Exact inverter waveform analysis using Z-transform estimation techniques

Z-transform approaches do not intrinsically trade off amplitude vs. frequency accuracy, as do Fourier-transform approaches. Thus, exact measurement of both quantities for the relevant harmonics is theoretically possible. However, existing Z-transform estimation methods fail in such applications because of their sensitivity to the colored, nonGaussian noise present in most inverter topologies. An approach to Z-transform estimation is presented that is very insensitive to such colored noise. The approach is developed theoretically and experimental verified on a PC-AT-based signal acquisition system using actual inverter waveforms.<>