Harmonic analysis and control strategy of a three-phase three-level rectifier

The paper presents a control algorithm of the three-level rectifier in the three-phase voltage source converter, as well as a theoretical method for harmonic analysis of the input current rectifier. A control algorithm is based on the input current transformation into the d, q coordinate reference frame. The control strategy and harmonic analysis is considered in detail with the focus on the power factor correction and dc-link voltage estimation. The major advantage of using the three-level circuit is that the generated input current harmonics of the three-level rectifier are less than conventional three-phase diode bridge rectifier. The proposed control algorithm and theoretical method are verified by the computer simulation; the results are presented and discussed.