The significance of Power Quality (PQ) continues to increase in the distribution networks in industrial and commercial zones. The disturbances present in the supply voltage are dangerous to the sensitive equipment like Adjustable Speed Drive (ASD). The power components of the ASD can be split into three sections - rectifier, DC link, and inverter. In this study, the DC link of the ASD is targeted. A systematic analysis of the impact of supply voltage disturbances (unbalance, harmonics, and fluctuation) on the DC link elements has been carried out in this work. The presence of supply voltage disturbances has been found to create stress on the DC bus capacitor and could lead to the consequent impact of lifetime reduction. It is identified from this study that the existing measuring indices of some of the PQ disturbances do not correlate monotonically with the extent to which the capacitor current is impacted. Therefore, new indices are proposed in this study. Further, to overcome the impact of these PQ issues and to develop a robust ASD, the study proposes a few solutions. The presentation will include the following: (i) identification of dominant disturbances, (ii) impact analysis of supply voltage disturbances on DC link capacitor, (iii) proposal of new indices for impact quantification, and (iv) proposal of solutions to mitigate impacts.