Chitsanzo cha Mafunso Okambirana pa Magalimoto Amagetsi
Mota yamagetsi ndi makina omwe amasintha mphamvu zamagetsi kukhala mphamvu yamakina. Ndi gawo lofunikira kwambiri pa ntchito zosiyanasiyana zamafakitale, zamalonda, komanso zapakhomo. Kumvetsetsa mfundo ndi momwe magalimoto amagetsi amagwirira ntchito ndikofunikira, makamaka kwa ophunzira aukadaulo ndi akatswiri pantchito zamagetsi. M'nkhaniyi, tikambirana zitsanzo zingapo za mavuto ndi zokambirana zokhudzana ndi magalimoto amagetsi kuti tithandizire kumvetsetsa bwino.
Mfundo Zoyambira za Magalimoto Amagetsi
Tisanayankhe mafunsowa, ndikofunikira kuti tikambirane mfundo zoyambira za ma mota amagetsi. Ma mota amagetsi amagwira ntchito motsatira mfundo ya maginito amagetsi, pomwe magetsi odutsa mu coil amapanga mphamvu yamagetsi yomwe imalumikizana ndi mphamvu yamagetsi ya gwero lakunja kuti ipange kuyenda. Kawirikawiri, ma mota amagetsi amagawidwa m'mitundu iwiri ikuluikulu: ma mota amagetsi olunjika (DC) ndi ma mota amagetsi osinthira (AC).
Zigawo Zazikulu za Mota Yamagetsi
1. Stator: Gawo losasuntha la mota lomwe nthawi zambiri limakhala ndi ma waya kapena maginito okhazikika.
2. Rotor: Gawo lozungulira la mota lomwe nthawi zambiri limakhala ndi ma waya kapena maginito.
3. Koyilo: Waya womwe umazungulira rotor kapena stator kuti upange mphamvu ya maginito.
4. Gwero la Mphamvu: Limapereka mphamvu yamagetsi yofunikira kuyendetsa mota.
Mafunso ndi Kukambirana Zitsanzo
Funso 1: Kuwerengera Liwiro la DC Motor
Funso: Mota ya DC yokhala ndi ma turn 500 pa coil iliyonse imagwira ntchito pa 24V ndi 5A. Ngati constant ya mota \( K_m \) ndi 0.02 Nm/A, werengani liwiro lozungulira la rotor ngati torque yomwe yatuluka ndi 1 Nm.
Kukambirana:
Ndizodziwika kuti:
– Chiwerengero cha ma turn (N) = 500
– Voltifomu (V) = 24V
– Mphamvu (I) = 5A
– Chosasintha cha mota \( K_m \) = 0.02 Nm/A
– Mphamvu (T) = 1 Nm
Kuchokera ku equation yoyambira ya mota ya DC, tikudziwa:
\[ T = K_m \cdot I \]
\[ 1 Nm = 0.02 Nm/A \cdot 5 A \]
\[ 1 Nm = 0.1 Nm \]
Izi zikutanthauza kuti mphamvu yokhazikika ya torque yomwe imafunika kuti ipange 1 Nm pa 5 A ndi yolondola.
Kenako, kuti muwerenge liwiro lozungulira (\( \omega \)):
\[ E = K_m \cdot \omega \]
\[ V = E \]
\[ 24V = 0.02 Nm/A \cdot \omega \]
Kuchokera apa, tikhoza kuwerengera liwiro (\( \omega \)):
\[ \omega = \frac{V}{K_m} \]
\[ \omega = \frac{24V}{0.02 Nm/A} \]
\[ \omega = 1200 rad/s \]
Funso 2: Kugwira Ntchito Bwino kwa Mota Yoyambitsa AC
Funso: Mota yolowetsa mphamvu ya magawo atatu ili ndi mphamvu yolowera ya 30 kW ndi mphamvu yotulutsa ya 27 kW. Werengani momwe motayo imagwirira ntchito.
Kukambirana:
Ndizodziwika kuti:
– Mphamvu yolowera (P_in) = 30 kW
– Mphamvu yotulutsa (P_out) = 27 kW
Kugwira ntchito bwino kwa mota (\( \eta \)) kungawerengedwe pogwiritsa ntchito fomula iyi:
\[ \eta = \left( \frac{P_{out}}{P_{in}} \right) \times 100\% \]
\[ \eta = \left( \frac{27 kW}{30 kW} \right) \times 100\% \]
\[ \eta = 0.9 \nthawi 100\% \]
\[ \eta = 90\% \]
Chifukwa chake, mphamvu ya injini yopangira ndi 90%.
Funso 3: Mota Yogwirizana
Funso: Mota yolumikizana ili ndi ma poles anayi ndipo imaperekedwa ndi ma frequency a 60 Hz. Werengani liwiro lolumikizana la mota.
