Efficient and accurate representation of asynchronous network structure changing phenomena in digital real time simulators

Due to synchronization requirements related to the interfacing with external systems, digital real time simulators of electromagnetic transients for equipment testing employ a constant integration time step width for solving the network equations. Therefore, the network solution is only calculated at discrete and equidistantly spaced time instants while in reality the time domain is continuous. Changes in network structure that occur between the discrete solution points are generally not simulated exactly. This can lead to switching control mistakes and numerical problems. In this paper the novel clock synchronized structure changing concept, which allows the accurate and efficient simulation of structural changes at arbitrary time instants, is presented.