Accuracy Enhancement of Shifted Frequency-Based Simulation Using Root Matching and Embedded Small-Step

Electromagnetic transients (EMT) simulation is fundamental in power system design and operation. To improve the computational efficiency of EMT simulation, the shifted frequency-based EMT (SFEMT) simulation with large time-steps has been proposed in the literature recently. Nevertheless, the existing SFEMT simulation methods with a large time-step have accuracy issues when there is a sudden change in the power system. In this paper, the causes of the poor accuracy of traditional SFEMT simulation in sudden-change scenarios are first analyzed. Then, it proposes a highly accurate SFEMT simulation algorithm based on the root matching (RM) and embedded small-step (ESS) techniques. Next, the RM-based SFEMT (RM-SFEMT) models of the power system components are derived and the flowchart of RM-SFEMT simulation with ESS is presented. Test results on three power systems of different scales demonstrate the improved accuracy of the proposed SFEMT simulation algorithm.