Patent ID: 8947029
Filing Date: 2015-02-03
Classification: G01K,H02P

Abstract:
1. A method for ascertaining the rotor temperature of a permanent-magnet synchronous machine comprising: determining a first estimate (T R1 ) for the rotor temperature as a function of a remanent flux density of permanent magnets contained in a rotor of the synchronous machine, and determining a second estimate (T R2 ) of the rotor temperature by using a Kalman filter containing a thermal model of the synchronous machine, the first estimate (T R1 ) for the rotor temperature being supplied to the Kalman filter at least intermittently; wherein the first estimate (T wherein a steady-state model of the synchronous machine is used for determining the first estimate (T where U d , U q denote the voltage of synchronous machine in the d direction and q direction, respectively, I d , I q denote the current of the synchronous machine in the d direction and q direction, respectively, and L d , L q denote the corresponding inductances, where R is a strand resistance, ω is the electrical angular velocity and K m is a temperature-dependent fundamental-wave amplitude of the field-linked direct-axis flux.