A novel parameter estimation method for permanent magnet synchronous motor drive

Abstract

This paper proposes a novel parameter estimation method for permanent magnet synchronous motor (PMSM) drive based on Hartley modulating function (HMF). The speed and torque of a PMSM depend on currents directly and winding resistance, inductance indirectly. So, in order to achieve a good performance drive system, an accurate knowledge of machine parameters is important. Most of the existing techniques for parameter estimation of PMSM use a linear model of the system in order to estimate the parameters. However, PMSM is inherently nonlinear, and linear modelling is applicable for restricted operating region. The proposed estimation is free from boundary conditions and gives rise to linear-in-parameters model. Using HMF method, electrical parameters such as armature resistance (Ra), q-axis inductance (lqs), d-axis inductance (lds) and mechanical parameters such as the moment of inertia (J), viscous friction coefficient (β) are estimated with a fair amount of accuracy. The estimates have been found to be quite sensitive to the choice of sampling time and size. The proposed method is verified by MATLAB simulation, and shows better performance in the estimation process.