A 12-Pulse AC–DC Rectifier With High-Quality Input/Output Waveforms

This paper describes an ac-dc rectifier, which draws sinusoidal current waveforms from the utility. Also, it can supply either a ripple-free current or voltage to the dc load by using a dc filter. The technology involves an accurate shaping of the dc current by using two forced-commutated switches (IGBTs). The shaping of the dc current is reflected back into the shaping of the input currents, which become pure sine waves. The resulting system is reliable and able to handle rapid load variations with a simple and robust control system. It also operates under rectification and inversion. Detailed analysis and a complete set of experimental results from a 380-V 20-kVA rectifier system are provided.