1. School of Electrical EngineeringWuhan UniversityWuhan430072Hubei ProvincePeople's Republic of China
2. CSG Electric Power Research InstituteGuangzhou510080Guangdong ProvincePeople's Republic of China
3. Jangsu Electric Power Company Economic Research InstituteNanjing210008Jangsu ProvincePeople's Republic of China
4. State Grid Shanghai Electric Power Research InstituteShanghai200437People's Republic of China