Research on the Integrated Control Strategy for Splitting, Paralleling and Tie-line Power Flow of Power Grid Based on Back-to-back VSC-HVDC

摘要

In order to improve the self-healing ability of the smart grid, a integrated control method which is of power grid splitting, paralleling and tie-line power flow control is proposed. The flexible AC transmission (FACTS) device which has been installed in power grid can be converted to a back-to-back VSC-HVDC grid-connected device by adding electrical equipment. Combined with the out-of-step splitting criterion and the control theory of unified power flow controller (UPFC),the interaction mechanism of grid disconnection, paralleling and tie-line power flow control is analyzed. The conversion circuit among the three operating modes is studied in more depth to achieve the mutual conversion of different operating states, which enhances the stability and recovery capabilities of the grid and improves the automation level of system. Finally, the system model is simulated in PSCAD/EMTDC and the results verify its feasibility.