Pole-placement control of voltage-regulated PWM rectifiers through real-time multiprocessing

The voltage-regulated pulse-width-modulated (PWM) rectifier is prone to instability. The system can be stabilized by proportional-plus-integral feedback control, but its transient response is slow. The authors describe results of a study of digital control to improve the system dynamic response by pole placement through state feedback. The control algorithm is implemented for real-time operation by using a custom-designed system of three high-speed microprocessors. Results from an experimental study with a 1 kW hardware laboratory model of the PWM rectifier show that the dynamic response can be significantly improved even when the DC link capacitor is substantially reduced.<<ETX>>