应用于风力发电的MMC子模块新型电容降容控制

发布时间：2018-06-16 20:41

本文选题：模块化多电平换流器 + 低频大电流工况　；参考：《电力系统自动化》2017年09期

【摘要】：模块化多电平换流器(MMC)因其多方面优势适用于中压及更高电压等级的风力发电,但由于风电机组的低频大电流工况,机侧MMC子模块电容电压波动大,需要大的直流滤波电容。提出一种在负序二倍频环流控制器中注入环流来抑制子模块电容电压波动的策略,指出了所注入的环流的初相角的选择依据,并给出了基于该方法的子模块电容容值选取依据。针对该策略带来的环流二倍频分量增加的问题,提出了一组表征子模块电容电压抑制效果相对于环流增加量的折中系数,指出需根据系统要求来选择不同的折中系数作为评价标准,以达到所需求的总体性能。基于MATLAB/Simulink的仿真结果验证了理论分析的正确性和所提控制策略的有效性。
[Abstract]:Modular multilevel converter (MMC) is suitable for wind power generation with medium voltage and higher voltage because of its advantages in many aspects. However, because of the low frequency and high current condition of wind turbine, the capacitance voltage of MMC submodule on the side of MMC fluctuates greatly, which requires large DC filter capacitance. A strategy of injecting circulation into negative sequence second harmonic loop controller to suppress voltage fluctuation of submodule capacitance is proposed. The selection basis of initial phase angle of injected circulation is pointed out, and the basis of selecting capacitance value of submodule based on this method is given. In order to solve the problem of increasing the frequency doubling component of the circulation, a set of eclectic coefficients representing the capacitor voltage suppression effect of the submodule relative to the increase of the circulation are proposed. It is pointed out that different eclectic coefficients should be selected as the evaluation criteria according to the system requirements to achieve the required overall performance. The simulation results based on MATLAB / Simulink verify the correctness of the theoretical analysis and the effectiveness of the proposed control strategy.
【作者单位】：浙江大学电气工程学院;
【基金】：国家自然科学基金资助项目(51177147)~~
【分类号】：TM614

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