Topological Analysis and Parameter Calculation of Transfer Breakers in Multi-Terminal HVDC System

The DC transfer switch is a key switching device that converts the DC operating current in the HVDC transmission system from one operating return line to another. In a multi-terminal DC transmission system, the selection of metallic return transfer breaker and the earth return transfer breaker is closely related to the system topology. This paper analyzes the multi-terminal HVDC transmission system and refines its topology characteristics. A calculation method for determining the configuration mode, parameter selection and operation sequence of the transfer breakers is proposed. This simulation verification is carried out in combination with a three-terminal HVDC project.