Dynamic VAR Configuration of Receiving-end Power Grid Based on Improved Trajectory Sensitivity Index

Transient voltage stability of DC receiving-end power grid is becoming more and more serious due to AC faults near inverters. One of the solutions is to configure the dynamic VAR compensation devices to provide dynamic VAR support for DC inverters. However, the influence of voltage sags is seldom considered in the existing compensation schemes. Based on this, this paper presents a synthesized configuration scheme for dynamic VAR for DC receiving-end grid. Firstly, the candidate buses for VAR compensation are determined by a static analysis method. Then, the improved sensitivity index of voltage and reactive power is proposed based on the transient voltage stability index with different weights for different voltage trajectory, which could consider the influence of different voltage sags. Then, based on these two indicators, a configuration method of dynamic VAR for DC receiving-end grid is proposed. Finally, the adaptability of the scheme is verified with a practical large scale multi-DC receiving end power grid, and the advantages and disadvantages of the scheme are discussed.