Study on the Influence of VSC-HVDC on Receiving Power Grid Voltage Stability Margin and Improvement Measures

In this paper the mechanism of VSC-HVDC connection system is introduced. By means of construction two area small systems with VSC-HVDC connection in PSD-BPA electromechanical transient simulation software, the influence of different control mode on voltage stability margin is researched when the load in the receiving grid increases. The migration trajectory of the system running point on the PV curve is analyzed and the change rule of voltage stability margin in receiving-end power grid is revealed when VSC-HVDC transmit different active power and reactive power. Finally, the control measures to improve static voltage stability margin and dynamic recovery characteristics are put forward. The effectiveness of the control effect is verified by actual power grid.