IoT-Based Automatic Power Factor Correction for PLN Industrial Customers: A Simulation-Based Design and Evaluation of kVArh Penalty Reduction

Abstract

Industrial loads dominated by induction motors tend to have a low power factor (cos φ), drawing excess reactive power from the PT PLN (Persero) grid. Under Ministerial Regulation ESDM No. 7 of 2024, industrial customers whose monthly average power factor is below 0.85 are charged for excess reactive power usage (kVArh) when the kVArh usage exceeds 62% of the kWh usage. The conventional solution, using fixed capacitors or contactor-based APFC regulators that operate locally, adapts slowly to load fluctuations and provides no data for demand side management (DSM). This research proposes the design of an automatic power factor correction (Automatic Power Factor Correction, APFC) system based on the Internet of Things (IoT) that integrates a three-phase smart meter, an ESP32-based edge controller, a switched capacitor bank (step), as well as middleware and a dashboard through the MQTT protocol. The main contributions are a layered architecture and a hysteresis-based switching capacitor switching algorithm that closes the reactive-power control loop. The evaluation is performed analytically through numerical simulation using real PLN I-3 tariff parameters. The simulation results show the average cos φ rising from 0.795 to 0.947, the excess kVArh eliminated, and an estimated cost saving of about 12.5% of the total bill (≈ IDR 308 million/year in the test scenario). This paper is a design-and-simulation study; hardware verification remains future work.