Kaushal Vadnere
Ansys Employee

Hi Amir,

Voltage coupling is used to model the equipotential surfaces, edges, vertices. The Voltage Coupling links the behaviors of a group of geometric elements together. This means that the results calculated for one element of the group will apply to all elements within the group.
Refer to this Article in Ansys Help for more info on voltage coupling: 17.6.4.2. Voltage Coupling (ansys.com)