1. A SURVEY OF SYSTEMS TO INTEGRATE DISTRIBUTED ENERGY RESOURCES AND ENERGY STORAGE ON THE UTILITY GRID Joseph A. Carr, Juan Carlos Balda, H. Alan Mantooth National Center for Reliable Electric Power Transmission University of Arkansas

2. Simple Direct Grid Connection

3. PEI For Doubly Fed Induction Generator

4. Voltage Step-Up  Most DER’s Requires boost or step-up transformers  Transformers provide isolation required by the National Electric Code

5. Multiple Connections  DER’s require arrays of individual modules  Array limited to weakest module

6. Separate Grid Connections  Advantages  Optimize each PEI to the DER  Each PEI is simple  Disadvantages  Grid Power Line Use  Increased power electronics

7. Microgrid Connections  Consolidate DERs on single bus  3 types:  Line Frequency  DC Bus  High Frequency AC

8. Line Frequency Microgrid

9. DC Microgrid

10. High Frequency AC Microgrid

11. Multiport Converters  Common Bus like Microgrids  No Direct Local Load Connection  Regulation of Bus not needed  Converters do not have to match bus specifications

12. Standalone Multiport

13. Modular Multiport

14. High Frequency Multiport

15. Modular HF Multiport

16. Summary