The goal of the model is to find how the motor characteristics depend on the switching angle. The
switching angle is the angular difference between a real switching event and an ideal one (at the point
where the phase-to-phase Back-EMF crosses zero).
The motor-drive model consists of a three-phase power stage plus a brushless DC motor. The power for
the system is provided by a voltage source (Ud). Six semiconductor switches (SA/B/C t/b), controlled
elsewhere, allow the rectangular voltage waveforms (see Figure 2-2) to be applied. The semiconductor
switches and diodes are simulated as ideal devices. The natural voltage level of the whole model is applied
at one half of the DC-Bus voltage. This simplifies the mathematical expressions.