## 5 Establishment of a Real-Time Salt Contamination Monitoring System
### Monitoring System Webpage Planning  
This study proposes a monitoring system platform to assess the salt contamination or pollution level of insulators. The platform displays various parameters, including insulator leakage current and environmental parameters. This information assists maintenance personnel in gaining insights into the insulation condition of insulators, facilitating more efficient maintenance procedures.  
Figure 20 illustrates the planning of the monitoring system platform. The monitoring system is presented in the form of a visual webpage, with four main sections: (1) real-time weather parameters around the insulator, including pressure, temperature, relative humidity, wind speed, and ultraviolet (as shown in Figure 20); (2) the location of the insulator, including the tower's location, voltage level, and other relevant information; (3) insulator pollution levels, categorized as Normal, Warning, and Danger, and distinguished by different colors; and (4) the number of leakage currents above 0.5 mA and 1 mA (as shown in Figure 21).  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Output** & **Pollution Level** & **Section (30 min)** & **LCM (mA)** & **Pulse Number** \\ \hline \multirow{3}{*}{Strategy} & Normal & 30 & \textless{}0.5 & - \\  & Warning & 30 & \textgreater{}0.5 & \textgreater{}10 \\ \cline{1-1}  & Danger & 30 & \textgreater{}1 & \textgreater{}5 \\ \hline \end{tabular}
\end{table}
Table 6: The predicted leakage currents (LCMs) and pollution levels of the insulator.  
To validate the proposed monitoring system, this study employs the measured real-time weather parameters from 10:00 to 11:02 on 3 March 2019, as examples. The real-time weather parameters are shown in Figure 20.  
Subsequently, the prediction of leakage current and pollution level can be analyzed through the monitoring system.  
The leakage current is assessed using LSTM, calculating the number of pulses surpass 0.5 mA and 1 mA within a 30-min interval to analyze the pollution level. If there are more than 10 instances of leakage current pulses exceeding 0.5 mA within this period, it indicates a gradual deterioration in the insulator's insulation condition, causing the pollution level to transition from Normal to Warning. When there are more than five instances of leakage current pulses exceeding 1 mA within a 30-min interval, the pollution level of the insulator will change to Danger.  
Figures 21-23 illustrate the results of the prediction of leakage current and pollution level. It is evident that the leakage current gradually increases from 10:00 to 10:29, and the pollution level remains Normal during this period (as shown in Figure 21).  
Figure 21: Results of the prediction of leakage current and pollution level at 2019/03/03 10:00–10:29 (pollution level: Normal).  
Figure 20: The real-time weather parameters around the insulator.  
As the leakage current continued to rise, reaching 0.5 mA at 10:34, the situation escalated further. By 10:49, the instances surpassing the 0.5 mA threshold had totaled 15 within a 30-min interval, signaling a gradual deterioration in the insulator's insulation condition. Consequently, the pollution level transitioned from Normal to Warning (as shown in Figure 22).  
At 11:02, the leakage current persisted without a decrease, surpassing the 0.5 mA threshold 28 times within a 30-min interval, with 13 instances exceeding the 1 mA threshold. This indicates a severe pollution or environmental condition, increasing the likelihood of a flashover in the insulator string. As a result, the pollution level transitions from Warning to Danger (as shown in Figure 23).