Transmission line cables: overhead and underground. Stability. Swing equation, power angle equation, equal area criterion, multi-machine system, step-by-step solution of swing equation. Factors affecting voltage and frequency stability. Economic operation within and among plants, transmission-loss equation, dispatch with losses. Flexible AC transmission system (FACTS). Relative power compensation, compensation techniques. High voltage DC transmission system. Power quality – voltage sag and swell, surges, harmonics, flicker, grounding problems; IEEE/IEC standards, mitigation techniques.