Automatic power factor controller using microcontroller

This abstract describes the design and development of an APFC panel that employs a microcontroller for continuous monitoring and controlling of the power factor of an electrical system. The system automatically switches banks of capacitors to balance reactive power, thereby optimizing efficiency and energy costs. Power factor is one of the most important aspects of electrical distribution networks because it is the measure of how effectively incoming electric power has been converted to usable output. A low power factor indicates that electrical energy is not being put to good use, which results in higher operational costs and additional burdens on the power infrastructure.The APFC system maintains the power factor close to unity by providing automatic reactive power compensation. The AT89C51 microcontroller is used because of its simplicity, low cost, and ease of programming, which makes this a practical alternative to other control approaches. Power factor correction is necessary for the cancellation of reactive power produced by inductive loads. Systems with fixed loads can be manually corrected using switching of capacitor banks. In systems where the load constantly changes and is distributed, automatic control must be utilized to maintain stability in the power factor. The APFC panel resolves this issue by automatically varying capacitors as the load changes.The rapid growth of electronic devices, power electronic converters, and high-voltage equipment demands greater concerns about power quality in AC systems. In most industrial and commercial establishments, the power loads are usually heavy inductive, which then pulls down the power factor. In applications where poor power factors exist, suppliers normally impose a penalty for this. An APFC panel helps resolve these issues by enhancing the performance of power factors and facilitating efficient use of energy. Keywords Power Factor, Microcontroller, Capacitor Banks, Reactive Power, System Efficiency, Energy Costs, AT89C51, Inductive Loads, Unity Power Factor