The work presented in this paper concerns the speed control of a Separately Excited Direct current Motor (SEDM) by use of a Maximum Power Point Tracking (MPPT) strategy applied to a Boost DC-DC converter. A PV generator is used for energy supply. The use of conventional PI controller for speed regulation is due to low steady-state error, low costs, fast control and simple structure. The MPPT is implemented by using Perturb and Observe (P&O) algorithm. The elaborated control strategy is validated for different solar insolation and speed levels, when the boost output voltage is fixed.