Design and application of a passive RFID tag-based temperature measurement system with a communication range of 100 m

Abstract Passive radiofrequency identification (RFID) tag-based temperature measurement technology has emerged as a critical tool for monitoring the operational temperature of electrical equipment. Nevertheless, existing solutions are constrained by limitations in both measurement accuracy and communication range. In this work we develop a passive RFID temperature sensing system featuring a 100 m communication range and enhanced precision. A dynamic LC impedance matching circuit is designed, and the voltage reference circuit is optimised. We also propose a low-power signal reception circuit and develop a novel transceiver-separated RFID reader architecture. Simulations and experimental validation confirm a maximum temperature measurement error of 0.29 °C across the 20 °C–80 °C operating range. Field tests conducted in a substation demonstrate that the communication distance is up to 203 m with a temperature measurement error as low as 1.01 °C. This research not only addresses the technical gaps of existing solutions but also provides robust technical support for the development of digitalised power systems.