# Power System Reliability Evaluation Based on Chronological Booth-Balieriaux Method
## 5 Conclusions  
Many power systems have prescribed probabilistic reliability standards to ensure the stability of a system. As the system becomes increasingly complex, a reliability evaluation method that adequately reflects the features of a power system should be developed.  
This paper proposed a deterministic reliability evaluation method considering chronological patterns by evaluating hourly reliability via LDC decomposition. In the proposed method, the hourly demand distributions reflect the characteristics of time-dependent generators in reliability evaluation. The resolution of the demand distribution is not limited to the \"hour\" and can be extended to arbitrary resolutions, which can accommodate time-varying generation resources with various frequencies. The proposed method reduced the computational load on the convolution operation to improve performance.  
The proposed method was validated by its application in the IEEE Reliability Test System 2020. The proposed method has accurate results, and this efficient convolution made the proposed method faster. This paper analyzed the effects of various chronological  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Iteration**} & **Peak Demand** & **LOLE** & **Reserve Margin** \\  & **(MW)** & **(Day/Year)** & **(\%)** \\ \hline
1 & 86,719 & 0.0000 & 31.31 \\
2 & 89,202 & 0.0000 & 27.66 \\
3 & 91,478 & 0.0001 & 24.48 \\
4 & 93,579 & 0.0021 & 21.69 \\
5 & 95,516 & 0.0173 & 19.22 \\
6 & 97,232 & 0.0746 & 17.12 \\
7 & 98,515 & 0.1740 & 15.59 \\
8 & 99,190 & 0.2522 & 14.80 \\
9 & 99,432 & 0.2850 & 14.53 \\
10 & 99,504 & 0.2952 & 14.44 \\
11 & 99,525 & 0.2984 & 14.42 \\
12 & 99,532 & 0.2994 & 14.41 \\
13 & 99,535 & 0.2998 & 14.41 \\
14 & 99,536 & 0.2999 & 14.41 \\
15 & 99,536 & 0.3000 & 14.41 \\ \hline \hline \end{tabular}
\end{table}
Table 10: Process for calculating the adequate installed capacity reserve.  
Figure 3: Adequate installed capacity reserve derivation flow chart.  
patterns, such as maintenance schedules and temperature. The reliability evaluation showed that chronological patterns significantly affect the reliability. In particular, the influence according to the maintenance modeling was outstanding. These results suggest that a reliability evaluation without considering chronological patterns may be unreliable.  
The proposed method was applied to determine the adequate installed capacity reserve in the Korean power system. This method can determine the AICR because it shows consistent results. The acceptable computational speed of the proposed method makes it competitive for use in the reliability evaluation of an actual large-scale system.  
Moreover, because the proposed method presents consistent reliability indices, the proposed method may be useful for policymakers who prefer accurate and consistent results. Hence, the method can be used to validate reliability evaluation algorithms using stochastic approaches.  
Although this study considers chronological patterns, it has the limitation of treating the pump as a traditional generator resource. Future research will consider the dynamic scheduling of a pump and ESS with fuel quantity (e.g., reservoir level and SOC) constraints in the reliability evaluation.  
Conceptualization, H.O.; Investigation, H.S.; Methodology, H.O.; Project administration, W.K.; Software, H.S. and K.K.; Validation, P.H.; Visualization, K.K.; Writing--original draft, H.O.; Writing--review and editing, P.H. and W.K. All authors have read and agreed to the published version of the manuscript.  
This research was supported by Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government (MOTIE) (20214000000140, Graduate School of Convergence for Clean Energy Integrated Power Generation).  
Not applicable.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.