Misaloli Armature a Makina na DC?

Mai suna Armature Reaction a Kirki DC?

Takaitaccen armature reaction

Armature reaction a kirki DC yana nuna abin da tattalin armature magnetic flux yake yi a tsari na main magnetic field, wanda yake gina kadan da intenciyonsa.

Cross magnetization

Cross-magnetization saboda current na armature yana taimaka wa tsarin magnetic field ta hanyar har zuwa axis na magnetic neutral, wanda yake gina masu lalace a matsayin efficiencyni.

Brush Shift

Amsa mai zurfi a cikin abin da ya faru shine a rubuta brushes a kan yadda ake gira a generator action da kuma a kan yadda ba ake gira a motor action, wannan zai taimaka a gina kadan air gap flux. Wannan zai gina kadan induced voltage a generator da kuma zai ci gaba a motor. Demagnetizing mmf (magneto motive force) da aka bayar shine:

Idan,

Ia = armature current,

Z = jumla na conductors daban-daban,

P = jumla na poles daban-daban,

β = angular shift of carbon brushes (a electrical Degrees).

Brush shift yana da batutuwar da suka fi shi, saboda haka brushes na iya rubuta a wurin daidai da kasa idan load yana canzawa ko idan yadda ake gira yana canzawa ko idan mode na operation yana canzawa. A nan, brushes suna rubuta a wurin da take daidai da normal load da mode na operation. Saboda batutuwar, hanyar wannan ba ake bukata da ma'ana.

Inter Pole

Batutuwar brush shift ta gina amfani da inter poles a cikin duk medium da large sized DC machines. Inter poles suna da nasara mai girma amma suna da faduwar mai tsirriyar. Suna da polarity na succeeding pole (wanda ke biyo a cikin sequence na rotation) a generator action da proceeding (wanda ya zo a cikin sequence na rotation) pole a motor action. Inter pole an samun da ita don neutralize armature reaction mmf a inter polar axis. Saboda inter poles suna da series with armature, yadda ake gira direction of current in armature yana canza direction of inter pole.

Saboda haka, direction of armature reaction mmf yana cikin inter polar axis. Yana ba commutation voltage don coil da ke undergo commutation hakan da commutation voltage yana neutralize reactance voltage (L × di/dt). Saboda haka, ba za a samu sparking ba.

Inter polar windings suna da series with armature, saboda haka inter polar winding yana da armature current; saboda haka yana yi aiki a tsohon da load, yadda ake gira ko mode na operation. Inter poles suna da faduwar mai tsirriyar don hasashen mafi yawan aikinsu a kan coil da ke undergo commutation da kuma yadda ake gina shi ba tafiyar coils. Base na inter poles suna da faduwar mai girma don kare saturation da kuma bincike response.

Compensating Winding

Abin da kommuta yana da shi a cikin DC machines ba ne. Idan ana iya aiki a cikin heavy loads, cross magnetizing armature reaction zai iya gina very high flux density a trailing pole tip a generator action da leading pole tip a motor action.

Babba, coil da ke cikin wannan tip zai iya gina induced voltage mai yawa da za a iya gina flash over between associated adjacent commutator segments, musamman saboda wannan coil yana da karfin da ya zama close to the commutation zone (at the brushes) inda air temperature zai iya zama mai yawa saboda commutation process.

Compensating windings major drawbacks

• A cikin manyan machines da suka sauka da heavy overloads ko plugging

• A cikin motors mai girma da suka sauka da sudden reversal da high acceleration.