Inverter nonlinearities and discrete-time vector current control

The authors study all-digital discrete-time vector current control loops containing a voltage-fed inverter in series with a permanent magnet synchronous motor. Normal operation of the typical pulse width modulating voltage fed inverter introduces nonlinear distortion into the voltage and the current waveforms of the motor. The authors consider both the causes and the attenuation of these disturbances using all-digital control. An effective, fully digital current controller is developed, and experimental results from a Motorola 68020 microprocessor-based system are presented