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Majenareta anopindirana ndeimwe yemichina yemagetsi inoshandiswa zvakanyanya mumagetsi emazuva ano, kunyanya mumafekitori makuru emagetsi akadai semafekitori emagetsi anofambiswa nemarasha (PLTU), mafekitori emagetsi anofambiswa nemvura (PLTA), mafekitori emagetsi anofambiswa negasi (PLTG), uye mafekitori emagetsi enyukireya (NPT). Anodaidzwa kuti "synchronous" nekuti kumhanya kwawo kwekutenderera kwerotor kunogara kwakabatana zvakananga (synchronous) nefrequency yemagetsi anogadzirwa. Nemamwe mazwi, majenareta anopindirana anoshandura simba remagetsi kubva ku prime mover (water turbine, steam turbine, gas turbine, kana diesel engine) kuita alternating current (AC) electrical energy pa stable frequency. Kuti tinzwisise mashandiro aanoita, tinofanira kuongorora chimiro chawo, pfungwa yemagineti, electromagnetic induction, speed-frequency relationship, uye excitation and voltage regulation processes.
1. Tsanangudzo uye basa remajenareta anowirirana
Jenareta inochinjana (inowanzonzi alternator) inogadzira voltage yeAC ine zvikamu zvitatu musystem yemagetsi. Muchigadzirwa chemagetsi, jenareta iyi ndiyo "moyo" wesystem, ichishandura torque kubva ku prime mover shaft kuita simba remagetsi, iro rinozowedzerwa ne transformer risati raendeswa kune network yekutumira. Chinhu chikuru chakanakira kugona kwayo kugadzira voltage pafrequency inogara iripo chero bedzi kutenderera kweshaft kuchiramba kuri pahuwandu hwayo hwesynchronous.
Muchokwadi, jenareta inochinja-chinja inoshanda zvichibva pamutemo waFaraday we electromagnetic induction: shanduko mu magnetic flux pamusoro pe electrical conductor inoburitsa electromotive force (EMF) kana induced voltage. Mujenareta, iyi shanduko inoitika nekuti rotating magnetic field (mu rotor) inocheka nepakati pe stator coils.
2. Kuvaka kukuru: stator nerotor
Majenareta anopindirana ane zvikamu zvikuru zviviri:
1. Stator (chikamu chisina kumira)
Stator iyi ine musimboti wesimbi wakagadzirwa nelaminated uye ma coil matatu-phase (anowanzo batanidzwa mukubatana kwenyeredzi newye). Apa ndipo panogadzirwa voltage yeAC induced. Nekuti stator haitendereri, kugoverwa kwesimba kune system kuri nyore uye kwakachengeteka, kunyanya kana paine voltage yakakwira.
2. Rotor (chikamu chinotenderera)
Rotor inotakura simba remagineti. Simba iri rinowanzo gadzirwa nemagetsi akananga (DC) anoyerera nemumarori erotor. Kana rotor ikatenderedzwa nechinhu chinofambisa simba, simba remagineti rerotor rinotenderera uye "rinotsvaira" marori e stator, zvichikonzera voltage ye AC.
Kazhinji kune mhando mbiri dzemarotor ejenareta anowirirana:
– Rotor ine simba: matanda akawanda, akakodzera kumhanya kwakaderera senge mafekitori emagetsi emvura.
– Cylindrical rotor (isina kusimba / turbo rotor): matanda asina kusimba, akakodzera kutenderera zvakanyanya senge PLTU/PLTG.
3. Nheyo dzekutanga dze AC voltage induction
Funga nezve rotor semagineti makuru anotenderera. Sezvo matanda erotor anobva kuchamhembe kuenda kumaodzanyemba achipfuura ne stator coil, flux inopindirana ne coil inochinja nguva nenguva: inenge iri pahuwandu hwayo hwepamusoro apo matanda anenge akatarisana ne coil uye pahuwandu hwayo hwepamusoro kana ari kure. Kuchinja uku kweflux kunogadzira induced emf iyo inochinjawo nguva nenguva—mhedzisiro yacho i alternating voltage.
Mujenareta ine zvikamu zvitatu, ma coil e stator akarongwa madhigirii zana nemakumi maviri emagetsi akaparadzana. Izvi zvinoguma nema voltage matatu e sinusoidal ari madhigirii zana nemakumi maviri kunze kwechikamu. Iyi gadziriro yezvikamu zvitatu yakasarudzwa nekuti inoshanda pakutumira simba, inogadzira torque yakapfava pamota, uye inobvumira simba rakawanda.
4. Hukama huripo pakati pekumhanya kwekubatana, frequency, uye huwandu hwemapango
Chinhu chinonyanya kukosha "chinoenderana" hukama hwemasvomhu pakati pe:
– mafrequency emagetsi (f) muHz,
– nhamba yematanda (P) erotor,
- kumhanya kwekutenderera kwerotor (Ns) mu rpm.
Fomura yacho:
\[
N_s = \frac{120 \, f}{P}
\]
Zvinoreva:
– Kana sisitimu iri 50 Hz uye jenareta ine mapango maviri, saka:
\[
N_s = \frac{120 \kawa 50}{2} = 3000 \text{rpm}
\]
– Kana mapango mana:
\[
N_s = \frac{120 \kawa 50}{4} = 1500 \text{rpm}
\]
Kana matanda akawanda, kumhanya kwe synchronous kunodiwa kunoderedza kuti pave ne frequency yakafanana. Ndokusaka ma hydropower plants (ma turbine anotenderera zvishoma nezvishoma) achiwanzoshandisa ma salient-pole rotors ane matanda akawanda, nepo ma steam/gas plants (ma turbine anokurumidza) achiwanzoshandisa ma turbo rotors ane matanda mashoma.
