Research on reliability assessment and multi-time scale improvement strategy of electricity-gas integrated energy system under cyber attack

While the coupling between various energy systems is deepening as integrated energy develops quickly, security risks in the information network system will be introduced into the physical system, and the interaction between the systems causes the security risks to increase. It is essential to maintain the multi-energy coupling integrated energy system’s safe and reliable operation. Therefore, this paper first constructs the cyber physics system (CPS) model based on the electricity-gas integrated energy system (EGIES), the fault propagation mechanism of the system caused by the cyber attack is analyzed, and the cyber attack scenario simulation method based on the N-n predicted fault set is proposed. Secondly, based on the optimal load shedding model and the reliability assessment index, the reliability assessment method of the electricity-gas integrated system under cyber attack is proposed. Then, on the basis of system reliability assessment, a multi-time scale reliability improvement strategy based on branch power and pipeline flow optimization of EGIES under cyber attack is proposed. Finally, the simulation results of the IEEE57-NGS20 electricity-gas integrated system verified the effectiveness of the proposed method. The proposed optimization strategy reduces the out-of-limit range of power transmission lines and natural gas pipelines, reduces the probability of cascading failure in the system under information attacks, and improves the resistance and energy supply reliability of the system against cyber attacks.