Field Oriented Control of Surface Mount Permanent Magnet Synchronous Machine with Non Linear Observer for Continuous Rotor Position Estimation

Abstract

Vector control of Permanent magnet synchronous machine (PMSM) is executed with the knowledge of rotor angle for stator commutation. The paper proposes a method to utilize the feature of obtaining continuous rotor position from the Ortega non-linear observer to be used in a Field oriented control of PMSM. In addition, the speed information is necessary for current decoupling in Field oriented control. The sensorless algorithm implemented also uses a Phase lock loop (PLL) to estimate the speed, instead of numerical differentiation. Unlike the passivity observers which can give only rotor positions, the implemented algorithm estimates continuous rotor angle and also the speed thus completely eliminating the need of encoders. The implemented observer algorithm is tested with a Field oriented controller for a 0.3 kW surface mount PMSM and tested in MATLAB/Simulink for its speed tracking capability under various operating conditions. The implemented control algorithm exhibited good tracking accuracies under almost all the operating conditions.