Research on Non-Communication Control Strategy for High/Low Voltage Valve Groups of UHVDC Transmission System Based on Site-Division Construction

This paper focuses on the site-division construction scheme of the Jinshang-Hubei UHVDC transmission project and studies the main circuit topology and operational control characteristics of the system. Based on the cascaded topology of the sending-end sub-stations, the voltage balance control method for high/low voltage valve groups in the sub-stations in introduced. By analyzing the dynamic response characteristics of high and low voltage valve groups under the no-communication coordination mode, the differences in fault response between this mode and the conventional control strategy are revealed. On this basis, a control strategy for high/low voltage valve groups that is suitable for the non-communication operation scenario is proposed, effectively improving the fault transient characteristics of the system. An electromagnetic transient model of the site-division UHVDC transmission system is established on the PSCAD/EMTDC platform to simulate and verify the fault characteristics of high/low voltage valve groups and the proposed control strategy.