Reactive Power Compensator Control for Power Factor Improvement Using the Internet of Things
A low power factor caused by inductive loads remains a major issue in electrical distribution systems, leading to an increased reactive power demand and reduced energy efficiency. This study proposes the design and implementation of a three-phase reactive power compensator integrated with Internet of Things (IoT) technology to improve the power factor automatically and in real time. The system employs three PZEM-004T sensors to measure the electrical parameters in each phase, an Arduino Mega 2560 as the main controller, and an ESP32 module for wireless communication with a Firebase real-time database. A mobile monitoring and control interface was developed using the MIT App Inventor, enabling remote access through Android devices. The capacitor bank consists of nine capacitor units arranged as 6.5 µF, 4.0 µF, and 3.5 µF for each phase, which are automatically switched via relays based on the detected power factor and reactive power compensation requirement. Experimental testing under laboratory-scale balanced three-phase fluorescent lamp loads showed that the proposed system improved the power factor from an initial range of 0.43–0.44 to 0.90–0.93 after compensation. The system response time ranged from 2–9 s under static load conditions, 6–12 s during dynamic load changes under compensation, and 1–16 s under over-compensation conditions. The longer response time in the overcompensation test occurred during transitions that required capacitor disconnection and re-selection of the appropriate capacitor combination. The IoT-based monitoring system was evaluated by comparing the PZEM-004T readings with those of a conventional power quality analyzer, Lutron DW-6095. The measurement differences ranged from 0.4–1.1 V for voltage, 0.00–0.03 A for current, and 0.00–0.03 for the power factor. The corresponding percentage errors were 0.17–0.47%, 0.0–9.7 %, and 0.0–5.0% for voltage, current, and power factor, respectively. The results demonstrate that the proposed IoT-based reactive power compensator is effective in improving the power factor and enabling the remote monitoring of electrical parameters in a three-phase low-voltage system.