[1]State Grid Shandong Electric Power Research Institute;
Jinan 250002;
China;
[2]State Grid Zibo Electric Power Company;
Zibo 255000;
China;
[3]State Grid Shandong Electric Power Corporation;
Jin 250000;
Chin.;
[4]State Grid Dongying Electric Power Company;
Dongying 257100;
China;
[5]Zhongshi Yitong Group Co. Ltd.;
Jinan 250002;
China;