Distribution companies do not want to lose their customers in case of any supply failure. In this study, a 1600 kVA, 34.5/0.4 kV compact mobile substation, has been designed to be able to supply to customers in case the existing transformer fails in the real distribution system. A mobile substation that was in accordance with Turkey electricity distribution system standards was designed by creating a single line diagram and architectural drawing. It was modelled using the MATLAB/Simulink program with parameters taken by producers. Then, load flow and short-circuit fault simulations using a real power distribution system that consisted of nine pieces of medium voltage substation located in Istanbul were performed. Three-phase, phase to phase and phase to ground fault types were considered and carried out in the simulation. Simulation results showed that designed mobile substations could supply energy to the consumer and electrically protect them during any fault, maintenance or disaster. Substations provided the distribution of electricity by decreasing or increasing the voltage level. This study aims to find a novel solution to supply temporary energy in case of any fault situation in substations. Any fault that may occur in substations may cause a power outage or blackout in towns, villages, urban areas, cities or countries depending on protection selectivity. Mobile substation that can be transferred where needed provides a solution where a substation is off because of the fault. As a result of simulations, designed mobile substation, which is connected to the real distribution system, worked without any problem. This study can be very useful, especially for industrial applications.