Unified averaged switch models for stability analysis of large distributed power systems

Abstract

Unified averaged switch models for PWM converters are presented. The models are applicable for both continuous and discontinuous conduction modes. They have been implemented in SABER and are intended for stability analysis of large distributed power systems. In addition to their simplicity and improved accuracy over existing models, the new models are also capable of providing inductor ripple information. This makes it possible to implement peak current limiting and other protection functions, which is important for large-signal stability analysis of distributed power systems, but has not been possible with existing averaged models. Simulation results from both a DC/DC and a power factor corrected AC/DC converters are presented to validate the accuracy of the models and to demonstrate the robustness of the implementation, especially under abnormal operation conditions.