You Do Need power plug adapter while traveling from Sudan to Chad.

Here is Why You Need An Adapter

The outlet and plug type used in Chad are C, D, E and F and in Sudan are C and D. This is how they look like.

Sudan

In Sudan, outlets of type C and D are in use.

Type C

Type D

Chad

In Chad, outlets of type C, D, E and F are in use.

Type C

Type D

Type E

Type F