A SOFT-SWITCHED, HIGH-FREQUENCY RESONANT RECTIFIER AND CHARACTERISTICS OF THE CONTROLLED SYSTEM

In this paper, a high frequency and soft-switched ac/dc rectifier empl oying a series-type resonant circuit is proposed to obtain the sinusoi dal ac line current, Using the proposed rectifier, the high power fact or and low harmonic currents are obtained in the ac line, Furthermore, several advantages such as the high power density and wide output vol tage range can also be available, To regulate the output voltage of th e proposed circuit, the digital proportional-integral (PI) controller is used whose sampling time corresponds to the zero-crossing point of the ac line voltage, Including this controller, the model for the clos ed-loop system is developed in order to examine the stability and dyna mic characteristics. With this model, the gain of the PI-controller is determined by the pole assignment technique and the closed-loop dynam ics is investigated by the root locus plots, A good agreement is made between the simulated and experimental results.