High-penetration renewable energy system and AC/DC hybrid network are two main basic characteristics of future power systems. Evaluating different network's structure adaptability

especially for AC/DC hybrid network

is extremely important for power system to keep economical

safe

reliable and flexible when renewable energy and load both have an increasing trend of uncertainty. However

it is very difficult to evaluate the adaptability quantitatively

so that new indexes considering high-penetration are badly needed. First

this paper analyzes the basic characteristic of network structure and gives the definition of adaptability in the background of strong randomness. Then several probable indexes of structure adaptability are proposed based on the basic characteristic of adaptability. After that

a practical calculation method is put forward

which uses the Monte Carlo simulation and the optimal economic model. Finally

by using the IEEE 30-bus system as the basic network frame

an AC network and an AC/DC hybrid network are respectively evaluated

and different influencing factors of adaptability are researched to find the change regulation. The examples prove that the adaptability index can effectively reflect the adaptability of different transmission network structures with high-proportion renewable energy integration.