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

Here is Why You Need An Adapter

The outlet and plug type used in Cuba are A, B, C and L and in South Sudan are C and D. This is how they look like.

South Sudan

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

Type C

Type D

Cuba

In Cuba, outlets of type A, B, C and L are in use.

Type A

Type B

Type C

Type L