Research on improving robustness strategy of grid cyber physical system considering spatial information

Abstract

Adding additional links can be recognized as an effective way to improve the robustness of grid cyber physical system (GCPS) against cascading failures. However, for a typical large-scale and across-regional GCPS, previous studies mainly focus on the network topology without considering the components/nodes spatial information. Therefore, to improve the robustness of GCPS without changing the existing connections, five different link addition strategies, considering spatial information and construction cost constraints, are proposed. Firstly, a spatial GCPS model is established, which consists of the spatial power system and the spatial information system with hierarchical structures. Among them, the spatial information system consists of the access layer (AL), the backbone layer (BL) and the core layer (CL) and its network nodes are divided into different layers according to their functions. Secondly, based on the spatial information system layer nodes functions and the spatial power system nodes attributions, five link addition strategies, AL-AL, AL-BL, AL-CL, Generators-CL (G-CL) and Loads-CL (L-CL), are investigated under two constraint scenarios. Thirdly, to verify our proposed five link addition strategies have better improvement effects, we compare them with the two existing excellent strategies, including low degree link addition strategy (LD) and random addition link addition strategy (Random). Finally, the statistical test results on the real 39-node power system and the IEEE 118 bus system show that our proposed link addition strategies not only effectively improve the robustness of GCPS, but also have better effects than LD and Random. More specifically, no matter whether GCPS suffered severe or slight attacks, the AL-BL always performs better when either fixed number constraint scenario or fixed length constraint scenario, and the improvement effects of AL-AL, AL-CL, G-CL and L-CL are exhibited as descending orders, respectively. These findings can help maintainers to improve the robustness of GCPS before attacks.