Control of a three-phase PWM rectifier using estimated ac-side and dc-sidevoltages

A new control method of a pulsewidth modulation (PWM) rectifier without mea suring ac- and de-side voltages is proposed. rls information about these vo ltages is necessary for the controller, all required voltage values are est imated from the measured line currents and the calculated values of the inp ut reactor voltage during switching of the rectifier circuit. The input rea ctor voltage can be obtained by using a differentiator that produces the de rivative of the Line current or by detecting the voltage induced in a secon dary winding wound on the input reactor, The secondary winding creates the electric isolation between the main circuit and the controller, The propose d method is verified bg experiment. This paper describes the estimation met hod, gives the configuration of the controller, and discusses steady-state and transient performances of the rectifier.