What is Power Factor Correction?
A. Power factor correction is the term given to a technology that has been used since the turn of the 20th century to restore Power Factor to as close to unity as is economically possible. This is normally achieved by the addition of power factor correction capacitors to the electrical network, which compensate for the Reactive Power demand of the inductive load and thus reduce the burden on the supply. Myron Zucker was the first person to apply Capacitors At the Load (CAL method) to achieve optimal power factor correction.
Poor power factor can be corrected by adding some form of power factor correction to the AC input of the power supply. Power Factor Correction comes in two forms: Active Power Factor Correction, or APFC, and Passive Power Factor Correction. Computer power supplies can create harmonics of the same frequency as the input current, due to the non-linear load caused by the bridge-rectifier doing the AC to DC conversion, and typically have poor power factor (typically 0.55 to 0.65). Passive Power Factor Correction uses a filter that kills any harmonic current and passes current only at line frequency (typically 60Hz in the U.S.) The filters typically come in the form of large, high-value inductors. Active Power Factor Correction is done by using a boost converter in between the bridge-rectifier and main input capacitors. The boost converter attempts to maintain a constant output voltage while drawing a current that is always in phase and at the same frequency as the line voltage. Power facto
Power factor correction is a process that has to do with managing the essential traits of electric loads that are used to create a power factor of less than one. The main purpose of power factor correction is to ensure that the level of power transmission taking place is within safety limits set for the application involved. Power suppliers make use of power factor correction to ensure that home and public building systems are not overloaded, and that manufacturing facilities have an adequate flow of power to operate heavy machinery. There are two basic ways of engaging in power factor correction. One approach relates to the management of power utilized at the end user level. With this application, a homeowner may utilize various devices to minimize or eliminate unnecessary power usage in the home. This may include the installation of such devices as energy saving appliances, or sensors that automatically turn lights off when no one is in the room. A second approach to power factor cor
” An electric utility’s power load on an electrical distribution system fall into one of three categories; resistive, inductive or capacitive. In most industrial facilities, the most common power usages are “inductive.” Examples of inductive loads include transformers, fluorescent lighting and AC induction motors. Most inductive loads use a conductive coil winding to produce an electromagnetic field which permits the motor to function. All inductive loads require two different types of power for the motor to operate: Active power (measured in kW or kilowatts) – this power produces the motive force Reactive power (kvar) – this energizes the magnetic field of the motor. The operating power from the distribution system is composed of both active (working) and reactive (non-working) elements. The active power does useful work in driving the motor whereas the reactive power only provides the magnetic field. Unfortunately, electric utility’s customers are charged for both active and reactive
