Read More
Date: 29-3-2021
1589
Date: 7-4-2021
1968
Date: 4-5-2021
2046
|
Power factor
The ratio of the true power to the VA power, PT/PVA, is called the power factor in an ac circuit. If there is no reactance, the ideal case, then PT = PVA, and the power factor (PF) is equal to 1. If the circuit contains all reactance and no resistance of any significance (that is, zero or infinite resistance), then PT = 0, and PF = 0.
If you try to get a pure reactance to dissipate power, it’s a little like throwing a foam-rubber ball into a gale-force wind. The ball will come right back in your face. A pure reactance cannot, and will not, dissipate power.
When a load, or a circuit in which you want power to be dissipated, contains some resistance and some reactance, then PF will be between 0 and 1. That is, 0 < PF < 1. PF might be expressed as a percentage between 0 and 100, written PF%. Mathematically,
When a load has some resistance and some reactance, a portion (but not all) of the
power is dissipated as true power, and some is “rejected” by the load and sent back to
the source as VA power.
|
|
تفوقت في الاختبار على الجميع.. فاكهة "خارقة" في عالم التغذية
|
|
|
|
|
أمين عام أوبك: النفط الخام والغاز الطبيعي "هبة من الله"
|
|
|
|
|
قسم شؤون المعارف ينظم دورة عن آليات عمل الفهارس الفنية للموسوعات والكتب لملاكاته
|
|
|