Package No. 4.1: Supply And Transportation Of Secondary Vttb And Configuration Of Kmt Power System At Transformer Stations: West Hanoi 500Kv Substation, Hiep Hoa 500Kv Substation, Truc Ninh 220Kv Substation, Phu Binh 220Kv Substation, Yen Thuy 220Kv Substation, Bim Son 220Kv Substation, Sam Son 220Kv Substation