1. State Key Laboratory for Alternate Electrical Power System with Renewable Energy SourcesNorth China Electric Power UniversityChangping DistrictBeijingPeople's Republic of China
2. School of Electrical, Computer, and Energy EngineeringArizona State UniversityTempeAZUSA
3. Power System DepartmentChina Electric Power Research InstituteHaidian DistrictBeijingPeople's Republic of China