A Study on Estimation of Static Capacitor Capacity in Distribution Systems Using Equal Power Factor Lines

In recent years, it has been pointed out that the power quality of a distribution system is deteriorating due to the increase of harmonics in power systems. When estimating the harmonic sources in a distribution system, it is important to know the locations and capacities of the static capacitors (SCs) located all over the distribution system, as the SCs absorb the harmonics. Due to the current diversification of loads, it may be difficult to accurately estimate the harmonic sources and locations and capacities of SCs by the method of previous study, which uses the correlation between active power and reactive power. This paper proposes a new method for estimating the capacity of SCs using the intercepts of the equal power factor lines of the net resistance and inductance. In addition, the simulations and experiments are carried out in order to verify the validity of the proposed method. © 2025 The Author(s). IEEJ Transactions on Electrical and Electronic Engineering published by Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.