公开(公告)号：US20210265835A1

公开(公告)日：2021-08-26

申请号：US17251274

申请日：2019-04-01

申请人： NR ELECTRIC CO., LTD ,  NR ENGINEERING CO., LTD

发明人： YEYUAN XIE ,  HAIYING LI ,  YU WANG ,  ZHONGFENG ZHANG ,  DONGMING CAO

IPC分类号： H02H9/02 ,  H02H1/00

摘要： A multi-voltage level direct current grid system and a control protection method, the direct current grid system comprising: at least two direct current buses; at least one direct current transformer, one end of which is connected to a first direct current bus while another end is connected to a second direct current bus or a lead-out wire, which may achieve direct current voltage conversion; and at least one lead-out wire current limiter, one end of the lead-out wire current limiter being connected to the second direct current bus while another end is connected to the lead-out wire; the lead-out wire current limiter comprises a first current-limiting unit, and the first current limiting unit comprises a group of direct current switches, as well as a first bypass switch and a first current-limiting resistor unit that are connected in parallel.