Design of Wireless Micro-temperature Sensor System for Measuring Inductor Temperature

Inductors are the key components in power electronic converters, and their temperature is an important indicator to identify the normal or abnormal operation of the converter. Traditionally, temperature sensors embedded in the inductor require the transmission lines for power supply and signal feedback, which not only impacts the layout of the converter but also introduces electromagnetic noise into the measurement results. This paper thus proposes a complete wireless micro-temperature sensor system for the inductor in the power electronic converter, which not only harvests electrical energy directly from the magnetic core of the inductor, but also transmits the temperature data by the radio frequency wireless way. Design and working principle of the system are explained in detail, a prototype based on flexible PCB and System in Package (SIP) technology is built and experimental results are given to prove the feasibility of the idea.