不平衡交流电网模块化多电平变流器特性分析及环流抑制方法

发布时间：2019-05-12 14:06

【摘要】：高压直流输电系统中的模块化多电平变流器的安全稳定运行是当前的研究热点。当交流侧出现不平衡时,通常需要对环流及直流侧脉动分别进行控制。因此,针对不平衡交流电网的情况,首先利用桥臂瞬时功率方程分析直流侧波动状态;其次,再通过不平衡下的调制函数及子模块端口电压方程,推导出整个桥臂模块电压波动表达式及环流表达式。分析得到正、负、零序2倍频波动分量贯穿桥臂,以此提出一种无需正负序分离和坐标变换的分相控制的环流抑制策略,以同时消除桥臂环流及直流电流的脉动。最终,通过傅里叶分析对不平衡下的系统特性进行了验证,并利用Matlab及实验平台对所提出的控制策略进行了仿真和实验验证。
[Abstract]:The safe and stable operation of modular multilevel converters in HVDC system is a hot research topic at present. When there is imbalance on the AC side, it is usually necessary to control the circulation and the pulsation on the DC side respectively. Therefore, according to the situation of unbalanced AC power grid, the instantaneous power equation of bridge arm is used to analyze the fluctuation state of DC side. Secondly, through the unbalanced modulation function and the voltage equation of the submodule port, the voltage fluctuation expression and circulation expression of the whole bridge arm module are derived. In order to eliminate the pulsation of the current and DC current at the same time, the positive, negative and zero-sequence 2-fold frequency fluctuation components are obtained through the bridge arm, and a phase-separated control strategy without positive and negative sequence separation and coordinate transformation is proposed in order to eliminate the pulsation of the bridge arm circulation and DC current at the same time. Finally, the characteristics of the system under imbalance are verified by Fourier analysis, and the proposed control strategy is simulated and verified by Matlab and experimental platform.
【作者单位】：北京交通大学国家能源主动配电网技术研发中心;北京电动车辆协同创新中心;
【基金】：北京市科技计划项目(Z161100000716003)~~
【分类号】：TM46;TM721.1

【相似文献】