This chapter shows how power electronics circuits, electric motors, and drives, can be simulated with modern simulation programs. The main focus will be on PSpice, which is one of the most widely used general-purpose simulation programs and Simplorer, which is more specialized towards the power electronics and motor drives application area. Ali Ricardo Buendia, who obtained his M.S.E.E. degree from Texas Tech University, has created the examples for Simplorer. The PSpice examples have been developed for the free student version of OrCAD Capture 9.1 from Cadence. It is appropriate to reflect upon the value of simulations and its place in the design and analysis process before any in-depth discussion of specific simulation examples. Computer simulations enable engineers to study the behavior of complex and powerful systems without actually building or operating them. The advantage of PSpice that it is based on the almost universal Spice simulation language, which can be seen as the worldwide de facto standard. On the other hand, Simplorer has the advantage of built-in machine models. If both programs are used, comparisons and mutual validations of models can be performed. The reader should always validate any model before it is used for critical engineering decisions. It was pointed out in the introduction, that model validation often means verification that the limitations of the model are not exceeded.