Riya Bhati
Independent Researcher
India
Abstract
This manuscript presents the design, implementation, and evaluation of an Automatic Power Factor Correction (APFC) unit tailored for industrial loads prevalent up to 2015. The APFC system employs a microcontroller‐based control algorithm to switch capacitor banks in response to real‐time reactive power demand, thereby maintaining the power factor close to unity. Key design considerations include selection of switching devices, sensing circuitry for voltage and current, control logic, and protection features. A prototype was developed using an 8051‐family microcontroller, zero‐cross detectors, and thyristor‐switched capacitor banks. Experimental validation was conducted on representative industrial loads—inductive motors, furnaces, and welding machines—across varying load conditions. Statistical analysis of measured power factor before and after correction demonstrates an average improvement exceeding 25 %. The results confirm the efficacy of the APFC unit in reducing reactive power draw, improving voltage regulation, and lowering utility penalties. Identified research gaps include optimization of control algorithms for harmonic‐rich loads, integration with supervisory systems, and miniaturization for distributed correction. This work provides a foundation for further enhancements in industrial power factor management within the engineering practices of 2015 and earlier.
Keywords
Automatic Power Factor Correction, Capacitor Switching, Microcontroller Control, Industrial Loads, Reactive Power Management
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