A portable fast algorithm for solving power electric and electronic networks, and its implementation in the real-time simulator OVNI, are introduced. The implementation of OVNI, object virtual network integrator, on an off-the-shelf hardware platform, a 400 MHz Pentium-II workstation is presented. Simplified fast-models, based on those used by the EMTP, are included for the network elements:​ lumped resistors, capacitors, inductors —both linear and nonlinear— and a constant parameters transmission lines model. Real-time models for HVDC rectifying and inverting bridges, and for the corresponding PIcontrollers, using node hiding, were created specially for OVNI and reported in this thesis. Core saturation and zero sequence flux in three phase core transformers are modelled. Fast non-linear models are included for current and potential transformers. A fast modelling scheme to account for switching operations is presented, and its successful implementation on an industrial product, reported. Multilayer segmentation of the network, topological segmentation followed by MATE segmentation, the node hiding technique, and a history sources limited encapsulation scheme are introduced. Two fast asynchronous commutation modelling techniques —DSDI and BIFE— to eliminate spikes and numerical oscillations are introduced. Industrial real-time test cases are included for power system protective relays, and for high-voltage DC bridges and their corresponding controllers.