StandardOHASA 18001,GB/T 19001,ISO9001,GB/T 24001,ISO14001,GB/T28001,OHASA18001Experience±800kV Yunnan-Guangdong DC Ultra-high Voltage Transmission Line Project500kV Lugang-Zhenzhou Line ProjectThe Three Gorges Transimission and Transformation Project ±500kV Three Gorges-Guangdong Line±500kV Guizhou-Guangdong Line220kV..