PWM rectifier using a time sequencing method in the current control loop

The bandwidth of the current control loop in high-power pulse-width modulation(PWM) rectifiers is increased by a time sequencing method for sampling,calculating and updating in the current loop.A high-speed microprocessor is used to eliminate the calculational delay in the current loop.However,the method imposes some limitations on the output voltage on the AC side,which degrades the capability to control the AC current while maintaining the DC voltage when the utility voltage increases significantly.With its tunable power factor,the PWM rectifier can absorb reactive power from the grid in this situation to compensate for the degradation.Test results show that the method significantly increases the current loop bandwidth and improves the PWM rectifier performance while controlling the reactive power.