Power Factor


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Related to Power Factor: reactive power

power factor

[′pau̇·ər ‚fak·tər]
(electricity)
The ratio of the average (or active) power to the apparent power (root-mean-square voltage times rms current) of an alternating-current circuit. Abbreviated pf. Also known as phase factor.

Power Factor

 

(cos ɸ), the ratio of the average power of alternating current to the product of the effective values of voltage and current. The maximum value of the power factor is 1. For a sinusoidal alternating current, the power factor is equal to the angle of the phase shift between the sine curves of voltage and current and is determined by the circuit parameters: cos ɸ = r/Z, where ɸ is the phase shift angle, r is the effective resistance of the circuit, and Z is the total impedance. The power factor may have a value different from 1 even in circuits containing only resistances, if the circuits contain any nonlinear sections. In this case the power factor is decreased because of the distorted shape of voltage and current curves.

power factor

In an alternating current, the ratio of the average power (expressed in watts) to the apparent power (expressed in volt-amperes).
References in periodicals archive ?
The power factor correction equipment should be selected based on the required reactive power, the mode of compensation, type of compensation and the expected working conditions.The location of low-voltage capacitors in an installation constitutes the mode of compensation, which may be central (one location for the entire installation), group (section-by-section), or at load level.
The results show that the AL5822 suppresses over 97% of ripple while still achieving a power factor of greater than 0.9.
The aim of this work is to show that by a proper choice of the conduction voltage of a string, acceptable values of the power factor and efficiency of a lamp with only one or two strings can be achieved.
It is the end result of a lot of experimentation to find a soft-shooting load that makes Power Factor.
"A novel soft-switching bridgeless power factor correction circuit," in Proc.
One characteristic of induction motors is that they have a trailing power factor, which is worse during starting and during part load (low torque) operation.
However, many of the ubiquitous self-ballasted CFL or LED lamps (containing integral electronic ballasts) that can be easily screwed into a standard Edison-based lamp socket typically have a relatively low power factor of between 0.40 and 0.60.
The divider generates the power factor using the active power stored in the register and the output of the multiplier2.
* High Efficiency and Power Factor. High electrical conversion efficiency of 97 percent results from the low switching losses of the main circuit elements and the low input side harmonic currents, which also eliminate the need for harmonic filters or power factor improving capacitors.
This is because they have a poor power factor which is a reflection of their inefficient use of electrical energy.
AC variable-speed vector drives have a high power factor at all speeds, while DC drives have a power factor inversely proportional to the speed (see graph).
The commonly used two-stage high power factor circuit not only possesses enormous device parts and does not meet cost reduction, but also encompasses one stage to correct power factor and another converter stage to perform voltage and current regulation.

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