An Efficient Voltage-Behind-Reactance Synchronous Machine Model for Multi-Scale Transients Using Shifted-Frequency Analysis

In this paper, an efficient voltage-behind-reactance synchronous machine model using shifted frequency analysis for dynamic phasor based electromagnetic transients-type solution is presented by extending the earlier works. The proposed machine model has a constant equivalent admittance matrix for direct machine-network interface, thereby eliminating the expensive re-factorization of the network admittance matrix at every integration time step. This feature is realized by the use of numerical approximation of machine dynamic saliency and a linear predictor. Moreover, to achieve a higher degree of accuracy, an iterative procedure is included. The model is based on shifted-frequency analysis, which allows for precise and efficient simulation of multi-scale power system transients with a large integration time step. A number of case studies were conducted and the results demonstrated the superiority of the proposed model over traditional time domain models. The machine model is better suited to study power system operational dynamics, including fast network transients.