The security boundary based planning idea and research scheme for the distribution system with high penetration of renewable energy generation are proposed. Firstly

the problems of the distribution network in China caused by integration of renewable energy generation are discussed. It is pointed out that the system security is the bottleneck limiting the high proportion of renewable energy generation while the security boundary

which is an effective way to break through the limitation

can describe the maximum operation range of a system when N-1 guideline is considered. Then

it has been found that the model

characteristics and mechanism of security boundary will significantly change in the scenario of high proportion of renewable energy generation: the range of security boundary will transform to a total-quadrant region from a single-quadrant region; the function and security characteristics will differ a great deal with an increase in penetration. Thus

it is necessary to determine the critical penetration rates which will cause essential changes of security. Finally

a security boundary based planning idea is proposed: 1)The network configuration will be selected based on the index of security boundary

such as shapes

and the controllable components

such as energy storage and active load

should be optimized. 2)The two planning methods for the scenarios of high-load density in urban area and rich renewable energy in rural area. 3)The generalized source-load index is developed by referring to the load ratio

to guide the practical planning. 4)New test system and simulation platform for distribution network planning is developed.