Ac Drive Motor Controller - Precor TRM10/GEN06 Service Manual

AC Drive Motor Controller

The Experience Line treadmills use an AC drive system to control a three
phase AC drive motor. In an AC motor, speed is controlled by frequency
independent of voltage or current and torque is controlled by the
voltage/current applied to the 3 windings. The windings (stator) and
rotor core of the motor are designed to spin at a specific speed at the
design frequency. This is by design of the motor itself. By changing the
frequency of the drive current, we can change the speed. The lower
control module generates the correct frequency to drive the motor at the
desired speed. Since the speed of an AC motor is controlled by frequency,
there is no need for a speed sensor.
Figure 7: AC Drive Motor Controller
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