Validation of KESTREL EMT for Industrial Capacitor Switching Transient Studies

Abstract

Electromagnetic transient (EMT) simulation is essential for analyzing sub-cycle switching phenomena in industrial power systems; however, commercial EMT platforms present significant cost barriers for smaller utilities, consultancies, and academic institutions, particularly in developing regions. This paper validates KESTREL EMT, a free and open-source electromagnetic transient solver with Python integration, through three progressive case studies involving industrial capacitor switching transients. This work investigates energization, switching resonance and VFD interactions with capacitor banks. The results demonstrate that KESTREL, when supported by appropriate circuit modeling techniques, produces EMT responses consistent with analytical predictions and established IEEE benchmarks. This work establishes a validated and reproducible methodology for conducting industrial EMT studies using freely available, open-source tools.

Figures (8)

• Figure 1: Industrial facility single-line diagram showing utility source, capacitor bank, Dyn transformer, facility power factor correction, and VFD load.
• Figure 2: Case 1 validation: (a) Full voltage waveform with KESTREL vs. analytical solution over 120 ms. (b) Zoomed view of first 30 ms highlighting 425 Hz oscillation. Dashed lines indicate $\pm$2.0 p.u. theoretical limits.
• Figure 3: FFT spectrum of Case 1 transient voltage showing the 60 Hz fundamental and 420 Hz oscillation.
• Figure 4: Case 2 voltage waveforms: MV bus at utility capacitor bank and LV bus at facility secondary.
• Figure 5: Case 2 per-unit voltage magnification comparison. The Dyn transformer yields a magnification factor of 0.79$\times$.