An Online Monitoring System of Contact Temperature inside HV Switchgear Cabinet Based on Zigbee Wireless Network

An on-line monitoring system of contact temperature inside HV switchgear cabinet based on Zigbee has been studied and developed, which consists of the power monitoring center, the temperature monitoring unit and the temperature display unit. The contact temperature of switchgear is measured by DS18B20 of the temperature monitoring center which is designed based on CC2430, which is timely sent to the temperature display unit by Zigbee wireless communication. A current transformer CT installed conveniently on contact arm or bus is designed for producing an induced 9V~24V AC voltage, and a stable 5V DC voltage is obtained as the power source of the temperature monitoring unit by a rectifier and regulator circuit which is described in this paper. An interface of RS485 or CAN of the temperature display unit is designed to connect to the power monitoring center, and the corresponding temperature of different contacts or buses inside different cabinets can be broused and monitored remotely. The running results show that the system can work well and the temperature error is within plusmn0.5degC.