Entropy-Based Grid Vulnerability Assessment on Sending-End Grid of UHVDCs with High Renewable Energy Penetration

Abstract

The UHVDC plays an important role to transmit renewable energy from the western energy base to the eastern load center in China. However, sending-end grids of UHVDCs are usually not strong enough and difficult to ride through the power flow transfer after DC failures, which significantly restrains the capability and efficiency of the UHVDCs. In conventional UHVDC planning and design, it is difficult to evaluate the strength of the topology of different planning schemes and figure out the preferable scheme. This paper proposes a grid vulnerability index based on the entropy theory. First, the transient potential energy and electrical betweenness method are introduced and a comprehensive vulnerability index is proposed. Then, considering that entropy reflects the uniformity of the system distribution, the grid vulnerability index is raised by calculating the entropy of all branch vulnerability indexes. An actual sending-end grid in China is evaluated to validate the effectiveness of the proposed method.