Qdesys Sensorless Field Oriented Control Quick Start Guide
© Copyright 2012 Xilinx
29
Advanced Demo
Xilinx and Qdesys have a patent-pending method of advanced modulation, called Regenerative Pulse
Frequency Modulation (RPFM) that extracts more performance from the motor while simultaneously
reducing harmonic noise commonly present in traditional Pulse Width Modulation (PWM) methods. You
may demonstrate this mode with a few simple steps.
Switch between modulation profiles:
1. Turn the motor on and get it spinning in TRQ mode as described earlier
2. In the MAIN PANEL, choose
Advanced
PWM Control
3. Next to the
PWM Modulation Limit
dial you will find the radio buttons to toggle between SIN
(sinusoidal) and SVM (space vector modulation).
An overview of SVM techniques was presented in the Avnet X-
fest 2012 course “FPGA-based Motor
Control”. Essentially, SVM allows us to deliver a near-infinite variety of modulation profiles to the
motor phases. Simple PWM is the most basic form of modulation, however if we further modulate the
PWM signal we can deliver more elaborate voltage and current waveforms to the motor. Sinusoidal
modulation is one example; however SVM can further create more waveforms that are customer
tailored to a specific motor, system and application. The difference between SIN and SVM modes in
this demo can be observed in the
Whole Graphics
window as you switch between the profiles using
the
PWM Control
window.
