Hydrogen Energy paper 16

Abstract

Abstract. Vulnerable lines have serious impacts on large scale blackouts and cascading failures in power grid. With the integration of large scale wind power into power grid, both the topology structure and the distribution characteristics of power flow in power grid have undergone various changes, which leads great influences on the transmission line vulnerability. A comprehensive scheme to identify study transmission line vulnerability based on the weighted entropy analysis method is proposed in this paper. In this scheme, an assessment index, named incremental power flow entropy, is given firstly, which is used to describe the influence caused by variation of transmission lines themselves capability of carrying power flow transfer on lines vulnerability under the same aggregation level. And the other assessment index, named structural importance, is given to describe the structural changes of power grid caused by the integration of wind power. The two assessment indexes are then merged into one index by using entropy weight analysis method, which can assess the vulnerability of the lines from the two aspects of the power flow transmission and structural link. Vulnerability analysis under different situation, such as with and without the integration of the wind farm, the sharp fluctuation of wind speed in the wind farm, are carried out on the IEEE 39-bus system integrated with a 75MW wind farm, the simulation results verify that the proposed assessment index can not only identify the vulnerable line in power grid with wind farm integration, but also accurately reflect the vulnerability of the internal lines of the wind farm itself.