On the effects of interharmonic distortion on static converters controlled by means of PLL systems

The effects of interharmonic distortion on static converters whose control is based on the use of PLL systems are analyzed. After some brief recalls on amplitude and phase angle modulation produced by interharmonic distortion and on basic PLL techniques, a sensitivity analysis aimed to show the performance of the presented PLL systems in presence of interharmonic voltages superimposed to the fundamental is conducted. Finally, a case-study on a very simple system in presence of a STATCOM converter is developed.