A Novel Integral Second Order Sliding Mode-Based Sensorless Control of Permanent Magnet Synchronous Machine

This paper proposes a novel integral sliding mode observer (NISMO) integrated with the second order sliding mode algorithm for sensorless vector control of permanent magnet synchronous motors (PMSMs). The proposed method aims to address two critical limitations of conventional integral sliding mode observer (ISMO): excessive speed chattering during transient states and compromised accuracy caused by discontinuous switching functions. The super-twisting algorithm represents a second-order sliding mode algorithm with optimal performance. By substituting the sign function in ISMOs with a continuous control law inspired by the super-twisting algorithm, the amplitude of speed chattering is significantly mitigated under no-load conditions. Furthermore, the proposed improved model can directly estimate the sinusoidal back-electromotive force (EMF), which suppressed high-frequency oscillations effectively, in the initial stage of rotor angle estimation, thereby enhancing the observation accuracy of rotor Angle. The method’s simplicity, reliability, and robustness are validated through MATLAB/Simulink simulations, demonstrating its superiority in both transient response and steady-state characteristics.