A METHOD OF DETERMINING STATIONARY SIGNALS FOR THE DIAGNOSTICS OF AN ELECTROMECHANICAL SYSTEM

• Main Authors: ORMAN MACIEJ, OTTEWILL JAMES, ORKISZ MICHAL
• Format: Patent
• Language: English; Korean
• Published: 05.06.2014
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

The present invention is concerned with a method of determining stationary signals for the diagnostics of an electromechanical systems in which electrical rotating machinery is used and in which at least one electrical or mechanical signal is measured during an operation of the electromechanical system. The method is used especially for condition monitoring of electric motors and generators. The method consists of the following steps. €¢ Measuring an analog waveform signal ( S ) of the electromechanical system. €¢ Converting measured waveform signal ( S ) to discrete processed signal (S DP ) including vector of time instants and corresponding vector of amplitudes. €¢ Splitting the discrete processed signal (S DP ) into subdivided single periods (S DP1 , S DP2 , ..., S DPn ) where each of the subdivided single periods can include varied number of samples. €¢ Modifying number of samples for each subdivided single periods (S DP1 , S DP2 ..., S DPn ) by resampling procedure getting subdivided single periods after resampling (S DR1 , S DR2 , ... , S DRn ). €¢ Removing vector of time instants from each single period after resampling (S DR1 , S DR2 , ... , S DRn ) by a nondimensionalization transformation, getting subdivided nondimensional single periods (S DN1 , S DN2 ... , S DNn ). €¢ Concatenating all subdivided single periods (S DN1 , S DN2 , ... , S DNn ) into one nondimensional discrete signal (S N ). €¢ Transforming the nondimensinal discrete signal (S N ) into a dimensionalized stationary signal (S Nt ) by a dimensionalization transformation. €¢ Transforming the dimensionalized stationary signal (S Nt ) from time domain to frequency domain to obtain a frequencies spectrum, from which a vector of interest frequencies and corresponding vector of amplitudes are extracted to diagnose the electromechanical system.