Inverter for controlling an electric machine without prior characterization

An inverter for controlling an electric machine, the inverter comprising:

• a switching circuit comprising a low-side switch and a high-side switch, the low-side switch and the high-side switching each having a control terminal and two switched terminals;
• a driver circuit for providing control signals to the control terminals of the switching circuit;
• an electronic data processor;
• a data storage device in communication with the electronic data processor;
• a control module stored in the data storage device, the control module comprising software instructions for execution by the electronic data processor, the control module comprising:
• an inductance estimator to estimate direct inductance and quadrature inductance associated with the electric machine based on a first set of equations that assume constant rotor resistance and constant magnetic flux;
• a torque estimator to estimate an observed torque associated with a rotor of the electric machine based a commanded direct-axis voltage and a commanded quadrature-axis voltage, where the observed torque is proportional to the observed power consumption of the electric machine;
• a pulse width modulation module for provided pulse-width modulated signals to the electric machine based on the commanded direct-axis voltage and a commanded quadrature-axis voltage;
• and
• a back-electromotive force module configured to determine an adjustment derived from an estimated, observed torque and a commanded torque.