A Method of Distance Protection Setting Calculation for AC/DC Hybrid Receiving-end Power Grid

In order to minimize the operational risk of the AC/DC hybrid receiving-end grid, a method of distance protection setting calculation considering DC operation safety is proposed in this paper. The characteristics and function of main protection and backup protection of AC power network are analyzed, based on which the contradiction between sensitivity, speed and selectivity of distance protection in AC / DC hybrid power network is analyzed. Although the widely used step by step coordination principle satisfies the sensitivity and selectivity, it can not satisfy the quick action and is easy to cause the DC blocking accident. Moreover, a simplified distance protection setting calculation method satisfying sensitivity and speed is proposed in this paper, which ensures the safe operation of DC and greatly reduces the operational risk of power grid. The effectiveness of the proposed method is verified by the actual example of Shandong power grid.