1. GE Global Research Center, 1 Research Circle, Niskayuna, NY 12309.
2. Galvin Center for Electricity Innovation, Illinois Institute of Technology, 10 W 35th St., STE 16D81, Chicago, IL 60616.
3. Electrical and Computer Engineering Dept., Illinois Institute of Technology, 3301 S. Dearborn St., Chicago, IL 60616.
4. Galvin Center for Electricity Innovation, Illinois Institute of Technology, 10 W 35th St., STE 16D81, Chicago, IL 60616 (corresponding author).