| Abstract |
This paper presents a new approach to estimate the
resistive parameters of the equivalent circuit in inverter-fed
vector-controlled salient rotor permanent magnet synchronous
motors. The method is based on the particular two-values shape
of the loss power-vs.-current characteristic, when the motor is
operated at constant output torque, constant speed and variable
direct (d) current component. Such a profile allows to process
the standard current/power/voltage measurements with a
differential criteria, in order to minimize and theoretically
cancel out the effects of non easily quantifiable phenomena,
such as temperature, fundamental frequency, inverter feeding
and additional losses. The presented method allows the
contemporary estimation of the stator resistance and the iron
losses equivalent resistor. A particular feature is that the
resistive parameters are achieved in the practical operating
conditions in the constant torque region. In fact they are
identified near the minimum of the loss power-vs.-current
characteristics, which is close to the maximum torque-to-current
trajectory in the d-q currents plane. The paper covers the
illustration of the basic elements of the method, some issues on
the implementation problems, and the experimental results
achieved on a motor-drive system for city-scooter application,
which confirm the goodness of the proposal. |
