1. School of Electrical EngineeringShandong UniversityNo. 17923 Jingshi Road250061JinanPeople's Republic of China
2. Research Center of Smart GridsShandong University of TechnologyNo. 12 Zhangzhou Road255049ZiboPeople's Republic of China
3. Consulting departmentit4powerChollerstrasse 36300ZugSwitzerland
4. Department of standardizationSchneider Electric, 38HP4 Plant38050Grenoble Cedex 9France
5. School of Electrical Engineering and AutomationQilu University of TechnologyNo. 3501 Daxue Road250353JinanPeople's Republic of China