With the wide application of large scale of wind power integration and multi terminal flexible DC VSC-MTDC

the traditional reactive power optimization cannot suit well AC and AC parallel operation system including intermittent wind farm. In this paper

a kind of reactive power optimization method of AC and DC parallel operation based on scenario analysis method including wind farm and VSC-MTDC. Firstly

the statistics of the history data of wind farm output is done so to match multi-scenario probability of the wind farm output

then the minimum of the expected value of comprehensive grid loss under the multiscenario is established as the objective function and reactive power optimization model of AC and DC system operation constraints（containing wind farm） of the control strategy of VSC-MTDC system and involved by VSC-MTDC is taken into account. The global optimal solver popt is adopted to solve optimal reactive power proposal under main and slave control mode and voltage sag control mode. Finally

the real Nanao regional grid of Guangdong is taken as an example for analysis

the effectiveness of the proposed method is verified through comparison of the optimization proposal under the master and slave control as well as sag control model of the single-scenario.