Mujenareta inochinja-chinja, rotor inotenderera nekumhanya kwakafanana kana yakabatana nesystem yesimba yakagadzikana. Kuchinja kwemutoro kunokanganisa kona yesimba uye simba remagetsi kupfuura frequency, chero bedzi grid yakasimba uye prime mover ichidzorwa zvakanaka.
5. Sisitimu yekukurudzira: rotor magnetic field source
Kuti jenareta ibudise voltage, rotor inofanira kunge iine simba remagineti. Simba iri rinogadzirwa nekuwedzeredza—kushandiswa kwemagetsi eDC kune rotor field coil. Kune nzira dzakasiyana-siyana dzekuwedzeredza:
- Kunakidzwa nemhete dzinotsvedza nemabhurashi
DC current inounzwa kuburikidza ne slip rings kuenda kuma rotor coils. Nzira iyi iri nyore asi inoda kugadziriswa kwebhurashi.
- Kufadza kusina mabhurashi
Uchishandisa chinoshandiswa pakuburitsa magetsi (jenareta diki) uye chinodzokorodza chinogadzirisa magetsi, DC current yerotor inogadzirwa pashaft imwe chete isina mabhurashi. Izvi zvakajairika mumajenareta emazuva ano nekuti akavimbika zvakanyanya.
Hukuru hwe excitation current hunokanganisa hukuru hwemagnetic field, iyo inozopedzisira yakanganisa voltage ye generator terminal uye simba re reactive rinotsinhana ne system.
6. Kugadzira uye kudzorwa kwemagetsi (AVR)
Voltage inokonzerwa mu stator inoenderana nezvinhu zvakawanda, kunyanya:
– simba remuchina wemagineti werotor (rinokonzerwa nekuwedzera simba remagetsi),
- kumhanya kwekutenderera (kwakabatana nefrequency),
- huwandu hwekutenderera uye dhizaini ye stator coil.
Mukuita, voltage yejenareta inofanira kuchengetedzwa mukati memiganhu yakatarwa kunyangwe mutoro uchichinja. Saka, Automatic Voltage Regulator (AVR) inoshandiswa. AVR inoongorora voltage yeterminal uye yobva yawedzera kana kuderedza rotor excitation current kuti irambe yakagadzikana voltage.
Sezvo mutoro uchiwedzera, simba remagetsi rinokwira, zvichikonzera kudzikira kwemagetsi nekuda kweimpedance yemukati mejenareta. AVR "ichatsiva" nekuwedzera kufadza kuti voltage irambe iripo.
7. Kushanda pamwe chete netiweki (kuwiriranisa)
Jenareta yesynchronous isati yabatanidzwa negrid yemagetsi, maitiro ekuenzanisa anofanira kuitwa, kureva equalizing:
1. Voltage (kukosha kweRMS),
2. Kuwanda,
3. Kutevedzana kwechikamu,
4. Kona yechikamu panguva yekuvharwa kwemuchina wekubvisa tambo.
Kana jenareta yakabatana negrid isina kuenderana zvakanaka, inogona kugadzira ma "shock currents" makuru uye torque yemagetsi inogona kukuvadza michina. Kana yabatanidzwa, kumhanya kwerotor "kwakakiyiwa" kune frequency yesystem (inoramba yakabatana), nepo simba rinoita basa richinyanya kutsanangurwa ne prime mover torque.
8. Simba rinoita basa uye simba rinoita basa mumagetsi anoenderana
Muhurongwa hweAC, jenareta inopa:
– Simba rinoshanda (P): rine chekuita nesimba chairo rinoshandiswa nemutoro (kW kana MW).
– Simba rekuita basa (Q): rine chekuita nekuumbwa kwesimba remagineti pamutoro weinductive/capacitive (kVAr kana MVAr).
Kazhinji:
– Simba rinoshanda rinodzorwa nekugadzirisa torque/mechanical input (semuenzaniso kuvhurwa kwevharuvhu yemutsi, kuyerera kwemvura, kana kuwanikwa kwemafuta).
– Simba remagetsi rinoita basa uye voltage yemagetsi inodzorwa nemagetsi ekufambisa simba.
Kana kukwidza kukawedzera (kunyanya kufara), jenareta inowanzopa simba rekuita basa kugrid uye inobatsira kukwidza voltage yesystem. Kana kukwidza kukaderera (kusafara zvakanyanya), jenareta inotora simba rekuita basa uye voltage inowanzo kuderera.
9. Kesimpulan
Nheyo yekushanda kwejenareta inopindirana yakavakirwa pakugadzirwa kwemagetsi: rotor inofambiswa neDC inogadzira simba remagineti rinotenderera, rinocheka ma coil e stator uye rinoita kuti pave ne voltage ye AC ine zvikamu zvitatu. Kusiyana kwejenareta inopindirana ihukama hwakananga pakati pehuwandu hwemagetsi anobuda uye kumhanya kwekutenderera uye huwandu hwemapango, ayo akagadzirwa se \(N_s = 120f/P\). Mukushanda chaiko, kugadzikana kwemagetsi kunochengetwa neAVR kuburikidza nemutemo we excitation, nepo simba rinoshanda richidzorwa ne prime mover. Nekuda kwekushanda kwavo kwakasimba, kushanda zvakanaka, uye kugona kudzora voltage uye simba re reactive, majenareta anopindirana ndiwo musimboti wekugadzira magetsi nemasisitimu pasi rese.
