# On-Line Partial Discharge Monitoring System for Switchegears Based on the Detection of UHF Signals
## Program Design of Online Monitoring System
### Upper Computer Software Design  
The upper computer software of the system is developed and designed based on Microsoft Visual Studio 2019. The system uses HTML, CSS, and JavaScript to complete the data transmission in the background and uses C# to complete the human-computer interaction in the front end. The upper computer program made by webform can save users from installation, people can check the running status of switchgears through a mobile phone or PC browser at any time, and when necessary, issue instructions to the data collector to change the functions of the working mode conversion and the alarm threshold of the equipment. The software uses a SQL server 2019 to establish the database. The data detected by the online monitoring system are continuously stored in the database through the cloud platform, and the historical data measured by the equipment are reasonably classified and stored. The operator can directly see the history of the abnormal situation of the equipment by reading the database on the upper computer. Figure 11 shows the structure of the software. Figures 12 and 13 show the selected software functionality interfaces. The login interface is shown in Figure 12a. Entering the correct account password in the login  
Figure 11: Software structure block diagram. Figure 10: The flow chart of the data sending program. window will lead to the homepage of the monitoring system shown in Figure 12b. The database for storing account information is stored in the table named \"sysUser\", and the stored data include user account number, user password, and user level. Level 0 means that the account is an ordinary user, and Level 1 means that the account is an administrator. It is possible to enter the system platform as shown in Figure 12c. The homepage of the monitoring system mainly consists of an electronic map, a calendar, bar charts, pie charts, and a scrolling information bar. The calendar, bar charts, and pie charts use the echarts control, which stores database data in an array and is called by a control function to display it on the web page. The scrolling information bar uses a function to trigger the generation of the form and the reading of data, the trigger interval is set to 3 s, and through CSS3 animation technology the text can scroll up. The system platform requires management personnel to access and adjust the monitoring system, such as adding, modifying, and deleting devices, modifying the alarm threshold of the system, and handling alarm events. Figure 12d is the equipment information interface, which can see the amount of equipment in different regions. Devices are divided by provincial and municipal levels, and by clicking on the coordinates you can view the specific parameters of the current device, including the name, number, location, coordinates, discharge amplitude, number of discharges, and other parameters of the device. The electronic map is designed based on Baidu map; by reading the latitude and longitude of all devices in the database you can print the coordinate points of the devices on the map. The real-time data interface, shown in Figure 13a, allows you to view the real-time waveform graphs of different devices, including parameters such as discharge amplitude, number of discharges, and so on. The waveform will change in real time with the update of data. The historical data interface, as shown in Figure 13b, allows you to view the historical data of different devices, and you can select the device you need to query in the drop-down box, as well as the start time and the end time, to view all the information of the device in this time period. Both the real-time waveform graph and the historical waveform graph are designed based on echarts, the horizontal coordinate is the array of saved time, and the vertical coordinate is the array of saved data. The abnormal data interface is shown in Figure 13c, through which you can view all data that exceed the alarm thresholds set  
Figure 12: Part of the software interface functions.