An AC motor is an asynchronous motor. That means the turning field is faster then the motor is actually spinning. A DC motor (including the LORENTZ ECDRIVE DC brushless motor) is a synchronous motor, this means that the turning field must be in sync with the position of the turning magnets on the rotor of the motor.
To achieve this in a DC motor very fast and precise detection of the motor rotor position in relation to the wiring set is required. In the LORENTZ design this is achieved without having any electronics inside the motor and with over 1,000 m of cable length.
The LORENTZ DC motor is regulated. Each time the magnets get into the right position of the next wiring set the PS Controller gives power to the next wire set. This is a highly dynamic and very fast process. The screenshot attached shows the typical signal that goes to the motor, this is a regulated signal produced by the PS controller which has infinite control unlike a AC motor.
This level of accuracy and control is another reason that LORENTZ ECDRIVE motors perform so efficiently and reliably for direct solar connection.