Power system modelling and scripting isa quite general andambitious title. Ofcourse, to embrace all existing aspects ofpower systemmodelling would lead to an encyclopedia.Thus, the bookfocuses on asubset ofpower system models based on the following assumptions:(i) devices are modelled as a set of nonlinear di?erential algebraic equations, (ii) all alternate-current devices are operating in three-phase balanced fundamental frequency, and (iii) the time frame ofthedynamics of interest ranges from tenths to tens ofseconds.These assumptions basically restrict the analysisto transientstability phenomena and generatorcontrols.