1. Intelligent Micro-Grid Demonstrator R. E. Hebner, J. D. Herbst, A. L. Gattozzi Center for Electromechanics University of Texas, Austin May 19, 2010

2. Electric ship Micro-grid Close similarity but with unique features Special characteristics of ship’s power system: Wide variety of loads, from continuous duty to pulsed loads Minimal available margin of generated power over total required Greater reliance on energy storage to supply intermittent loads Many aspects are very similar

3. Micro-grid Technical Challenges Increasing incidence of power electronics Co-existence of ac and dc sections Presence of non-traditional energy resources More decentralized control system Lack of experimental data especially at MW power levels CEM-UT micro-grid demonstrator attempts to bridge this gap

4. CEM-UT Micro-Grid Demonstrator

5. DC Bus: 2 parallel AWG535 DLO cable 2 kV, 1.6 kA, 31 m long

8. Preliminary Investigations Many components developed over time and tested individually Computer models of components Models of various topologies Comprehensive model of micro-grid being developed Preliminary tests on sub-assemblies System stability issues

9. Stability of Common DC Bus Topology

12. Constant Power Load Instability Constant power load fed by dc source:

15. (16) (21)

17. Experimental Test

18. 15 kW 21.5 kW