Abstract: This paper presents the design and implementation of an IoT-based Automatic Power Factor Correction (APFC) system using a Raspberry Pi Pico W microcontroller. In modern electrical networks, inductive loads such as motors and transformers cause a lagging power factor, leading to increased line losses, voltage instability, and penalty charges from utilities. To address these challenges, the proposed system continuously monitors voltage, current, and phase difference using CT, PT, and Zero Crossing Detector circuits. Based on real-time measurements, the controller dynamically switches capacitor banks through relay modules to compensate for reactive power and improve the power factor close to unity.
The system integrates IoT connectivity via the ThingSpeak platform, enabling remote monitoring, data logging, and performance analysis. An LCD display and LED indicators provide local feedback, while cloud-based dashboards enhance transparency and predictive maintenance. Experimental prototype results demonstrate significant improvement in power factor (from 0.70 to 0.97), reduction in energy losses, and enhanced system reliability. The design is compact, cost-effective, and scalable, making it suitable for both industrial and domestic applications.

Keywords: Automatic Power Factor Correction (APFC), IoT, Raspberry Pi Pico W, Current Transformer (CT), Potential Transformer (PT), Zero Crossing Detector, Relay Control, Capacitor Bank, ThingSpeak, Energy Efficiency, Smart Grid.

Downloads: | DOI: 10.17148/IJIREEICE.2026.14513