How do you analyze and prevent harmonic resonance in power systems?

Harmonic resonance occurs when system inductive reactance equals capacitive reactance at a harmonic frequency. Analysis involves: building frequency-dependent impedance model, calculating driving-point impedance vs frequency, identifying resonance peaks near significant harmonic frequencies. Prevention methods include: detuning capacitor banks with series reactors (typically 5-7% reactance), relocating capacitors, using harmonic filters tuned below lowest significant harmonic, or active filters. IEEE 519 limits guide acceptable harmonic levels at PCC.