Transient performance analysis of a single-phase voltage-type PWM rectifier with active filtering function

The PWM rectifier investigated in this paper operates as a rectifier to supply DC power to its own load and at the same time, operates as an active power filter to supply to the AC line a current to compensate the harmonic current due to a nonlinear load connected to the same AC line. In this paper the transient performance of a single-phase voltage-type PWM rectifier with active filtering function is analyzed, by simulation, for the case when the DC load of the rectifier is changed suddenly. A method for generation of a modulation signal is shown which is appropriate both in the steady-state operation and during transient state of the PWM rectifier. Using this method, transient responses of the PWM rectifier in the case of a sudden change in its DC load are clarified. It is shown that the transient responses may become oscillatory and take a long time to settle down, depending on the value of a parameter of the rectifier circuit. A method to improve this is shown. Experimental investigations are carried out to justify the simulation analysis.