Abstract:
An ultrasonic motor or USM uses mechanical vibrations of piezoelectric ceramic to be moved or
rotated. It exhibits several advantages over the conventional electromagnetic motor such as high
torque at low speeds, light weight, quiet operation and no electromagnetic interference (EMI). In
this thesis, the design of the two-phase half-bridge inverter with LLCC compensation is proposed.
In addition, the speed closed-loop control of USM modeled USR60-E3 is implemented by means of
the variable switching frequency method and the overall control algorithms for two-phase halfbridge
inverter and precise adjustment of switching frequencies are digitally implemented on a
TMS320F2808 DSP controller. From experimental results, the motor speed can also be successfully
tracked the reference speed with many speed profiles and load conditions.