Motor Torque Measurement Using Dual-Function Radar Polarized Signals of Flux

Abstract

Motor Torque (MT) measurement plays a vital role for evaluating the performance of squirrel cage induction motor during operating conditions. Accurate and continuous measurements of MT provide information regarding driving load capacity, performance degradation of motor, reduces downtime and increases the efficiency. Traditional inline torque sensors-based measurement becomes inaccurate during abrupt change in load during starting condition of motor due to torque spikes. Mounting of torque sensor on motor is a major problem during torque measurement. Improper mounting of sensor acquires signals from other inefficient driveline components such as gearbox, couplings, and bearing. In this paper, we propose a non-contact method for MT measurement using dual-function ultra-wide band radar sensor and called as motor torque- design for reliability (MT-DFR) method, which measures torque through and air gap magnetic flux. Torque is orthogonal to air gap flux density. Air gap flux varies with motor speed, different load, and supply voltage. Dual-function ultra-wide band radar sensor signal reflect from Air gap flux and polarized. Polarized signals of Dual-function ultra-wide band radar process with multi-synchro squeezing transform (MSST) and obtain Instantaneous Frequency (IF) of air gap magnetic flux. MSST provides better representation of reconstructed signal with higher concentration for oscillatory electromagnetic waves. MT measured from IF of MSST and Gaussian process regression. Proposed method of MT measurement performs in different loading conditions such as such as no load, static and transient load conditions, and induced torque spikes. The proposed MT-DFR method predicts the torque with 98.10% accuracy compared to traditional method and ground truth verified.