Dynamical properties of electric machines, networks, loads and integrated systems. Models of power plants, turbines, turbine control, load-frequency control, tie-line control. Models of synchronous machines. Equal area criterion. Small signal stability. Voltage control and static stability. Properties of protection systems: dependability, reliability, selectivity, back-up functions, economy. Line protections: Influence of fault impedance, grounding, time setting. Differential protections. Digital protections. Intelligent protections.