Review on reactive power optimization of high proportion renewable energy power system

High penetration renewable energy connected to power grid intensifies the voltage fluctuation of grid nodes and brings great challenges to reactive power control of power system, while the integration of a mass of power electronics into the system significantly enriches the means of voltage regulation. In this paper, review and outlook on the reactive power optimization of high proportion renewable energy power system are presented. Firstly, the novel characteristics of reactive power control of the system are analysed from six aspects: source-load uncertainty, voltage stability, high penetration power electronics, demand-side flexibility, power market environment, and transmission and distribution integration. Secondly, the existing researches are introduced corresponding to these characteristics. Finally, the outlook of an overall research framework of the reactive power optimization covering time, space and target scales is proposed for the stable operation of the high proportion renewable energy power system.