Explicit formulations for constant-parameter voltage-behind-reactance interfacing of synchronous machine models

Summary form only given. Interfacing of ac electrical machine models in power system transient simulation programs is receiving increasing attention in the literature, wherein models based on the voltage-behind-reactance (VBR) formulation have been recently proposed to achieve a direct interface with external power networks. However, synchronous machine dynamic saliency introduces time-dependent interfacing inductances in traditional VBR models, which increases the computational cost of the overall system solution. This paper presents several new explicit continuous- and discrete-time approximation techniques to eliminate dynamic saliency in VBR models and achieve a simple interfacing circuit with decoupled constant-parameter RL branches. The new models are implemented in MATLAB/Simulink and the PLECS toolbox, and are shown to offer simple and easy-to-use interface, high accuracy, and numerical efficiency as compared to the existing models. The proposed interfacing circuit and approximation techniques can find wide application in common state-variable-based transient simulation programs.