**8. Conclusions**

This chapter is talking about the implementation and simulation of a small power system with a differential protection for the power transformer. The implementation is shown in step by step. This simulation is tested for various cases and for all cases it gave satisfactory results. All the tests gave satisfactory results. There are some difficulties are faced in the implantation of this system such as the lack of some toolbox in the Sim-power-system. For example, there is no current transformer in the toolbox. In this case, there are two choices to solve this problem. The first one is to use a regular single phase and make some changes in its specification to fit the current transformer specifications. The second one is to use a current measurement, but this one will not simulate the problems of the CTs.
