In this paper, a three-phase fault is simulated at the input of a three-level Voltage Source Converters high voltage Direct current (VSC-HVDC) converter switch and a pole-to-pole error on the DC side in Multi-Terminal Direct current (MTDC) system consisting of four stations connected to an alternating current network with a high voltage , where the recovery of the system was verified after the occurrence of the fault in both cases, the three-phase fault with earth and the pole fault with DC link Capacitor earthed and not earthed. Simulations were performed using MATLAB Simulink. The simulation was conducted on the electric power transmission network 400 kilovolts, which operates on alternating current in the Syrian Arab Republic, and the DESERTEC ±500 kV network in the part that connected with Syria (Lebanon, Jordan and Turkey), which uses direct current.