Q: Dab tsi yog qhov tsis muaj -load poob, thiab cov txheej txheem xeem zoo li cas?
A: Tsis muaj -load poob (P₀), tseem hu ua hlau poob lossis cov tub ntxhais poob, yog lub zog siv thaum lub tshuab hloov hluav taws xob muaj zog ntawm qhov ntsuas hluav taws xob thiab zaus nrog qhov qhib thib ob -circuited.
Cheebtsam ntawm tsis muaj-load poob:
• Hysteresis poob (~60–70% ntawm P₀) - lub zog rau rov qab sib nqus domains (∝ f × B¹·⁶).
• Eddy tam sim no poob (~25–35% ntawm P₀) - circulating currents in laminations (∝ f² × B² × t²).
• Dielectric poob (~1–5%) + I²R hauv thawj winding (tsis pom zoo).
Cov txheej txheem xeem (IEC 60076-1 / IEEE C57.12.90):
|
Kauj ruam |
Kev ua |
Sau ntawv |
|
1 |
Qhib -circuit thib ob (LV sab) |
Xyuas kom muaj kev nyab xeeb - theem nrab yuav ncav cuag qhov hluav taws xob txaus ntshai |
|
2 |
Thov ntsuas Uₙ ntawm qhov ntsuas f rau thawj (HV sab) |
Waveform THD < 5% |
|
3 |
Ntsuas V, I₀, P₀ |
Siv chav kawm 0.2 lub zog ntsuas ntsuas |
|
4 |
Sau kuv ₀ li % ntawm qhov ntsuas tam sim no |
Feem ntau 0.5-5% |
|
5 |
Kho kom raug rau 20℃siv |
Kev kho yog me me rau P₀ |
Yam P₀ tus nqi:
• Kev faib tawm (100 kVA–2.5 MVA): 0.3–0.8% ntawm Pₙ
• Lub zog nruab nrab (5–50 MVA): 0.15–0.4%
• Lub zog loj (100–500 MVA): 0.08–0.2%
• Amorphous core: ~70% qis dua cov nplej-oriented steel
Siab P₀ qhia tias: kev degradation tseem ceeb, interlaminar luv, pob qij txha tsis zoo, thiab dhau -kev zoo siab.
Kev lees txais: ntsuas P₀ Tsawg dua lossis sib npaug rau lav + 15% (IEC 60076-1).