Energy Shaping Control of a Back-to-Back Converter for Microgrid Applications

The structure and operation of microgrid systems are susceptible to rapid transients and fluctuations in voltage and electrical power. This presents a need for improved control techniques of microgrid interfaces to provide improved levels of power quality to communication and computer data networks. This research presents an energy shaping control method for increased stability of two level back-to-back voltage source converters when interfaced to distributed energy resources to provide a smooth transition between grid-connected and islanded modes of operation as well as during switching events when reconfiguring power flow between wind and solar resources. The proposed energy shaping control framework is implemented to achieve stability and mitigate system disturbances for two-level back-to-back voltage source converters in a microgrid testbed based on a 13.8kV 4.75MVA industrial testfacility. The system is simulated in Matlab/Simulink (TM) for the reduced-scale 200 VA microgrid system and the results validate the robustness of the proposed controller.