A five level diode clamped rectifier with novel capacitor voltage balancing scheme

In this paper, a Diode Clamped Multilevel Topology operating in Rectifier mode is presented. A simple voltage control strategy is implemented in order to control the DC-link voltage at the output side of the rectifier. A Level shifted Carrier based Sine PWM or SVM techniques can be incorporated to generate switching signals to the devices of Five-level configuration. For Diode Clamped Converter if the number of levels increased beyond three, charge balance among the capacitors is a major issue. A simple charge balance circuit is analysed for 5-level converter and a new voltage balance control scheme is proposed for maintaining equal capacitor voltages. MATLAB based simulation results are presented for the proposed scheme along with the conventional scheme for comparison. The converter also works as High Power Factor Rectifier and draws sinusoidal supply currents with unity power factor.