Resonance-Aware Power Factor Correction in Transmission Networks Using Weighted Indices and Tuned Passive Filters for Harmonic Mitigation

Power factor correction in transmission networks with nonlinear loads cannot be addressed solely from the viewpoint of reactive compensation because harmonic distortion and resonance may compromise the expected technical benefits. In this context, this study proposes a resonance-aware and decision-oriented methodology that integrates nonlinear-load screening, weighted bus prioritization based on power factor degradation and harmonic severity, and tuned passive-filter design validated through impedance-frequency analysis and IEEE 519 compliance criteria. The methodology was implemented in DIgSILENT PowerFactory using the IEEE 14-bus test system, where nonlinear loads were allocated at buses 9 and 14 to emulate converter-dominated operating conditions. Under this scenario, the power factor decreased to 0.78271 and 0.85875, while total harmonic distortion increased to 22.01% and 20.07%, respectively. After the implementation of tuned passive filters, the power factor improved to 0.83023 at bus 9 and 0.90414 at bus 14, whereas total harmonic distortion was reduced to 4.61% and 5.22%, respectively, thus restoring compliance with IEEE 519. In addition, load currents decreased by approximately 16–19%. These results demonstrate that the proposed framework provides a technically consistent procedure for identifying critical buses, mitigating dominant harmonics, improving power factor, and avoiding adverse resonance conditions within a unified compensation workflow.