An Advanced Real-Time Electro-Magnetic Simulator for power systems with a simultaneous state-space nodal solver

This paper presents a simulation method that combines state-space analysis with a nodal method for the simulation of electrical systems. This paper extends the concept of a discrete companion branch equivalent of the nodal approach to state-space described systems, and enables natural coupling between them. The flexible clustering of state-space described electrical subsystems into a nodal method has the following advantages: first, the nodal admittance matrix can be constrained in size while still permitting the solution of a switched network by nodal admittance matrix on-line triangularisation. Also, each group can have a precalculation of all internal modes (caused by switches, for example) within itself, an important feature for real-time applications. Secondly, the state-space formulation enables the use of higher-level discretization methods with L-stability properties. Finally, the approach enables the coupling of complex nodal-based models like FD-line into a state-space based solver. The method is implemented in a commercial real-time simulation software tool, the Advanced Real-Time Electro-Magnetic Simulator (ARTEMiS).