhuǎn)子線圈成為輸出電動(dòng)勢(shì)的電樞。勵(lì)磁機(jī)的轉(zhuǎn)子與定子內(nèi)壁之間也是保持著小而均勻的間隙。這也稱(chēng)為旋轉(zhuǎn)電樞式結(jié)構(gòu)的無(wú)刷同步發(fā)電機(jī)。安裝在主發(fā)電機(jī)定子旁的勵(lì)磁機(jī)定子線圈的直流電是由主發(fā)電機(jī)定子線圈即電樞的部分輸出電壓經(jīng)整流后而得到的。與主發(fā)電機(jī)轉(zhuǎn)子同軸安裝的勵(lì)磁機(jī)轉(zhuǎn)子線圈在其定子線圈產(chǎn)生的磁場(chǎng)內(nèi)旋轉(zhuǎn)、切割磁力線所產(chǎn)生的感應(yīng)電動(dòng)勢(shì),經(jīng)同軸安裝在它旁邊的整流器也就是旋轉(zhuǎn)整流器變成直流電流輸?shù)街靼l(fā)電機(jī)的轉(zhuǎn)子線圈使其產(chǎn)生直流轉(zhuǎn)子磁場(chǎng)。從而達(dá)到了對(duì)主發(fā)電機(jī)轉(zhuǎn)子線圈勵(lì)磁的要求。

There are many forms of generators, but their working principles are based on the laws of electromagnetic induction and electromagnetic force. Therefore, the general principle of its construction is to use appropriate magnetic and conductive materials to form magnetic circuits and circuits that induce each other electromagnetically, in order to generate electromagnetic power and achieve energy conversion.

Classification of generators:

DC generator, AC generator, synchronous generator, asynchronous generator (rarely used); AC generators can also be divided into single-phase generators and three-phase generators.

The so-called excitation refers to the process of providing direct current to the rotor of a synchronous generator to generate a direct current electromagnetic field. The coil inside the rotor groove of a synchronous generator is supplied with direct current by a specialized device called an exciter to form a direct current magnetic field. Early generators were large and complex systems that used a separate exciter to provide direct current to the rotor coils. With the advancement of technology, modern synchronous generators assemble the generator and exciter together to form a complete generator.

The exciter is actually a small generator, and its working principle is the same as that of a synchronous generator. The difference is that its stator coils and rotor coils play the opposite role as a synchronous generator - the main generator; The stator coil of the exciter fixed next to the stator of the main generator is forced to form a DC magnetic field with DC electricity, while the rotor coil of the exciter installed on the rotor shaft of the main generator becomes the armature for outputting electromotive force. There is also a small and uniform gap between the rotor and stator inner wall of the exciter. This is also known as a brushless synchronous generator with a rotating armature structure. The direct current of the excitation machine stator coil installed next to the main generator stator is obtained by rectifying the output voltage of the armature of the main generator stator coil. The excitation machine rotor coil installed coaxially with the main generator rotor rotates within the magnetic field generated by its stator coil, and the induced electromotive force generated by cutting magnetic field lines is converted into direct current through the rectifier installed coaxially next to it, that is, the rotating rectifier, and transmitted to the rotor coil of the main generator to generate a direct current rotor magnetic field. Thus achieving the requirement for excitation of the main generator rotor coil.