基于非特征谐波潮流统一算法的±800kV特高压直流输电系统非特征谐波分析

Non-characteristic harmonic analysis of±800 kV UHV DC transmission system based on unified non-characteristic harmonic load flow algorithm

对±800 kV特高压直流输电系统的非特征谐波进行分析可以为特高压换流站交直流侧的滤波器优化设计提供依据,为治理谐波提高电能质量提供参考。交直流系统非特征谐波潮流统一算法建立了换流装置的数学模型,同时考虑3种不对称因素,并计及Y/△接线方式换流变压器绕组中零序环流的影响。该方法以统一基波和特征谐波潮流计算结果为基础,以特征谐波潮流计算所得出的谐波电压和电流作为非特征谐波计算的迭代初值。列出相应的换流器数学模型及全系统的方程式,用高斯-塞德尔法迭代法进行求解。采用该算法对某±800 kV特高压直流输电系统的非特征谐波进行了分析和计算。

The non-characteristic harmonic analysis of 4-800 kV UHVDC（Uhra High Voltage Direct Current） transmission system provides reference for the optimal design of filters at AC and DC sides of converter station and for the harmonic mitigation and electricity quality improvement. The mathematic model of converter is built by the unified non-characteristic harmonic load flow algorithm, which considers three asymmetry factors and the zero sequence current flowing through the transformer groups of Y/△ connection. The calculated results of the unified fundamental and characteristic harmonic load flow algorithm are adopted as the initial values of the unified non-characteristic harmonic load flow algorithm. The corresponding mathematic model of the converters together with the whole system equation are set up and solved with the Gauss-Seidel iteration algorithm. The non-characteristic harmonics of a ± 800 kV UHVDC transmission system are analyzed and calculated with the proposed unified non-characteristic harmonic load flow algorithm.