Dynamic characterization of power electronic interfaces

Voltage-type sources such as storage battery, ac grid, and constant-output-voltage-regulated converters have dominated as input sources for power electronic interfaces for a long time, leading to the development of different power stages dedicated to voltage-type input sources. Recent penetration of renewable energy sources has initiated the use of current-type sources as well as input voltage regulated converters as input sources for power electronic interfaces. While the power electronic converter topology remains unchanged in both the cases, steady state and dynamic properties of the coupled source-converter system are quite different. Moreover, the voltage/current nature of the load contributes to the complex dynamics as well. This paper investigates the factors determining the dynamic properties of a power electronic converter in a specific arrangement. The findings show that the open-loop converter (without any internal or external feedbacks) automatically adapts its dynamic properties to the properties stipulated by source and load if certain terminal constraints are satisfied. If internal or external feedback is activated, the dynamic properties of the converter may be varied as desired; however, the control design process is substantially different for each source/load arrangement. The findings presented in this paper have not been presented in the literature by far. A buck-power-stage converter is used as an illustrative example. Experimental results are given to validate the analytic investigation outcomes.