A DC link is a connection which connects a rectifier and an inverter. These links are found in converter circuits and in VFD circuits. The AC supply of a specific frequency is converted into DC. This DC, in turn, is converted into AC voltage.
![DC Link](https://1.bp.blogspot.com/-hr-FWeHC2bQ/VOXQ1ycBlVI/AAAAAAAAIc0/k_ciX2K15iY/s280/DC%2Blink.gif)
The DC capacitor helps prevent the transients from the load side from going back to the distributor side. It also serves to smoothen the pulses in the rectified DC.