Time-domain analysis of reactive power compensation for voltage stability in wind-integrated power networks

This paper presents a time-domain simulation study of dynamic reactive power compensation for voltage stability in a wind-integrated power system.A 50 MW doubly-fed induction generator (DFIG) wind farm is connected at bus 9 of the IEEE 14-bus network, comparing two technologies: a Static Synchronous Compensator (STATCOM) with a PI voltage regulator and anti-windup, and a static VAR compensator (SVC) with a thyristor-controlled reactor and first-order lag dynamics.Bus voltages are computed via a full Newton-Raphson power-flow solver on the complete 14 × 14 admittance matrix.Wind speed is modelled using an AR (1) process calibrated to IEC 61400 Class B conditions.Simulations span seven mean wind speeds (3-18 m/s) at 30% penetration, plus a sensitivity analysis across five penetration levels (10-50%) at rated speed.STATCOM reduces bus-9 voltage deviation from 2.79-2.97% to 0.61-0.80%(73-79% reduction); SVC achieves only 59-65% reduction with larger residual fluctuations.This advantage is confirmed by a Monte Carlo analysis (N = 15 independent AR(1) realisations per operating point), which shows STATCOM outperforming SVC at every tested wind speed with high statistical significance (p < 0.001, Wilcoxon signed-rank test), and reproduces on an independent, larger IEEE 30-bus network.Both compensators slightly increase network-wide reactive losses relative to the uncompensated case on the IEEE 14-bus network (STATCOM: +2.9 to +4.4%; SVC: +2.5 to +3.5%).Within the investigated simulation scenarios, both compensators maintained stable operation across all tested wind penetration levels (10-50%) on both networks.