不对称三相电压下电压源型换流器谐波分析与抑制策略

发布时间：2018-07-20 13:58

【摘要】：不对称三相电压下,电压源型换流器(VSC)将产生低次谐波,给电网造成谐波污染。随着VSC在电力系统中的广泛应用,这类问题必须得到更多的关注,提出有效的解决方法。基于动态相量和序分量,推导出序分量动态相量,并对其特性进行了分析;将含开关函数描述的VSC时域模型转化为动态相量模型;定义交流电流和直流电压的各阶序分量动态相量为状态变量,建立了以状态空间描述的VSC序分量动态相量谐波分析模型,综合考虑了开关函数的详细动态特性和交直流侧谐波的相互作用,从而揭示了VSC产生谐波的机理,实现了VSC谐波的解析求解。在此基础上,提出负序补偿的不对称调制策略,以抑制低次谐波的产生。通过各种不对称情况下的仿真和计算,验证了所提出的谐波分析模型的正确性和谐波抑制策略的有效性。
[Abstract]:The voltage source converter (VSC) will produce low order harmonics under asymmetrical three phase voltage, which will cause harmonic pollution to the power network. With the wide application of VSC in power system, more attention must be paid to these problems and effective solutions are proposed. Based on the dynamic phasor and sequence component, the dynamic phasor of ordered component is derived and its characteristics are analyzed, and the VSC time-domain model with switching function is transformed into dynamic phasor model. The dynamic phasor of each order component of AC current and DC voltage is defined as state variable, and the dynamic phasor harmonic analysis model of VSC sequence component described by state space is established. The detailed dynamic characteristics of the switching function and the interaction of AC / DC side harmonics are considered synthetically. The mechanism of harmonic generation in VSC is revealed and the analytical solution of VSC harmonics is realized. On this basis, an asymmetric modulation strategy of negative sequence compensation is proposed to suppress the generation of low order harmonics. The correctness of the proposed harmonic analysis model and the effectiveness of the harmonic suppression strategy are verified by simulation and calculation under various asymmetrical conditions.
【作者单位】：华南理工大学电力学院;
【基金】：国家自然科学基金资助项目(51307061)~~
【分类号】：TM46

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