Parallel Contactless Transmission of Power and Rotor Temperature of Electrical Machines via Magnetically-coupled Resonance and Capacitive Radio Frequency

High rotor temperature of electrical machines can cause a series of insulation failures. In serious cases, it will lead to system operation failure. However, under the condition of high-speed rotation of rotor, the conventional temperature measurement by means of embedded temperature sensor is difficult to be utilized due to the limitation of power and data transmission. This paper proposes a parallel contactless transmission strategy of power and data based on magnetically-coupled resonance and capacitive radio frequency technology. Electric power is transferred contactlessly by means of magnetically-coupled resonance, while the parallel contactless transmission of data signals is realized by means of capacitive radio frequency technology. The experimental prototype was developed and installed on a 22kW induction motor. The results show that the clear data signal can be received on the stator side without filtering to realize parallel wireless transmission of electric energy and rotor temperature data. The research results of this paper can provide a good technical scheme for contactless rotor temperature measurement of large and medium-sized electrical machines.