In this paper, we present the singular perturbation for decoupling a permanent magnet synchronous machine that deals with a separation of the variables in disjoined subset or two separate models: one having a slow dynamics, and the other a fast dynamics. The control speed and the Id current are carried out by sliding mode regulators. A qualitative analysis of the evolution of the principal variables describing the behavior of the global system (PMSM-Inverter (PWM) -Control) and its robustness is development by several tests of digital simulation