Comparison of torque estimation methods for interior permanent magnet wind power generator

Abstract

Control reliability of interior permanent magnet generator (IPMG) depends on accurate knowledge of the generator outputs (torque, currents etc.) and model parameters (resistance, inductances etc.). These outputs and parameters can be obtained by measurements or can be estimated. Reducing measurement equipment, cost of the control system is reduced as well. On the other hand, if control system contains accurate estimation algorithms, control reliability tends to increase. In this paper, comparison of the three torque estimation methods is done. First method considers the IPMG torque estimation using cross product of the IPMG flux and current vectors in the αβ reference frame. Second one estimates the IPMG torque also as a cross product of the IPMG flux and current vectors, but in the dq reference frame. Third method is based on generator electrical power and shaft speed. All of the mentioned methods are experimentally compared to the measured IPMG torque.