This paper presents a modeling, design and simulation of PV array emulator based on Switched Mode Power Supply which consists on an Interleaved DC-DC Buck Converter controlled by an adaptive PI controller, this system is generally used for the purpose of reproducing the electrical behavior of a PV module without needing the use of real PV panels which are very cost and require a large space besides their dependence on weather parameters of irradiance and temperature. For those reasons, the PV emulator has been proposed to overcome these limitations and allow researchers, engineers and manufacturers to carry out tests and experimentation on PV systems such as PV MPPT algorithms and connected PV inverters irrespective of environmental conditions change. The reason behind using interleaved topology is its ability to give a little amount of ripples and reduce conduction losses; in addition, it allows downsizing LC filters, which improves the transient response speed. Simulation results are given and discussed in order to verify the effectiveness of PV emulator system as well as evaluate its performances in terms of accuracy, speed, and overshoot limitation.