Under the background of AC/DC hybrid power grid with "strong DC and weak AC", the safe operation of DC system has attracted more and more attention, especially the frequent action of discrete equipment in converter station. The frequent action of discrete equipment will reduce the service life of equipment and even cause equipment failure. Therefore, it is very necessary to fully consider the voltage and reactive power characteristics and control mode of converter station in the voltage control strategy of DC near area. On the basis of fully considering the voltage and reactive power characteristics of converter station and the control strategy of discrete equipment, this paper deduces the quantitative formula of voltage and reactive power sensitivity of rectifier and inverter under the typical control mode of constant power at rectifier and constant extinction angle at inverter. Under the DC control mode considering the correlation between the sending and receiving converter stations, the multi angle simulation analysis is carried out on the influence of the two main factors of DC transmission power and converter bus voltage on the action frequency of discrete equipment in the converter station, and finally the corresponding conclusions are drawn, which provides theoretical support for the subsequent research of AC and DC systems.

converter station;DC control mode;discrete equipment action frequency;sensitivity