Signal processing system for overload relay or the like
Solid state circuit protection system and method
Electronic control system for overload relay or the like
Motor control apparatus with rotor heating protection
Electrical equipment protection apparatus and method
Generalized real-time thermal model
Ground fault voltage limiting for a locomotive electric traction motor
ApplicationNo. 269465 filed on 06/30/1994
US Classes:706/18, Association318/806, Condition responsive706/20Classification or recognition
ExaminersPrimary: Wieder, Kenneth A.
Assistant: Bowser, Barry C.
Attorney, Agent or Firm
International ClassesG06G 007/60
AbstractA method for detecting a departure from normal operation of an electric motor comprises obtaining a set of normal current measurements for a motor being monitored; forming clusters of the normal current measurements; training a neural network auto-associator using the set of normal current measurements; making current measurements for the motor in operation; comparing the input and output of the auto-associator; and indicating abnormal operation whenever the current measurements deviate more than a predetermined amount from the normal current measurements. The method models a set of normal current measurements for the motor being monitored, and indicates a potential failure whenever measurements from the motor deviate significantly from a model. The model takes the form of an neural network auto-associator which is "trained"--using clusters of current measurements collected while the motor is known to be in a normal operating condition--to reproduce the inputs on the output. A new set of FFT's of current measurements are classified as "good" or "bad" by first transforming the measurement using a Fast Fourier Transform (FFT) and an internal scaling procedure, and then applying a subset of the transformed measurements as inputs to the neural network auto-associator. A decision is generated based on the difference between the input and output of the network.