SYSTEM FOR REMOVING SPURIOUS SIGNATURES IN MOTOR CURRENT SIGNATURE ANALYSIS

A method for removing spurious signals in a process of motor current signature analysis of an electric motor includes creating an electronic model of the motor, acquiring simultaneous measurements of voltage and current at the motor, applying the voltage measurement to the motor model and determining an equivalent current produced in the model by the applied voltage, subtracting the equivalent current from the current measurement to produce a corrected motor current, and processing the corrected motor current through motor current signature analysis. For an ac motor, the method includes extracting signals corresponding to the fundamental excitation frequency from the voltage measurement to produce an interfering voltage, processing the interfering voltage through the motor model to produce a corresponding spurious current signal, and subtracting the spurious current signal from the measured current to produce to produce the corrected motor current signal for analysis.