When simulating complex power electronic systems, however, the processes during switching are of little interest. In these situations it is more appropriate to use ideal switches that toggle instantaneously between a closed and an open circuit. This approach, which is implemented in PLECS, has two major advantages: Firstly, it yields systems that are piecewise-linear across switching instants, thus resolving the otherwise difficult problem of simulating the non-linear discontinuity that occurs in the equivalent-circuit at the switching instant. Secondly, to handle discontinuities at the switching instants, only two integration steps are required (one for before the instant, and one after). Both of these advantages speed up the simulation considerably, without sacrificing accuracy. Thus the software is ideally suited for modelling and simulation of complex drive systems and modular multilevel converters, for example.