With the rapid development of large-scale, high-capacity, and high-voltage equipment, the operating conditions for electrical devices have become increasingly stringent. This has led to a gradual increase in equipment failure rates, longer downtime for troubleshooting, and significant economic losses. Statistics indicate that a considerable number of accidents in recent years in the power system are related to the overheating issues of electrical equipment. Therefore, monitoring the temperature of electrical devices has become particularly crucial. The temperature monitoring points for high-voltage electrical equipment are all situated in environments with high voltage, large currents, and strong magnetic fields, and some monitoring points are even in enclosed spaces. Due to issues such as strong electromagnetic noise, high-voltage insulation, and spatial limitations, traditional temperature measurement methods are no longer adaptable. Hence, online monitoring of the operating status of power equipment, fault diagnosis, and timely maintenance have garnered significant attention.

The Necessity of Wireless Temperature Measurement for Electrical Equipment

Generating plant (substation) switchgear, busbar joints, outdoor knife switches, and other equipment are all critical. Over time, due to aging, the contacts and busbar connections within the switches can experience excessive contact resistance, leading to overheating. These overheated areas are difficult to monitor, which ultimately results in accidents. Since the enclosed switchgear body is not to be opened during operation, it is challenging to measure the actual temperature of the contacts inside. Failure to promptly identify and address overheating defects can severely threaten the safety and production of electricity.

By utilizing wireless temperature monitoring technology, the supervisory software can record the real-time operating temperature of high-voltage equipment, saving it long-term in a database, and displaying the temperature change curve of monitoring points in real-time for analysis. If an excessively high temperature or a sharp rise to a pre-set alarm temperature threshold is detected, an immediate alarm is triggered. This provides cumulative data for the maintenance of high-voltage electrical equipment, enabling predictive maintenance for thermal faults.

Advantages of 2-Wire Temperature Measurement Technology

Due to the high voltage, enclosed nature, and continuous operation of high-voltage electrical equipment, its temperature measurement methods differ from those used for general temperature measurement. The wireless temperature measurement system boasts flexible configuration, stable operation, strong anti-interference capabilities, and low power consumption. This system primarily employs short-range wireless networking, with multiple temperature measurement terminals distributed around the wireless aggregation terminal. Within the effective communication range, temperature measurement terminals can be added, deleted, or moved at will. Operators can remotely monitor and receive early warnings about the temperature changes of electrical equipment under various harsh environmental conditions from the main control room, thus promptly grasping the operational status of the electrical equipment. Additionally, the wireless temperature measurement system's backend can display the entire temperature field distribution in the form of an electronic map, clearly identifying temperature anomaly points, identifying potential faults, and enabling the implementation of preemptive measures to prevent accidents.

Traditional temperature measurement methods either require manual intervention or are expensive, time-consuming, difficult to manage, and limited in scope. As a result, the distribution temperature monitoring system offers high cost-effectiveness and real-time performance. Given its ability to meet a wider range of needs, it will become an important means for monitoring temperature in high-voltage environments.

Application of 3-Wire Temperature Measurement Technology

The wireless temperature measurement system consists of wireless temperature measurement terminals, wireless monitoring terminals, wireless temperature concentrators, DTUs (Data Transmission Units), and a high-level temperature monitoring center, as shown in Figure 1. The wireless temperature measurement terminals are responsible for collecting temperature data from high-voltage switchgear; the wireless monitoring terminals are in charge of displaying and transmitting real-time temperature data; the wireless temperature concentrators receive and process data, then transmit it to the DTU via the RS-485 bus; the DTU converts serial data into IP data for transmission; and the temperature monitoring center handles the display, storage, analysis, and alarm of temperature data. This system enables the centralized and effective monitoring of the operating temperatures of moving and stationary contacts, joints, and busbars on multiple high-voltage electrical equipment within power plants (substations), significantly enhancing the operational reliability of high-voltage electrical equipment and effectively preventing the occurrence of electrical equipment fires.

4 Applications

Temperature monitoring suitable for power equipment in various industrial sectors such as ubiquitous power IoT, steel mills, chemical plants, cement factories, data centers, airports, power plants, coal mines, and substation transformer stations.

5 System Structure

Temperature Online Monitoring System Diagram

6 System Features

The Acrel-2000T temperature monitoring system is installed in the duty monitoring room, enabling remote monitoring of the operating temperatures of all switchgear within the system. The system features the following main functions:

1) Temperature Display: Shows the real-time values of each temperature measurement point within the power distribution system, and allows for remote data viewing via computer WEB or mobile APP.

2) Temperature Trend Curves: View the temperature trend curves for each temperature sensing point.

3) Operational Reports: Query and print temperature data at various temperature measurement points over time.

4) Real-time Alerts: The system can issue alerts for abnormal temperatures at various temperature sensing points. It features real-time voice alarm capabilities, enabling voice alerts for all events. The alert methods include pop-up windows, voice alarms, and can also send alert messages via SMS or APP push notifications, promptly reminding on-duty personnel.

5) Historical Event Query: Stores and manages records of events like temperature limits, enabling users to trace historical system events and alarms, facilitating query statistics and accident analysis.

7 System Hardware Configuration

The temperature online monitoring system is primarily composed of temperature sensors and temperature collection/display units at the equipment level, edge computing gateways at the communication level, and temperature measurement system hosts at the station control level, realizing online temperature monitoring of critical electrical components in the transformation and distribution system.

Conclusion 8

The application of wireless temperature measurement technology in cement enterprises effectively addresses the issue of timely inspections by old equipment, especially in critical areas where manual checks are impossible during equipment operation. By installing wireless temperature measurement devices, real-time monitoring of key areas is achieved, allowing for timely detection of problems and potential hazards, thus preventing power accidents and demonstrating great value for widespread promotion and application.