# Research on Power Cyber-Physical Cross-Domain Attack Paths Based on Graph Knowledge
## 4 Experimental Simulation Analysis
As the system load rate increases, for example, when the system load rate is 0.525, 0.617, and 0.689, the load loss of attack path 3 <v2,v8,v15,v17> is the highest. That is, at this stage, the protection equipment settings are maliciously tampered \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Number** & **Attack Path** & **Risk** & **Attack Process Description** & **System Status** \\ \hline
1 & \textless{}v1,v10,v11,v17\textgreater{} & 3.9 p & The protection equipment was attacked and shut down, and the power cutoff action did not take effect in time. & Cascading failures \\ \hline
2 & \textless{}v2,v5,v12,v17\textgreater{} & 2.11 & The attack control device issues erroneous instructions, causing malicious changes in power supply adjustment parameters. & Overvoltage \\ \hline
3 & \textless{}v2,v8,v15,v17\textgreater{} & 1.62 p & The setting value of the protection equipment has been maliciously tampered with, and the load switching operation & Load fluctuation \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Selected typical cross-domain attack path information. with, and the risk of cascading failures caused by misoperation or refusal to operate the load switching operation is the greatest. When the system load rate continues to increase, for example, when the system load rate is 1.4478 or 1.6387, the attack path 2 \(<\)v2,v5,v12,v17\(>\) has the highest load loss. The attack causes the control device to issue wrong instructions, causing the power regulation parameters to be maliciously changed, resulting in the greatest risk of cascading failures. When the IEEE-RTS79 system is used as the simulation analysis of the power grid physical space system, Figures 6 and 7 show the load loss and cascading failure probability of the power grid physical space system obtained when the system load rate is 0.6896 and 0.879. It reflects the relationship between the loss of load of the power grid's physical space system and the probability of cascading failure of the physical space system caused by the risk of cyber-physical cross-domain attacks transmitted across space through typical attack paths. The polyline in the log-log plot is the trend given by the simulation data. The following two conclusions can be drawn from the simulation results:  
1. When the system load rate is low, such as 0.6896, as shown in Figure 6, the overall cascading fault scale distribution of the power grid physical space system presents the characteristics of a ladder distribution. When a cascading failure of the same scale occurs in the physical space system of the power grid, the cyber-physical cross-domain attack risk is transmitted through the attack path 3 \(<\)v2,v8,v15,v17\(>\), and the resulting loss of load in the physical space system of the power grid plays a dominant role. 2. When the system load rate is high, such as 0.879, as shown in Figures 7 and 8, under the same system load rate, the physical space system load loss situation tends to be consistent. After cyber-physical cross-domain attack risks are transmitted across space through different attack paths, the probability of causing cascading failures of the same scale is basically the same. The figure shows that there are jump points at the end of the power grid physical space system load loss distribution chart, indicating that when the cascading failure of the physical space system develops to a certain scale, the entire network will collapse. This is determined by the network scale and structure of the system. For this simulation system, the internal lines and transmission sections of the two interconnected subsystems will be affected by the disconnection of certain lines, causing a large-scale collapse of the power physical system.