Development of an Automatic Power Factor Control System for a Single-Phase Electrical System Using a Mini PLC

Abstract

This research aims to develop and evaluate an automatic power factor control system for a single-phase electrical system using a mini PLC. The system is designed to automatically adjust the power factor through a mini PLC board serving as the controller. Key components include capacitors for power factor correction and a load simulator consisting of a fluorescent lamp with a magnetic ballast and an induction motor. The controller uses an 8-input, 8-output Mitsubishi Fx3u mini PLC programmed with GX Work 2, and system operation is carried out via a 4.3-inch touchscreen with selectable manual and automatic modes.

Performance testing was conducted on three load conditions: fluorescent lamp, induction motor, and mixed load. For the fluorescent lamp load, the initial power factor was 0.43, and the target power factor was 0.90. After correction, the system achieved a power factor of 0.89, with an error of 0.01. For the induction motor load, the initial power factor was 0.54, with the same target of 0.90; the corrected value was 0.89, also with an error of 0.01. Under mixed load conditions, the initial power factor was 0.48, and the corrected power factor reached 0.89, again with an error of 0.01.

The results demonstrate that the developed automatic control system effectively corrects and improves the power factor across various load conditions in a single-phase electrical system, confirming its capability and practical applicability.