参考波为梯形波的模块化多电平变流器模块电容电压均压策略

发布时间：2018-06-26 04:52

本文选题：模块化多电平变流器 + 梯形波　；参考：《高电压技术》2017年01期

【摘要】：模块化多电平变流器(MMC)在高压大功率直流领域得到了广泛的认可和应用,同时高频化能够减小设备的重量和体积,对MMC变流器桥臂参考电压为中高频梯形波时的模块电容电压均压策略进行分析。首先分析了梯形参考波的选取和应用场合。其次,针对梯形波提出一种模块电容电压均压策略:在桥臂电压上升和下降阶段采取预先排序的方式,减少了一个基波周期内的开通关断次数,同时降低了控制硬件的要求。另外,针对桥臂之间模块电压不均衡的情况,对桥臂参考电压平顶期进行修正,在上下桥臂之间建立通信,根据上下桥臂模块电容电压平均值的大小决定桥臂参考电压平顶期的实际导通个数。此外,根据梯形波和变换器的特点,分析了抑制谐波的策略。最后在PSIM中对所提出的方法进行建模仿真,结果表明:桥臂之间和桥臂内部的模块电容电压实现了均压,与传统的正弦波的调制方法相比,开关频率大大减小,且回路中3次谐波和5次谐波电流分量几乎为0。
[Abstract]:Modular multilevel converters (MMC) have been widely recognized and applied in the field of high voltage and high power DC. At the same time, high frequency can reduce the weight and volume of equipment. The voltage equalizing strategy of the module capacitor voltage is analyzed when the reference voltage of the bridge arm of MMC converter is medium and high frequency trapezoidal wave. Firstly, the selection and application of trapezoidal reference wave are analyzed. Secondly, a voltage equalizing strategy of module capacitor voltage is proposed for trapezoidal wave. In the stage of rising and falling of bridge arm voltage, the method of pre-ranking is adopted, which reduces the turn-off times in a fundamental wave cycle and reduces the requirement of control hardware at the same time. In addition, the reference voltage flattening period of the bridge arm is corrected to establish the communication between the upper and lower arms. According to the average capacitance voltage of the upper and lower arm modules, the actual number of the bridge arm reference voltage flattening period is determined. In addition, according to the characteristics of trapezoidal wave and converter, the harmonic suppression strategy is analyzed. Finally, the proposed method is modeled and simulated in PSIM. The results show that the module capacitance voltage between and inside the bridge arm achieves voltage equalization, and compared with the traditional sine wave modulation method, the switching frequency is greatly reduced. The third and fifth harmonic current components in the loop are almost zero.
【作者单位】：中国科学院电工研究所大功率电力电子与直线驱动技术研究部;中国科学院大学;国网北京市电力公司;
【基金】：国家电网公司总部科技项目(52020116000D)~~
【分类号】：TM46

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