Patent ID: 8228013
Filing Date: 2012-07-24
Classification: H02P

Abstract:
1. A motor drive system comprising: a motor control logic circuit providing and monitoring electrical signals communicated between a motor drive and a stator of a sensor-less PMSM, the sensor-less PMSM having a permanent magnet rotor having a magnetic direction and rotatable within the stator; a voltage pulse injector configured to execute in the motor control logic circuit to provide a plurality of voltage pulses; a current controller configured to execute in the motor control logic circuit to provide a plurality of voltage commands; a pulse width modulator providing the electrical signals to the stator as a function of at least one of the voltage pulses and the voltage commands; a selection module having at least two states and operative to selectively provide the voltage pulses to the pulse width modulator in a first state and the voltage commands in a second state; a commissioning program executing in the motor control logic circuit with the selection module in the first state to: (a) deduce rotor orientation by the application of the voltage pulses to the stator; and (b) employ the deduced orientation to apply at least one electrical signal to the stator along a q-axis of the rotor to measure q-axis self-inductance as a function of q-axis current and applying at least one electrical signal to the stator along a d-axis of the rotor to measure d-axis self-inductance; and a control algorithm executing in the motor control logic circuit with the selection module in the second state to operate the sensor-less PMSM as a function of the measured q-axis and d-axis self inductance.