Vigorously developing renewable energy generation is an effective way to tackle the challenges of energy crisis and air pollution. High proportion of renewable energy integration will be one of the basic characteristics of future power systems. This paper summarizes a number of key issues for power systems with a high proportion of renewable energy generation from two aspects: the power system planning and operation under high level uncertainty and the stability mechanism of power system with massive integration of power electronic devices. On this basis

a theoretical research framework is proposed by dividing the above two scientific issues into five sub-problems: the evolution of power system structure and its forecasting model; a multi-objective planning method for AC/DC transmission network with a high proportion of renewable energy generation; the distribution system planning with a high proportion of renewable energy generation; the stability analysis of power electronics dominated power systems; the cooperative optimal operation theory of AC-DC hybrid power system with a high proportion of renewable energy generation. The relationship among the five sub-problems is described. Finally

key technologies for future power systems with a high proportion of renewable energy generation are provided and prospected.