摘要
为解决基于链式H桥的SVG在三相电网电压不平衡时的直流侧均压控制的问题,在分析了链式H桥SVG的功率模型中出现直流侧电压不均衡原因的基础上,提出了采用三层控制结构对基于链式H桥的SVG星型接法直流侧电压进行分层稳压、均压控制。首先对总有功进行控制,采用正序和负序解耦的控制方法;其次是在三相交流电压相间不平衡时采用零序电压注入法进行均压控制;最后对三相中每一个单相内各个模块间采用有功、无功电流注入法以实现模块间均压。实验结果表明,接入电网在三相电压出现一定程度的不平衡时,运用三层分级控制策略能使链式H桥SVG星型接法的直流侧电压能够保持相对稳定和均衡。
In order to solve the problem of DC side voltage control based on cascade H-bridge SVG under the condition of unbalanced three-phase power grid voltage, three-layer control structure is adopted to perform the layered stabilivolt and the control of voltage sharing on the DC side voltage of SVG star connection of cascade H-bridge based on the analysis of the imbalanced reason of DC side voltage occurred in the power model cascade H-bridge SVG. Firstly, the total active power is controlled by using of the positive sequence and negative sequence decoupling control method; Then, the injection method of zero sequence voltage is adopted to conduct the control of voltage sharing under the condition of the unbalanced three-phase AC voltage; Finally, aiming at various modules within every single phase of three phase, the active and reactive current injection methods are adopted to realize voltage sharing between modules. Experimental results show that access to power grid using three-layer hierarchical control strategy can make the DC side voltage of SVG star connection of cascade H-bridge relatively stable and balanced under the condition of unbalanced three-phase voltage.
出处
《辽宁工业大学学报（自然科学版）》
2017年第6期358-361,共4页
Journal of Liaoning University of Technology(Natural Science Edition)
作者简介
李丽萍（1966-），女（满族），辽宁凌海人，副教授。
