High Speed Motor Rotary Rotor Temperature Measurement Method

With the large-scale popularization and penetration of new energy vehicles, they have become a powerful engine for the development of the automotive industry. The temperature of high-speed motor rotor is the key data affecting the safety performance of the motor, and the rotor temperature detection has always been a difficulty in the testing industry. Taking high-speed motor of more than 10000rpm as an example, during high-speed rotation, the rotor of the motor is subjected to huge centrifugal force, high-speed friction between the motor rotor and the air gap, and the friction loss caused by the rotor surface is far greater than that of conventional motor. It brings great difficulties to the heat dissipation of the rotor. However, because the rotor is a high-speed rotating part and is subject to internal space restrictions, the current internal motor design stage in the industry mostly uses indirect temperature measurement means or wireless telemetry technology, high-speed slip ring technology and other test means to verify the motor design. However, there are many problems, the structure of the temperature measurement technology equipment components is more complex, the structure of the motor is greatly changed, the weight of the equipment produces a large centrifugal force, affecting the normal operation of the motor. There are industry pain points.

Technical introduction

The principle of surface acoustic wave temperature measurement technology is that surface acoustic wave components can obtain different reflection frequencies by changing their material properties, and are very sensitive to the physical parameters of the environment, so surface acoustic wave components are increasingly used as sensors, and are suitable for gas, pressure, force, temperature, strain, radiation and other fields. The temperature measurement system is a typical application of surface acoustic wave technology in the field of temperature. The technology sensor has many advantages, such as passive, wireless, high temperature resistance, maintenance-free and so on, and is becoming a research hotspot in the industry.

The processing unit of the surface acoustic wave temperature measurement system will generate a low-energy and high-frequency radar pulse. When the wireless temperature probe passes the fixed-point antenna in motion, the radar pulse is received. The probe surface reflector pulse responds back to the fixed antenna and is transmitted to the signal processing unit. Finally, the measured temperature value is calculated and transmitted to the monitoring system of the master computer. The temperature measuring system can realize the continuous real-time monitoring of the temperature of the electric rotor, and the structure is simple, and the running state of the electronic rotor can be effectively predicted and data analyzed.

Working framework of surface acoustic wave temperature measurement technology

The surface acoustic wave temperature measuring system consists of several parts: temperature sensor, reading antenna, reader and upper computer. The temperature sensor has a built-in surface acoustic wave resonator and transmission antenna, which is the sensing front end unit of the system temperature measurement, and is installed in the rotor temperature measurement part (mostly on the magnetic steel surface); The reading antenna is a wireless signal transmission channel, installed in the same space as the sensor, and maintain wireless isolation; The reader is responsible for receiving and reading the signal transmitted by the antenna, completing the analysis, processing and transmission of the sensor signal, and finally uploading it to the upper computer through the communication cable.

Sum up

According to the demand of automobile motor rotor temperature measurement in new energy industry, a rotor temperature measurement technology based on surface acoustic wave is provided. The problem of low temperature measurement in high speed rotating state of motor rotor is solved effectively. To solve the new energy industry motor or traditional internal combustion engine, compressor rotor bearing and other parts of the temperature measurement needs.