The simulation of large AC/DC power grid requires that the control and protection model of HVDC/UHVDC transmission is fully functional and accurate

and expects that the model will have a good simulation speed. A design method of control and protection model is presented based on the actual project and virtual device. Firstly

a method for constructing the logical structure of control and protection model is proposed

and the function of each level of virtual device is illustrated. Then

the principle of implementing a virtual device in the electromagnetic transient simulation software is described. Taking Lingzhou-Shaoxing UHVDC project as an example

the control and protection model is built in a variety of electromagnetic transient simulation softwares. The simulation results verify the accuracy and parallel computing ability of the model.