Faduwar Zafi na Tansufa

Fadada a Turbin

Saboda turbin ya shirya wani babban gurbin, ba a tafi fadada kisan aikin da yake a turbin. Ana nemi ne mafi yawan fadada aikin a turbin.

Fadan a cikin wani makaranta na iya bayyana a matsayin farko daga kayan abokin gwamnati da kayan aiki. Idan kayan abokin gwamnati ta sa a tsakiyar turbin, baka daya daga cewa kayan abokin gwamnati ana amfani don in yi fadada mai girma a tsakiyar turbin ya'ni fadada hysteresis a turbin da fadada eddy current a tsakiyar turbin da baka daya daga cewa kayan abokin gwamnati ana zama fadada I2R da ke fitowa a tsakiyar da takardunsa.

Baka daya ana kiransa fadada tsakiya ko fadada ferro a turbin da ala kan fadada ohmic ko fadada copper a turbin. Fadada na biyu na faruwa a turbin, an kiransa fadada Stray, saboda fluxes na Stray take haɗa da karkashin aiki da kwayoyi na karkashin aiki.

Fadada Copper a Turbin

Fadada copper shine fadada I²I2R, tare da I12R1 a tsakiyar da I22R2 a takarda. Haka, I1 da I2 suna da kayan abokin gwamnati a tsakiyar da takarda, R1 da R2 su ne resistance daga kwayoyi. Saboda wannan kayan abokin gwamnati ta yi amfani don load, fadada copper a turbin yana canza saboda load.

Fadada Tsakiya a Turbin

Fadada hysteresis da fadada eddy current, duka suna da amfani don kayan aiki da wuraren da ake amfani don in yi tsakiyar turbin da kuma tushen. Saboda haka wannan fadada a turbin su ne fix da ba su canza saboda kayan abokin gwamnati. Saboda haka fadada tsakiya a turbin, wanda ake kiran sake fadada ferro a turbin, za a iya duba cewa sama da duk fadada load.

Fadada hysteresis a turbin an kiransa,

Fadada eddy current a turbin an kiransa,

Kh = Mafarin hysteresis.

Ke = Mafarin eddy current.

Kf = Mafarin form.

Fadada copper za a iya kiransa,

IL2R2′ + Fadada Stray

Idan, IL = I2 = load a turbin, da R2′ shine resistance a turbin da aka taka don takarda.

Daga baya za a tattauna fadada hysteresis da fadada eddy current a fili masu ma'ana don inganta fahimtar fadada a turbin.

Fadada Hysteresis a Turbin

Fadada hysteresis a turbin za a iya tabbatar da biyu: cikakken jami'a da kuma cikakken lissafi.

Cikakken Jami'a ta Fadada Hysteresis

Tsakiyar turbin an yi daga 'Cold Rolled Grain Oriented Silicon Steel'. Steel shine wani babban material na ferromagnetic. Wannan kalloren material suka fi shahara da shirya magita. Yana nufin, idan flux magnetic ya shiga, za a yi shi da magita. Material na ferromagnetic suka da domains a cikinsu.

Domains shine regions na musamman a cikin wuraren material, inda dipoles duka su da kalmomi a hanyar yadda. A bangaren kalloren, domains su ne kamar magnets na daidai da suka yan shiga a cikin wuraren material.

Wannan domains suka haɗa a cikin material a matsayin hanyar da net resultant magnetic field na material shine zero. Idan field magnetic (mmf) na gargajiya an yi, domains da suke haɗa a matsayin random suka haɗa parallel to the field.

Ba field ya rage, domains duka suka rage wa matsayin random, amma some remain aligned. Saboda domains da ba su rage, material an samu magita daidai. Wannan magita an kiransa "Spontaneous Magnetism".

Don in kula wannan magita, an bukata mmf na gargajiya. Magnetomotive force ko mmf an yi a tsakiyar turbin shine alternating. Don kuli cycle da domain reversal, za a yi extra work done. Saboda haka, za a yi consumption of electrical energy wanda ake kiransa fadada hysteresis a turbin.

Cikakken Lissafi ta Fadada Hysteresis a Turbin

Determination of Hysteresis Loss

Za a duba ring daga sample na ferromagnetic da circumference L meter, cross-sectional area a m2 and N turns of insulated wire kamar yadda aka nufin a sune,

Idan an nufin, current an yi a coil shine I amp,

Magnetizing force,

Idan, flux density a wannan lokaci shine B,

Therefore, total flux through the ring, Φ = BXa Wb

Saboda current an yi a solenoid shine alternating, flux produced in the iron ring shine alternating in nature, so the emf (e′) induced will be expressed as,

According to Lenz,s law this induced emf will oppose the flow of current, therefore, in order to maintain the current I in the coil, the source must supply an equal and opposite emf. Hence applied emf,

Energy consumed in short time dt, during which the flux density has changed,

Thus, total work done or energy consumed during one complete cycle of magnetism is,

Now aL is the volume of the ring and H.dB is the area of the elementary strip of B – H curve shown in the figure above,

Therefore, Energy consumed per cycle = volume of the ring × area of hysteresis loop.In the case of transformer, this ring can be considered as magnetic core of transformer. Hence, the work done is nothing but the electrical energy loss in transformer core and this is known as hysteresis loss in transformer.

Me Da Fadada Eddy Current?

A turbin, ana nemi alternating current a tsakiyar, wannan alternating current an yi alternating magnetizing flux a tsakiyar da kuma a lokacin da flux shine haɗa da winding na takarda, za a yi voltage na takarda, result in current to flow through the load connected with it.

Babu alternating fluxes a turbin; may also link with other conducting parts like steel core or iron body of transformer etc. As alternating flux links with these parts of transformer, there would be a locally induced emf.

Due to these emfs, there would be currents which will circulate locally at that parts of the transformer. These circulating current will not contribute in output of the transformer and dissipated as heat. This type of energy loss is called eddy current loss of transformer.

This was a broad and simple explanation of eddy current loss. The detail explanation of this loss is not in the scope of discussion in that chapter.