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

Here is Why You Need An Adapter

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

Palau

In Palau, outlets of type A and B are in use.

Type A

Type B

South Sudan

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

Type C

Type D