For their status of a new generation of HVDC transmission technology，the voltage source converter（VSC）and pulse width modulation（PWM）controlled-HVDC has wide application prospects.Following the Shanghai Nanhui wind farm accessing demonstration project，Dalian VSC-HVDC project with maximal transmission capacity will be put into operation in2014.In order to ensure the successful implementation，a detailed analysis of the influence after VSC-HVDC incorporation is in order.In the environment of electromechanical transient simulation program widely applied in China，the model and algorithm of VSC-HVDC transmission system are developed and verified by comparing with the electromagnetic transient simulation calculation.In light of the typical operational mode of the hybrid system，the influence of AC grid fault at the sending and receiving end，DC control mode and different controller parameters on the recovery characteristics is studied.The conclusion provides a technical support for the secure and stable operation of VSC-HVDC transmission system and AC/DC equipment.