考虑电压动态过程的含电网换相换流器的高压直流输电小信号建模方法

对含电网换相换流器的高压直流输电（line commutated converter high voltage direct current，LCC-HVDC）系统进行小信号稳定性分析时，存在小信号模型精度低、分析结果无法为系统稳定运行提供参考的问题。因此，提出一种计及电压动态过程的小信号建模方法。对LCC-HVDC状态空间模型进行改进，修正了逆变侧换流站内部的角度关系与换相角表达式，在模型中引入考虑电压动态过程的状态方程，并基于此模型计算系统运行的控制参数稳定域。通过PSCAD电磁暂态仿真软件对模型进行验证，并与传统小信号模型作对比，结果表明建立的考虑电压动态过程的小信号模型精度高，小信号稳定性分析结果更准确。

LCC-HVDC Small Signal Modeling Method Considering Voltage Variation

In the analysis on small signal stability of line commutated converter high voltage direct current (abbr. LCC-HVDC) power transmission system, there were such shortages as low accuracy of small signal model and the analysis result could not provide reference for stable operation of power transmission. For this reason, a small signal modeling method, which took dynamic process of voltage into account, was proposed to improve the state-space model of LCC-HVDC system and to revise the angle relationship inside the inverted side converter station as well as the expression of trigger angle. A new state equation considering the dynamic process of voltage was led in the model, and based on this model the stability domain of control parameters for system operation was calculated. The proposed model was verified by PSCAD electromagnetic transient simulation and the obtained results were compared with that by traditional small signal model. Comparison results show that established small signal model possesses higher precision and the analysis results for small signal stability by the proposed model are of higher precision.