BLDC Transfer Function Inductance Value
A FOC control implements two PI controllers Q-Torque and D-Excitation. If there is no field weakening contrl, then the setpoint of d-axis is zero, because we don't want any additional flux in the rotor direction. The rotor itself is a permanent magnet that gives the excitation magnetic field.

The q-axis is responsible for torque. Here the similarity of brush DC comes into a play. 

For six step control the hall sensors determine the switching sequence, so that stator magnetic field is almost at right angle with rotor magnetic field. The FOC with two PI controllers makes this even more precise, but for a good approximation let's say that six step method also keeps the right angle. Therefore, the inductance that the source will see it's dominantly the Lq.

You have to be aware that these inductivity could be refered with different methods. Can be a phase to neutral or phase to phase. 

For your setup the valid La shall be the inductance of phase to phase when the rotor is locked at 90 degrees electrical angle from d-axis. The Ra shall be the phase to phase resistance.

You may find some details how to measure Lq and Ld, but pay attentiton if L is phase to phase or phase to neutral.

Determine PMSM parameters