Magnet Operating Point Estimation Using Flux Linkage Observer and Magnetic and Thermal Equivalent Circuit in PMSM

抄録

In this study, an effective combination of methods to estimate the magnet operating points in a permanent magnet synchronous motor (PMSM) is proposed. First, the magnet temperature estimation is compensated with the initial temperature and magnet loss based on the error between the estimated temperature obtained using the thermal equivalent circuit and the estimated temperature obtained using the flux observer. In addition, stator loss is compensated based on the error between the measured temperature and estimated temperature obtained using the thermal equivalent circuit. Then, the flux linkage observer is compensated with the d/q inductance value using the magnetic equivalent circuit. A method of estimating the magnetic flux density of a permanent magnet is designed to estimate the magnetic flux density of the motor using a magnetic equivalent circuit reflecting the value of the measured magnet temperature and magnetic flux density in the permanent magnet's B-H curve. Unlike the rotor temperature, the stator temperature can be easily measured, and the magnet operating point estimation can be designed as a more accurate and error-resistant estimation method. Furthermore, simulation and experimental verification demonstrate the effectiveness of the proposed method.