Wide-area Backup Protection for Substation DC Voltage Loss

In order to solve a series of problems such as protection refuses to operate and power system stability declines when the DC voltage of the substation is lost, this paper explains the huge harm caused by the loss of DC power in substations firstly, introduces the centralized wide-area protection system of substations and the DC system structure of 110kV substations commonly used in practical engineering. In view of the situation that the protection device and communication equipment lose power due to the loss of DC voltage in the substation, a wide-area backup protection method using channel alarm information to deal with DC voltage loss in substations is proposed. Then, based on the case analysis, the PSCAD/EMTDC simulation platform is used to build a power system model for simulation verification. The results show that the proposed wide-area backup protection method can operate effectively when the substation DC voltage is lost, and improve the ability of the power system to deal with special conditions.