1. DESIGN AND IMPLEMENTATION OF APFC UNIT FOR REDUCING POWER FACTOR PENALTIES IN INDUSTRIES

The power factor of an alternating current (AC) power system directly affects how well electrical energy is used. limited power factor, which is typically caused by inductive loads like motors, transformers, and lighting ballasts, results in a high demand for current. This leads to high transmission and distribution line losses, voltage dips, limited system capacity, and hig her electricity costs. The current study addresses the design, development, and verification of an automated power factor correction (APFC) system using a stepwise capacitor bank and a microcontroller-based controller unit in order to address these issues. The system uses sensor circuits to identify voltage and current waveforms in real time and determines the phase angle. difference to decide the power factor. According to the measured power factor, the microcontroller dynamically switches on or off capa citors to provide the necessary leading reactive power, thus compensating the lagging component caused by inductive loads. The system is implemented using low-cost, easily available components such as a current transformer (CT), potential transformer (PT), zero-crossing detectors, a relay module, and a bank of shunt capacitors. Simulation and experimental confirmation were carried out under different loading conditions to test system performance. The findings exhibit a notable increase in power factor-from levels as low as 0.72 to as high as 0.97-along with line current reduction and improved power quality. Economic assessment also shows substantial annual savings and a brief payback period on investment. The ease, scalability, and efficiency of the system r ender it appropriate for residential, commercial, and small-scale industrial applications, leading to more sustainable energy consumption habits.