二极管中点箝位型三电平变流器改进设计

多电平变流器在风电并网的中高压大功率场合得到了广泛的研究和应用。以二极管中点箝位型三电平变流器为研究对象进行分析,其直流侧中点电位不平衡问题是该变流器的致命弱点,影响着变流器的可靠性。在此提出了一种解决三电平变流器中点电位平衡的硬件电路,与其他解决中点电位平衡的硬件电路相比,该电路不仅能使中点电位达到平衡,而且减少了电路中的器件,使电路的复杂程度降低,运行成本降低。最后用MATLAB/SIMULINK仿真软件对该方案进行了仿真分析,仿真结果表明中点电位达到了平衡,从而验证了该方案的正确性。

Design and Improved of Diode Neutral Point Clamped Three-level Converter

Multi-level converters in the mid and high-voltage wind power grid applications has been widely studied and applied.This papper based on the diode neutral point clamped three-level converter as the research object which is analysis,the neutral point potential imbalance in dc side is the fatal weakness of the converter,which affects the reliability of three-level converter.Here presenting a hardware circuit to solve the problem of neutral point potential balance in the three-level converter,compared to other solutions to the neutral point potential balancing hardware circuit,this circuit does not only make the neutral point potential balance, but also reduce the circuit device. Therfore it can reduce the circuit complexity, and operating costs. Finally, using MATLAB / SIMULINK simulation software for the simulation analysis of the program, it indicates that the neutral point potential to achieve balance, so the correctness of the program is verified.