A novel three-phase single-switch discontinuous-mode AC-DC buck-boost converter with high-quality input current waveforms and isolated output

In this paper, a new three-phase single-switch AC-DC flyback converter system is presented. The system operates in the discontinuous mode. The simple structure of its power and control circuit, low mains current distortion, and resistive fundamental behavior, as well as the high-frequency isolation of the controlled output voltage, have to be pointed out. Besides the analysis of the stationary operating behavior, the dependencies of the peak values, average values, and rms values of the device currents, and of the maximum blocking voltages across the power electronic devices on the circuit parameters, are given as analytic approximations. The theoretical analysis is verified by digital simulation