Power Factor Correction in Household Appliances

Abstract

The increasing use of inductive loads in domestic and industrial settings leads to reduced power system efficiency. This project implements an automatic power factor correction system using an Arduino microcontroller (ATmega328p) to improve power quality. The system measures power factor from single-phase voltage and current signals, calculates compensation requirements, and switches capacitor banks using a 4-channel relay system. This approach enhances power system stability and efficiency while reducing energy losses, making it suitable for household, domestic, and industrial applications.

Introduction

This project presents an Arduino Uno–based automatic Power Factor Correction (PFC) system designed to improve the efficiency of electrical loads by compensating for reactive power using a shunt capacitor bank. Low power factor, particularly in inductive loads such as motors, increases current, system losses, voltage drops, and electricity costs. The proposed system automatically monitors electrical conditions and switches capacitors according to the required compensation.

System operation

The system consists primarily of:

• Arduino Uno – central controller
• ACS712 current sensor – measures load current
• ZMPT101B voltage sensor – measures load voltage
• Capacitor bank – supplies reactive power
• Relay module – switches the capacitor bank
• LCD display – provides monitoring information

The Arduino measures the RMS voltage and current, determines the power-factor condition, and activates the appropriate capacitor bank when the power factor falls below the desired level. The objective is to maintain the power factor close to unity, with the project targeting greater than 0.95.

Literature survey findings

The literature establishes that power-factor correction provides several benefits:

• Reduced reactive power consumption
• Lower current and I²R losses
• Improved voltage regulation
• Increased system capacity
• Reduced electricity demand charges and penalties
• Lower conductor and cable requirements
• Improved equipment reliability and potentially reduced maintenance
• Better overall energy efficiency

Several PFC strategies are discussed, including individual, group, centralized, fixed, automatic, and mixed compensation. More advanced technologies such as thyristor-controlled series capacitors and synchronous condensers can provide dynamic compensation, although the proposed project focuses on a simpler and lower-cost Arduino-controlled capacitor-bank approach.

Experimental results

The case study at the SPM transformer shed demonstrated a substantial improvement after connecting a 10 kVAR capacitor bank.

The power factor increased from 0.716 to 0.97, demonstrating that the installed 10 kVAR capacitor bank was sufficient to compensate for the inductive reactive power.

The reported reduction in load current after compensation also indicates reduced reactive-current demand. Consequently, the system achieved improved electrical efficiency, reduced losses, and better voltage regulation.

Main conclusion

The study demonstrates that an Arduino-based automatic capacitor-bank controller can provide an effective and economical solution for power-factor correction. By continuously monitoring voltage and current and switching capacitors according to load requirements, the system can maintain a high power factor while reducing reactive power consumption and associated losses.

Recommended improvements

The authors recommend:

1. Regular maintenance and monitoring of capacitor banks.
2. Replacing simple fixed switching with a more sophisticated automatic PFC controller for finer compensation.
3. Assessing other loads to determine whether additional capacitor stages are required.
4. Incorporating multiple capacitor steps rather than a single 10 kVAR stage for better control under varying loads.
5. Adding appropriate protection against overvoltage, overcompensation, and capacitor switching transients.

Conclusion

The analysis of power factor correction (PFC) in household appliances showed significant improvements in electrical efficiency with the addition of appropriately sized capacitors. The power factor improved from 0.60-0.75 to 0.88-0.96, reducing apparent power consumption by 28-32% and current flow in household circuits. Appliances with motors, such as refrigerators and washing machines, showed the most significant improvement, with power factors increasing from 0.62 to 0.94. This led to reduced system losses, minimized voltage drops, and enhanced operational stability. Overall, power factor correction proved to be a practical and effective method for improving household electrical efficiency, making the electrical system safer, more stable, and economical.

References

[1] Power Factor Correction and Energy Monitoring System. [2] https://www.electronicsforu.com/electronics-projects/power-factor- correction. [3] https://www.homemade-circuits.com/power-factor-correction-pfc-circuit/ [4] P. S. R. Murthy et al., \"Energy Efficiency in Household Appliances using Power Factor Correction,\" Journal of Energy Efficiency, vol. 12, no. 3, pp. 1- 10, 2019. [5] R. K. Singh et al., \"Power Factor Improvement of Household Appliances using Power Factor Correction Techniques,\" Journal of Power Electronics, vol. 20, no. 2, pp. 1-8, 2020. [6] J. M. Guerrero et al., \"Passive Power Factor Correction in Household Appliances,\" Journal of Electrical Engineering, vol. 17, no. 1, pp. 1-8, 2017. [7] H. S. Bae et al., \"Active Power Factor Correction using Boost Converter,\" Journal of Power Electronics, vol. 19, no. 1, pp. 1-8, 2019. [8] S. K. Singh et al., \"Reduced Line Losses using Power Factor Correction,\" Journal of Energy Systems, vol. 10, no. 2, pp. 1-10, 2020. [9] R. K. Behera et al., \"Increased System Capacity using Power Factor Correction,\" Journal of Electrical Systems, vol. 15, no. 3, pp. 1-10, 2019. [10] A.K. Gupta et al., \"Cost-Benefit Analysis of Power Factor Correction in Households,\" Journal of Energy Economics, vol. 64, pp. 1-10, 2018.

Copyright

Copyright © 2026 Haritha Poojari, Sharma K V. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.