Konferensartikel

This work develops a 6-terminal low voltage DC grid to study DC grid under various scenarios or its interaction with AC system. In order to have the same physical characteristics as the high voltage practical project, this paper presents an equal capacity ratio principle to help the parameter design in low voltage DC grid. All the parameters are selected according to the parameters of the high voltage reference system based on equal capacity ratio principle and optimized by simulation model. Simulation models of original VSC- TDC and 6-terminal low voltage DC grid are built in PSCAD/EMTDC to validate the equal capacity ratio principle and the simulation results prove the equivalency. Based on the voltage margin control, a coordinated master-slave control method is proposed. The performance of the 6-terminal DC grid is studied under a variety of faults, simulation results proves that the DC bus voltage of the DC grid can be controlled steadily after faults.

DC grid; equal capacity ratio principle; voltage coordinating control; simulation model