AFL Based SMO Control Scheme for Sensorless Vector Controlled PMSM Drive

The motor parameter, which is challenging to apply owing to the complex methodology, affects the majority of methods for estimating the rotor position of permanent magnet synchronous motors (PMSM). This paper proposed an advanced fuzzy logic based sliding mode observer (AFL-SMO) control scheme that results in accurate estimation of rotor position as well as improves the precision in motor speed measurement. The proposed SMO employs an error function based on a new switching function, which eliminates the need for the conventional SMO's low pass filter and angular compensators. The fuzzy logic helps in controlling the switching coefficient,
$\gamma$
of the proposed switching function, resulting in speed measurement accuracy. The attainable and stable criteria of the improved SMO are established using Lyapunov's theory. The entire system is simulated in the discrete time domain considering the various operating conditions. The results show that the system performs admirably with significant improvement in speed precision and its settling time.