Summary: To prevent fires caused by high temperatures due to loose wire connections, aging cables, and other problems that can lead to enormous economic losses, reliable temperature monitoring and intelligent control of electrical systems are essential. Typical monitoring points include high-current cable connections, locally overheated areas of power supply systems, moving and static contacts in switchgear, input and output busbar connections, electrical contacts in rectifier cabinets, transformer connections, and critical electrical connections in substations or overhead lines. Our company's Intelligent Control Series products offer an effective solution for these situations.
Keywords: High-voltage switchgear; Intelligent control unit; Wireless temperature measurement
Overview
Equipment in substations, such as busbars, cables, and circuit breakers, operates continuously under high voltage and high currents. Temperature monitoring and maintenance of this equipment is essential for reliable grid operation. Heat dissipation is inherently poor, particularly in enclosed systems like high-voltage switchgear and gas-insulated switchgear (GIS). Manual temperature measurements do not allow for direct and continuous temperature monitoring of the components within the switchgear cabinets. Due to a lack of effective temperature monitoring and early warning systems, an increasing number of fires caused by overheated substation equipment have been reported in recent years. Such incidents significantly compromise security of supply, cause substantial financial losses for energy suppliers, and can even lead to personal injury or fatalities.
Lee & Man Paper has invested in four production lines for 5600/900 type packaging paper machines (PM23, PM25, PM26, and PM27) at its paper mill in Sepang, Malaysia. Average daily pulp production is 1,000 tonnes. The company's on-site power plant, which will supply the production lines, is currently under construction. The installation of the gas turbines for the second phase of the on-site thermal power plant includes two 30 MW gas turbines and the associated auxiliary equipment.
A stable and reliable power supply system is the foundation for business development. Therefore, the use of efficient, effective, and reliable temperature measurement technology for real-time online monitoring of heat-sensitive areas such as current transformers, busbars, cables, and switching contacts is of paramount importance. This enables the timely detection and alarming of temperature deviations, thus ensuring the reliable operation of substation equipment.
Product requirements and configuration
The project implements safety temperature monitoring, measurement, and control for 67 high-voltage cabinets in a thermal power plant, including input, voltage transformer, and output cabinets. Wireless temperature monitoring and intelligent control products are required. Detailed specifications are listed below:
- Dynamic simulation diagram, live display of high voltage and interlock control;
- Display of energy storage, voltage and acoustic misuse warning;
- Dual-channel automatic temperature and humidity control and display; communication cable length: 6 m;
- Remote/local control and switch operation (closing/opening);
- Control of the cabinet lighting;
- RS485/Modbus interface;
- Motion detection;
- Flashing pre-load indicator;
- Temperature measurement and display for electrical contacts; 6 temperature measuring points per high-voltage cabinet;
- Wireless transmission with self-contained power supply. Starting current ≥ 5 A; measuring range: -50 °C to 125 °C; integrated sensor and power supply module; service life ≥ 10 years; measuring accuracy: ± 1 °C;
- Real-time monitoring: Temperature sensors transmit temperature data to receivers in real time. These receivers forward the data to intelligent control units (upload frequency configurable), which in turn send the data to the background system to ensure real-time data acquisition.
In accordance with the above requirements, the wireless temperature monitoring products from Acrel were selected as shown in the following table.
Product solution list
On-site installation
Temperature monitoring system
Wireless temperature monitoring for electrical contacts in high/low voltage cabinets (local central display)
similar products
There are four types of wireless temperature sensors available: (a. Battery-powered type; b. Power harvesting type)
Conclusion
The ASD320 and ASD100G intelligent control units are new, multifunctional smart display units specifically designed for power distribution boards. They integrate numerous functions, including primary circuit display, switch status indicator, circuit breaker position, earthing switch position, spring accumulator status, disconnect switch status, voice alerts to prevent incorrect operation, high voltage indicator, wireless temperature measurement, high voltage interlock, automatic heating and dehumidification control, temperature and humidity control, heating fault indicator, and over-temperature warning. These features ensure safe and reliable electrical operation.