On the use of the maximum entropy method for the spectral estimation of PWM output signals

The fast Fourier transform (FTT) algorithm has always been an important tool for characterizing the frequency content of inverter output waveforms. As an alternative to the FFT, the parametric technique referred to as the maximum entropy method (MEM) is applied in the spectral analysis of the stator current of an inverter-fed induction motor under different operating conditions. With this method, windowing and interpolation techniques are not needed and a better frequency resolution is expected. Both the FFT and MEM methods are briefly reviewed and experimental results are provided