## 3 Case Study
### Dataset
\begin{table}
\begin{tabular}{l l l l l} \hline \hline
**No.** & **Data Field Name** & **Field Definitions** & **Operation** & **Input/Output** \\ \hline
1 & vid & Vehicle identification number & Deleted (Has no numerical & \\  & & sense.) & N/A \\ \hline
2 & yr\_modahrmn & Data acquisition time & Deleted (Has no numerical & \\  & & sense.) & N/A \\ \hline
3 & vehicle\_state & Vehicle status & Deleted (Is fixed value.) & N/A \\ \hline
4 & charging\_status & State of charge & Selected and used & Input \\ \hline
5 & mode & Operating mode & Deleted (Is fixed value.) & N/A \\ \hline
6 & speed & Vehicle speed & Deleted (Is fixed value.) & N/A \\ \hline
7 & gear & Gear level & Deleted (Is fixed value.) & N/A \\ \hline
8 & total\_volt & Total voltage & Deleted (Has a very high & \\  & & correlation.) & N/A \\ \hline
9 & total\_current & Total current & Selected and used & Input \\ \hline
10 & mileage & Cumulative mileage & Selected and used & Input \\ \hline
11 & standard\_soc & State of charge national standard & Selected and used & Input \\ \hline
12 & mode\_cell\_volt & Battery voltage plurality & Selected and used & Input \\ \hline
13 & mean\_cell\_volt & Average battery voltage & Deleted (Has a very high & \\  & & correlation.) & N/A \\ \hline
14 & max\_volt\_num & Maximum voltage battery number & Deleted (Is fixed value.) & N/A \\ \hline
15 & max\_cell\_volt & Maximum battery voltage & Selected and used & Input \\ \hline
16 & max\_volt\_cell\_id & Maximum voltage battery & Selected and used & Input \\ \hline
17 & min\_volt\_num & Minimum voltage battery number & Deleted (Is fixed value.) & N/A \\ \hline
18 & min\_cell\_volt & Minimum battery voltage & Selected and used & Input \\ \hline
19 & min\_cell\_volt\_id & Minimum voltage battery & Selected and used & Input \\ \hline
20 & max\_temp\_num & Maximum temperature subsystem number & Deleted (Is fixed value.) & N/A \\ \hline
21 & max\_temp & Maximum temperature value & Selected and used & Input \\ \hline
22 & max\_temp\_probe\_id & Maximum temperature probe & Selected and used & Input \\ \hline
23 & min\_temp\_num & Minimum temperature subsystem number & Deleted (Is fixed value.) & N/A \\ \hline
24 & min\_temp & Minimum temperature value & Selected and used & Input \\ \hline
25 & min\_temp\_probe\_id & Minimum temperature probe & Selected and used & Input \\ \hline
26 & sing\_temp\_num & Total number of single-cell temperature & Deleted (Is fixed value.) & N/A \\  & & probes & & \\ \hline
27 & mode\_cell\_temp & Individual cell temperature plurality & Selected and used & Input \\ \hline
28 & mean\_cell\_temp & Average individual cell temperature & Selected and used & Input \\ \hline
29 & max\_cell\_temp & Maximum individual cell temperature & Selected and used & Input \\ \hline
30 & min\_cell\_temp & Minimum individual cell temperature & Selected and used & Input \\ \hline
31 & max\_alarm\_lv & Maximum alarm level & Deleted (Is fixed value.) & N/A \\ \hline
32 & bat\_fault\_list & List of fault codes for chargeable energy & Deleted (Appears non-numeric.) & N/A \\  & & storage units & & \\ \hline
33 & insulate\_r & Insulation resistance value & Selected and used & Input \\ \hline
34 & dcdc\_stat & DC–DC status & Deleted (Is fixed value.) & N/A \\ \hline
35 & sing\_volt\_num & Total number of single cells & Deleted (Is fixed value.) & N/A \\ \hline
36 & alarm\_info & Universal alarm symbol & Selected and used & Output \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Data field names, field definitions, and operations. The fault data were screened out and more than 200 data volumes of 8 categories of fault data and 1 category of normal data were selected, totaling 9 categories of data to form the original dataset of the experiments in this study. The numbers of selected fault codes are shown in Figure 13b. In this study, the above nine fault codes are regarded as the classification problem of electric-system failure of EVs.