Design, Construction and Evaluation of a Power Factor Monitoring and Correction System

Abstract

As a measure of how efficiently an electrical power is converted into useful output,
power factor (PF) is a special requirement of every electrical load. A poor power
factor is usually the result of a significant phase difference between the voltage
and current at the load terminals, high harmonic content or a distorted current
waveform. With advancement in research and manufacturing, various techniques
have been adopted in the development of power factor correction equipment and
power optimizers. This work develops a sophisticated system that measures and
corrects the power factor of a given load. The system’s development includes
circuit design algorithm, embedded software programming, embedded web
server/application development, and hardware implementation. A high-end
technology built around a 32-bit ARM Cortex M3 microcontroller is employed to
provide high precision in power factor measurement and supplies the required
reactive power (kVAr) to correct the phase difference between the current and
the voltage of a given electrical load. The corresponding load voltage and current
before and after correction is displayed on an LCD for user interaction. Also, an
on-board web server developed, provides interaction between the system and a
personal computer over a Wi-Fi network. The measured parameters are plotted
on a web browser when connected. The system operates in accordance with the
design specifics, driving the PF of a standing fan from 0.1 to 0.32 values.