# Security-Oriented Cyber-Physical Risk Assessment for Cyberattacks on Distribution System
## 5 Simulation Results  
### Physical Consequence Calculation  
Simulation examples are performed on a distribution system for IEEE-RBTS bus 2 [37]. The physical network topology is shown in Figure 7. This test system consists of 4 feeders including 22 load units. The load type and its distribution is shown in Table 2. The other parameters such as load values, consumer numbers of load units, failure rate of feeder sections, and power outage time during FLISR are adopted from the literature [37]. The power outage time caused by a cyberattack in this simulation is modified from the literature [37], as shown in Table 3. There are 4 circuit breakers and 10 section switches, which are considered as the main attack targets. The calculation results of the physical consequences of attacking CB and SS are shown in Tables 4 and 5. It can be seen that the physical consequences of undesired tripping are as serious as those of failure to operate. Therefore, it is meaningful that we both consider the direct consequences caused by a cyberattack and the consequences of cyber-physical combined faults. Specially, feeder 2 only has SS and two feeder sections; we just need to consider load 8 when calculating the physical consequence of failure to operate. Thus, the value is relatively small. From Table 5, it can be found that the physical consequences of undesired tripping of SS, which is close to the feeder front, are more serious. The physical consequences of failure to operate of SS are determined by the load condition of the adjacent feeder section, such as the load value, consumer number, and consumer type. As usual, the physical consequences of adjacent switch misoperate of SS are more serious. During FLISR, the power restoration process of nonfault areas is affected because the actual physical fault is not removed. Thus, the fault areas are expanded even to extend to the adjacent transfer feeders.  
Figure 6: Research framework of quantitative security risk assessment method for cyberattacks on CPPDS.  
\begin{table}
\begin{tabular}{c c c} \hline
**Load Node** & **Customer Type** & **Load Level Factor** \\ \hline
1–3, 10–12, 17–19 & Residential users & 1 \\
4, 5, 13, 14, 20, 21 & Government agency & 4 \\
8, 9 & Industrial users & 3 \\
6, 7, 15, 16, 22 & Business users & 2 \\ \hline \end{tabular}
\end{table}
Table 2: Load type and level factor.  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Feeder Number \(f_{i}\)** & **Fault Location \(a\)** & \multicolumn{3}{c}{**Power Outage Time (hr)**} \\  & \(b=1\) & \(b=2\) & \(b=3\) \\ \hline \multirow{3}{*}{Feeder 1} & section 1 & 0.43 & 1.58 & \multirow{3}{*}{0.12} \\  & section 2 & 0.29 & 1.59 & \\  & section 3 & 0.23 & 1.59 & \\  & section 4 & 0.24 & 1.54 & \\ \hline \multirow{3}{*}{Feeder 2} & section 1 & 0.52 & 1.12 & \multirow{3}{*}{0.13} \\  & section 2 & 0.27 & 1.03 & \\ \hline \multirow{3}{*}{Feeder 3} & section 1 & 0.46 & 1.57 & \multirow{3}{*}{0.15} \\  & section 2 & 0.22 & 1.59 & \\ \cline{1-1}  & section 3 & 0.24 & 1.52 & \\ \cline{1-1}  & section 4 & 0.23 & 1.57 & \\ \hline \multirow{3}{*}{Feeder 4} & section 1 & 0.48 & 1.59 & \multirow{3}{*}{0.13} \\  & section 2 & 0.24 & 1.57 & \\ \cline{1-1}  & section 3 & 0.25 & 1.57 & \\ \cline{1-1}  & section 4 & 0.27 & 1.52 & \\ \hline \end{tabular}
\end{table}
Table 3: Power outage time caused by cyberattack.  
Figure 7: IEEE-RTBS bus 2 system.