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Power factor is defined only for alternative current. Power factor=1 (largest value) means the alternative voltage and current are in phase with each other. In this case, all the energy coming from the source (generator) is absorbed by the user (load).
A power factor lower than one (in AC) means in a cycle of voltage, in a portion of time the energy is used by the load, but in the rest of the cycle, the energy is going back to the generator.
The main problem with low power factor is LOSS of ENERGY in the wires during the time energy goes back to the generator. During this time the used does not pay for the electricity (and gets negative bill) , however the loss in electric is still there.
Coming back to the main question, equivalent of this situation in DC, happens if the load (user of electricity) becomes generator. An example of this case is an alternators that becomes generator for sometime. Maybe be popularity of wind turbines and reselling back electricity to the grid, the tern "DC power factor" will be defined.
Alain Izad, Ph.D.
What else can I help you with?
Power factor of dc ballast is 0.8. what will be the power factor same ballast in AC?
Power factor is an AC only term, and has no meaning for DC.
What is the power factor of a DC system?
It would be unity, or 1.0. Since the voltage in a DC circuit does not vary with time, there can be no phase displacement of the current waveform, and therefore the current could not lead or lag the voltage waveform.
What does difference between Watt and Volt ampare?
No difference in case of DC. In case of AC Watt refers to Power which includes the factor of power factor. VA does not include power factor.
How you improve power factor in synchronous motor?
Power Factor measures the difference in phase between the current and voltage. When they are in phase the Power Factor is defined as 1. When out of phase the value is less than 1. If they are 180 degrees out of phase the Power Factor will be zero.
Why DC current used largely?
in case of dc losses are very less than in case ac,as power factor is 1
Why dc supply is a unity power factor?
Power factor is a measure of the ratio between the "True Power" and the "Apparent Power" of a system. THe variation from unity arises from the effect of certain components (namely capacitors and inductors) on an AC waveform, causing a phase shift between the current and the voltage. As a DC supply does not suffer from these reactive losses there is no reactive power and the current and voltage are always "in phase". With a phase angle of 0 degrees, the power factor is the cosine of the angle... cos 0 = 1 therefore unity power factor!
Is it possible to measure power factor for dc system?
noAnswer'Power factor' is a quantity associated with alternating-current systems, and does not apply to direct-current systems'.
Why pf maintaining for ac only not in DC?
Power Factor measures the phase shift between current and voltage waveform. Since DC has no frequency there can be no phase shift.
How we calculate load of electrical instrument?
I am not an electrical guy....but since this question was left unanswered....i'll just put in some nonsense!! For AC Load: VxIxPF (V=VoltageRequired, I=Current Required, PF=Power Factor) The Power Factor is normally considered to be 0.8 as a thumb rule. For DC Load: VxI, here the power factor is consisdered to be 1, since it is a DC current !! Byeee!
Why power factor is not present in direct current?
There is no angular gap between voltage & current in Direct Current. So power factor is always cos 0 deg. i.e. 1 for all tha cases of DC.
What is the equation for power in physics?
There are several equations that involve power. The basic definition of power is energy divide by time, so that is one equation. In electricity, if you have a DC current, power = current x voltage. In the case of AC, power = current x voltage x power factor (in many cases, the power factor is close to 1).
How do you charge a supercapacitor?
use a dc power source. preferably an ac/dc power adapter. any dc power source will do.
