In order to reduce the voltage fluctuation caused by HVDC disturbance

and enhance the safety of grid connected wind turbines

on the basis of the control system simulation model of HVDC aiming to the practical engineering which was newly developed in PSD-BPA power system electromechanical transient simulation software

we analyzed the dynamic response characteristics of the main electric quantity of the HVDC system under the AC voltage disturbance at the rectifier side.Then we evaluated the effects of different AC voltage disturbance characteristics and HVDC controller parameters on the response characteristics

revealed the mechanism of overvoltage threat because of the reactive surplus of rectifier station

and put forward the relevant optimization measures.For the multi-HVDC transmission system

it was verified that the disturbance characteristics can be improved and the security can be increased by decreasing the magnitude of RAML

increasing the gain coefficient of current controller

and decreasing the boot threshold of VDCOL.