Power-Hardware-In-the-Loop (PHIL) simulation is an advanced tool for testing of power devices as it is a combination of simulation and hardware testing. Determining the Power-Hardware-In-the-Loop closed-loop stability is an issue of utmost importance in order to safely and repeatedly conduct PHIL experiments. In this paper several methods to determine the stability are presented and compared. These methods include both theoretical stability criteria and dynamic simulation results. Moreover, the two most popular methods for determining the PHIL accuracy from literature are presented and compared.