US 12,249,942 B2
System and method of extracting motor fault signature using sparsity-driven joint blind deconvolution and demodulation
Dehong Liu, Lexington, MA (US); and Varun Kelkar, Champaign, IL (US)
Assigned to Mitsubishi Electric Research Laboratories, Inc., Cambridge, MA (US)
Filed by Mitsubishi Electric Research Laboratories, Inc., Cambridge, MA (US)
Filed on Mar. 27, 2023, as Appl. No. 18/126,586.
Prior Publication US 2024/0333193 A1, Oct. 3, 2024
Int. Cl. H02P 29/024 (2016.01); G01R 31/34 (2020.01)
CPC H02P 29/024 (2013.01) [G01R 31/343 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A fault detection system for detecting faults of an induction motor operating at varying operating conditions indicative of varying load conditions, varying speed conditions or combination thereof, comprising:
a sensor device connected to a power cable of the induction motor, wherein the sensor device is configured to measure a stator current of the induction motor under the varying operating conditions via the power cable;
a memory configured to store a computer-implemented fault detection method;
a signal processor configured to perform steps of the computer-implemented fault detection method, wherein the steps comprise:
forming a stator current vector by sampling the measured stator current using on a sampling frequency according to time sequences;
reducing noise of the stator current vector using a minimum-variance (MV) beam forming method;
formulating a joint blind deconvolution-demodulation optimization problem based on the stator current vector of a steady operating condition, a response vector of the induction motor, a modulation vector of varying operating conditions, and a noise vector to satisfy the measured stator current vector with reduced noise;
estimating the stator current vector of the steady operating condition, the response vector of the induction motor, the modulation vector of the varying operating conditions, and the noise vector by solving the joint blind deconvolution-demodulation optimization problem;
extracting fault signatures from a clean stator current estimate vector, wherein the clean stator current estimate vector is generated by use of the estimated response vector and the estimated stator current vector;
producing a control command to a controller of the induction motor if at least one of the fault signatures is greater than a threshold and controlling the induction motor by transmitting the control command that causes the controller to reduce an operation speed of the induction motor to a safety level, otherwise producing and transmitting a normal command indicative of the normal operations of the induction motor to the controller.