Research on PMSM Control for Position Sensorless Based on Fractional PD Sliding Mode Observer

According to the phase delaying question of estimated rotor position angle in traditional sliding mode observer, using fractional order calculus theory and singular perturbation two-time-scale decomposition theory, making up the parameter designing rules of fractional order PD sliding mode observer, proposed position sensorless control strategy for permanent magnet synchronous motor based on fractional order PD sliding mode observer. On one side, taking fast time-varying subsystem of singular perturbation two-time-scale decomposition theory to establish fractional order sliding mode observer; on the other side, taking slow time-varying subsystem of singular perturbation two-time-scale decomposition theory to obtain parameter of fractional order sliding mode observer. The results show that the method could not only making estimated rotor position angle follow actual rotor angle, but also establishing a global compensating control strategy of estimated rotor position angle effectively.