From Digital Power Electronics and Applications


PFC is the capacity of generating or absorbing the reactive power to a load without the use of the supply. The major industrial loads have an inductive power factor (they absorb reactive power); hence the current tends to go beyond the power is usually used for the power conversion, and an excessive load current represents a loss for the consumer, who not only pays for the over-dimensioning of the cable, but also for the excess power loss in the cables. The electric companies do not want to transport the useless reactive power of the alternators toward the loads; these and the distribution network cannot be used at high efficiency, and the voltage regulation in the various points becomes complicated. The principle used by these electric companies almost always penalizes the low-power factor of the clients; hence the great development of systems for power-factor improvement for industrial processes.

PFC technique has the following methods:

  • Single-phase active power factor correctors

  • Three-phase active power factor correctors

  • Soft-switching active power factor correctors

  • Pulse-width-modulation (PWM) active power factor correctors

  • Passive power factor correctors

  • Single-stage AC/DC converters.

We take a single-stage high-PFC AC/DC converter as an example for digital control application in this section. The system consists of an AC/DC diode rectifier and a double-current synchronous rectifier (DC-SR) Luo-converter as shown in Figure 7.30 [1]. Although SR DC/DC converters are generally used for low-voltage high-current (LVHC) applications, they are available to perform in normal output voltage...

Products & Services
Power Factor Correction (PFC) Products
Power factor correction (PFC) products are used to configure and correct the power factor in power systems.
Power Supplies
Power supplies are electrical devices that deliver electric power to one or several loads. They generate the output power by converting an input signal into an output signal.
AC-DC Converters
AC-DC converters are electrical circuits that transform alternating current (AC) input into direct current (DC) output.
Switching Power Supplies
Switching power supplies are DC sources that use a switching element (normally a power transistor) to generate the desired voltage. Switching power supplies are also called switch-mode products or switching mode power supplies (SMPS).
Power Meters
Power meters are used for high-accuracy measurements of power over a wide-frequency bandwidth, and from both AC and DC circuits.

Topics of Interest

12.4 STATIC COMPENSATION (STATCOM) We investigate the topic of STATCOM, titled Trinary Hybrid Multilevel Inverter Used in STATCOM with Unbalanced Voltages, in this section. A trinary hybrid...

PFC (Power Factor Correction) inductors are used in active boost circuits to correct harmonic current distortion in AC to DC converters. The goal is to achieve a Power Factor (PF) as close to 1.0 are...

AN1106 Power Factor Correction in Power Conversion Applications ® Using the dsPIC DSC The low cost and high performance capabilities of the Author: Vinaya Skanda DSC, combined with a wide variety...

Jos Rodr guez, Ph.D. Pablo Lezana Samir Kouro Alejandro Weinstein, Department of Electronics, Universidad T cnica Federico Santa Mar a, Valpara so, , Chile 11.1 Introduction This chapter is dedicated...

FURTHER READING 1. Luo F. L. and Ye H., Advanced DC/DC Converters, CRC Press LLC, Boca Raton, Florida, USA, 2004. ISBN: 0-8493-1956-0. 2. Wu T. F. and Chen Y. K., A systematic and unified approach...