Electrolytic capacitors are nowadays widely used as DClink for industrial Adjustable Speed Drives (ADS), however they present a lower lifetime with respect to other capacitor technologies. For this reason, there is the trend to replace electrolytic capacitors with film ones to increase the system reliability. In addition, film capacitors are characterized by a much smaller capacitance per volume with respect to electrolytic ones. Thus, the DC link capacitance can be drastically reduced, leading to the concept of slim DC link power converters. However, by decreasing of orders of magnitude the dc-link capacitance, resonances between the dc-link capacitors and the grid inductance can occur.