A Simple Proportional Resonant Current Controller with Floor Function Modulation Strategy For a Three-Phase, Three-Level Reduced Component Count Based Active Front-End Converter

In literature, most of the authors have discussed the concept of a 3-phase two-level active front-end (AFE) converter with different control techniques. Generally, concerning circuit configuration, the 2L-converter is very simple but has many disadvantages when considering high power with medium voltage applications. To alleviate the drawbacks of 2L-converter, there are different types of multilevel topologies have been reported and these have a greater operating voltage in conjunction with low voltage blocking semiconductor devices. In this paper, by considering the recently developed reduced component count (RCC) based on a three-level topology, the AFE operation has been explained. The AFE operation includes the objectives of regulation of DC bus voltage with low ripple, sinusoidal input source current with low harmonic distortion, unity power factor (UPF) operation at input source terminals, and regenerative operation. To achieve all these objectives, a simple proportional resonant (PR) current controller with floor function (F2) modulation strategy has been proposed and of course, it is well-suitable to different types of AFE-based multilevel topologies. Both transient state and steady-state analysis results of the RCC-based 3P3L-AFE converter have been elucidated vividly with the utilization of the PLECS platform.