Novel High-Power Cascaded H-Bridge Multi-Level Rectifier

Cascaded full-controlled H-bridge multi-level rectifier canceled line-frequency phase-shift transformer which used in the input of traditional cascaded power unit multi-level rectifier. It have attracted significant research in power electronics and power transmission as a result of the superiority of its high power factor, low voltage devices needed, two-side power flowing,modular, etc. However, on one hand, the main circuit topology of such rectifier requires more switching devices, has huge circuit loss, control circuits and algorithm complexity; on the other hand, many loads such as water pumps and fans, requires only one-side power flowing and high power applications. The devices of its topology does not all require full-controlled devices. This paper presents two topologies of cascaded diode H-bridge multi-level rectifier, and on the basis of its detailed analysis and in-depth research, this paper presents a topology of hybrid cascaded multi-level rectifier, while further research of the topology of hybrid cascaded multi-level rectifier is discussed.First, on the basis of in-depth analysis of cascaded full-controlled H-bridge multi-level rectifier and cascaded diode H-bridge multi-level rectifier which have been proposed, this paper proposes a topology of diode H-bridge cascaded BOOST multi-level rectifier. After analyzing the circuit working principles, this paper establishes the steady-state mathematical model of the circuit,thereby the influence factors for the normal operation such as the boost inductance, unbalanced load, voltage balance control constraints were discussed in depth. The simulation of the control strategy corresponding to topology is adopted, and the topology and control strategy are proved to be the principle. On this basis, this paper created the experimental platform of diode H-bridge cascaded BOOST multi-level rectifier, completed the text and related experimental research on the experimental platform, and the experimental results strongly demonstrated the validity of research results.Secondly, on the basis of proposed topology of diode H-bridge cascaded BOOST multi-level rectifier, this paper proposed new topology of cascaded diode H-bridge multi-level rectifier which inductor is put forward. After introducing the working principle of the circuit,the steady state mathematical model of the circuit is established, this paper anylyzed the boost inductance,unbalanced load, voltage balance control constraints which affect the input power factor of the circuit. Based on the working circuit vector diagram, different control strategies to the traditional PFC rectifier circuit is obtained. And this paper demonstrated the validation of the proposed topology and control strategy, based on the simulation adopting corresponding control strategy. On this basis, this paper discussed the development of cascaded multi-level rectifier diode H-bridge level experiment platform, and on the experiment platform and experiment in this paper, the research content, experimental results evidenced the validity of the results.Then, the paper analyzed the deficiency of the proposed two cascaded H-bridge multi-level rectifier topologies. After that, the paper came out with a new kind of hybrid cascaded H-bridge topology. On the basis of introducing the working principle of the circuit, its steady-state dc m-del is set up, and it concluded the input power factor constraints, output dc voltage control constraint conditions, and load imbalance constraint conditions. After analyzing the normal working vector diagram of the circuit, based on the corresponding control strategy of the hybrid cascaded H-bridge, the simulation of the mixed cascade topology is put forward. After that, experiment platform to complete the basic working principle, and control strategy is followed. Simulation andexperimental results verified the validity and superiority of the proposed topology and control strategy. In addition, the hybrid cascaded H-bridge structure Matlab simulation and three-phase hybrid cascaded H-bridge experiment platform proved the correctness of the three-phase hybrid cascaded H-bridge circuit topology. In the end, this paper compared the existing cascade multi-level topologies, and compared the proposed three cascaded H-bridge type multi-level rectifier topologies.