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.
The DC link is the connection between these two circuits. The DC link usually has a capacitor known as the DC link Capacitor. This capacitor is connected in parallel between the positive and the negative conductors.
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.