A sensorless control strategy of an interior permanent magnet synchronous motor (IPMSM) is a Sliding Mode Observer (SMO) with feedforward compensation. It is based on the d-q mathematical model of IPMSM and uses Lyapunov's stability analysis to guarantee the robustness of the rotor position estimation. The innovative design eliminates the need for mechanical sensors by generating rotor speed and position estimates from the back-EMF, which is extended in the αβ reference frame. A simulation was made in MATLAB/Simulink for a 0.75 kW IPMSM over a speed range of 200–1000 rpm. The results indicated a 67% reduction in the error of rotor position estimation (from 5.4° to 1.8°) and a 30% increase in settling time compared to traditional PI-based control. The method enhances the stability and the quality of the current regulation; at the same time, it keeps the parameter variation robustness.