Kukambirana:
Ndizodziwika kuti:
– Chiwerengero cha ndodo (P) = 4
– Mafupipafupi (f) = 60 Hz
Liwiro logwirizana (n_s) la mota yolumikizana likhoza kuwerengedwa pogwiritsa ntchito fomula iyi:
\[ n_s = \frac{120 \cdot f}{P} \]
\[ n_s = \frac{120 \cdot 60}{4} \]
\[ n_s = \frac{7200}{4} \]
\[ n_s = 1800 \, RPM \]
Chifukwa chake, liwiro logwirizana la mota yolumikizana ndi 1800 RPM.
Funso 4: Mzere wa DC Motor Torque
Funso: Mota ya DC series ili ndi coil resistance ya 0.5 ohms ndipo imaperekedwa ndi voltage ya 120V. Ngati mphamvu yamagetsi ndi 10A, werengani torque ngati torque constant ndi 0.1 Nm/A².
Kukambirana:
Ndizodziwika kuti:
– Kukana kwa coil (R) = 0.5 ohm
– Voliyumu yoperekera (V) = 120V
– Mphamvu (I) = 10A
– Mphamvu yosasinthika \( K_t \) = 0.1 Nm/A²
Choyamba, werengerani kutsika kwa magetsi pa coil:
\[ V_R = I \cdot R \]
\[ V_R = 10A \cdot 0.5 \Omega \]
\[ V_R = 5V \]
Mphamvu yamagetsi yogwira ntchito (V_eff) imagwira ntchito pa mota:
\[ V_eff = V – V_R \]
\[ V_eff = 120V – 5V \]
\[ V_eff = 115V \]
Torque (T) ikhoza kuwerengedwa pogwiritsa ntchito fomula iyi:
\[ T = K_t \cdot I^2 \]
\[ T = 0.1 Nm/A² \cdot (10A)^2 \]
\[ T = 0.1 Nm/A² \cdot 100 A² \]
\[T = 10 Nm \]
Chifukwa chake, mphamvu yamagetsi yopangidwa ndi mota ya DC ndi 10 Nm.
Funso 5: Choyambitsa Magalimoto Oyambitsa
Funso: Katswiri wamakina amaika choyambira cha nyenyezi pa mota ya 50 kW. Werengani mphamvu yoyambira yoyamba ngati magetsi ogwirira ntchito ndi 400 V ndipo motayo ili ndi mphamvu ya 92%.
Kukambirana:
Ndizodziwika kuti:
– Mphamvu ya injini (P) = 50 kW
– Voltifomu (V) = 400V
– Kuchita bwino (\( \eta \)) = 92%
Choyamba, timawerengera mphamvu yolowera (P_in):
\[ P_{in} = \frac{P}{\eta} \]
\[ P_{in} = \frac{50 kW}{0.92} \]
\[ P_{in} = 54.35 kW \]
Popeza mota imagwiritsa ntchito njira ya nyenyezi-delta, mphamvu yoyambira mu nyenyezi idzakhala yotsika kuposa mphamvu panthawi yogwira ntchito ya delta. Komabe, kuti tiwerenge mphamvu ya nominal, tingagwiritse ntchito P_in ndi V:
\[ I_{nom} = \frac{P_{in}}{\sqrt{3} \cdot V} \]
\[ I_{nom} = \frac{54.35 kW}{\sqrt{3} \cdot 400V} \]
\[ Ine_{nom} = \frac{54350}{692.82} \]
\[ I_{nom} \pafupifupi 78.44 A \]
Poyambira magetsi pogwiritsa ntchito njira yoyendera nyenyezi:
\[ I_{start\_star} = \frac{I_{nom}}{\sqrt{3}} \]
\[ I_{start\_star} \pafupifupi \frac{78.44A}{\sqrt{3}} \]
\[ I_{start\_star} \pafupifupi 45.28 A \]
Kotero, mphamvu yoyambira yoyamba mu star circuit ndi pafupifupi 45.28 A.
Mapeto
Kumvetsetsa mawerengedwe oyambira a mitundu yosiyanasiyana ya ma mota amagetsi ndikofunikira kwa iwo omwe amagwira ntchito zamagetsi ndi zamakina. Kuchokera ku zitsanzo zamavuto omwe ali pamwambapa, titha kuwona momwe magawo osiyanasiyana monga magetsi, mphamvu, mphamvu, ndi magwiridwe antchito amathandizira pakuzindikira magwiridwe antchito a mota yamagetsi. Ndi machitidwe okhazikika, kuthekera kothetsa mavuto ngati awa kudzakhala kofunikira kwambiri pakugwiritsa ntchito moyenera komanso pantchito.
