Accuracy Quantification of Multi-Rate Electromagnetic Transients Simulation

This article proposes a frequency domain technique to quantify the accuracy of multi-rate electro-magnetic transient simulation. Frequency domain transfer relationships are introduced to mathematically represent the up- and down-sampling processes required for interfacing the large and small time-step subnetworks. These are then used to derive the frequency domain equations for the boundary node voltages. By comparing these with the theoretical ones for the original real-world network, a "simulation accuracy spectrum" is developed to quantify the accuracy of multi-rate simulation. The procedure is demonstrated with the example of multi-rate simulation of the IEEE 39-BUS system connected with a VSC-HVdc converter.