联接含惯量交流系统的VSC-HVDC系统特性分析

发布时间：2018-01-12 19:45

本文关键词：联接含惯量交流系统的VSC-HVDC系统特性分析　出处：《高电压技术》2017年04期 　论文类型：期刊论文

【摘要】：目前针对电压源型高压直流输电(VSC-HVDC)系统控制特性的研究仅限于联接到等值交流系统的情形,建立VSC-HVDC系统联接到含惯量的交流系统的模型,研究弱系统条件下交流系统内部参数与VSC-HVDC系统的相互作用有重要意义。利用同步发电机(SG)模拟含惯量的交流系统,首先建立了连接到SG的VSC-HVDC系统的小信号模型,并验证了模型建立的正确性;利用参与因子法分析了特征根与状态变量的关联程度。采用特征根分析和仿真验证结合的方法,分别研究了线路阻抗、SG的惯性常数、阻尼系数的参数变化对系统特征根的影响规律;最后研究了VSC控制器参数对系统稳定性的影响作用。结果和结论证明,系统小信号稳定性随着系统线路阻抗角减小、短路比(SCR)的降低而降低;当惯性常数取值1.2 s时系统小信号稳定性先增强后减弱但不会失稳,当阻尼系数D在0~0.5范围内变化时,系统小信号稳定性先增强后减弱,VSC控制器参数对系统小信号稳定性影响也较大,在一定范围内调整SG惯性常数、阻尼系数和VSC控制器内外环参数值可以提高系统小信号稳定性。
[Abstract]:At present, the research on the control characteristics of VSC-HVDC (Voltage Source HVDC) system is limited to the case of connection to the equivalent AC system. The model of connecting VSC-HVDC system to AC system with inertia is established. It is important to study the interaction between the internal parameters of AC system and the VSC-HVDC system under weak system conditions. The synchronous generator is used to simulate the AC system with inertia. First, the small-signal model of VSC-HVDC system connected to SG is established, and the correctness of the model is verified. The correlation between the characteristic root and the state variables is analyzed by using the participation factor method, and the inertia constant of the line impedance and SG is studied by the method of characteristic root analysis and simulation verification. The influence of the parameter change of damping coefficient on the characteristic root of the system; Finally, the effect of VSC controller parameters on the stability of the system is studied. The results and conclusions show that the small signal stability of the system decreases with the decrease of the impedance angle and the short circuit ratio of the system. When the inertia constant is 1.2 s, the small signal stability of the system first increases and then weakens, and when the damping coefficient D changes within the range of 0 ~ 0.5, the small signal stability of the system increases first and then weakens. The parameters of VSC controller have great influence on the small signal stability of the system. Adjusting the SG inertia constant in a certain range, damping coefficient and the internal and external loop parameters of the VSC controller can improve the small signal stability of the system.
【作者单位】：华北电力大学新能源电力系统国家重点实验室;国网北京经济技术研究院;
【基金】：国家自然科学基金面上项目(51177042) 中央高校基本科研业务专项资金(2015XS08)~~
【分类号】：TM721.1
【正文快照】： 0引言1以全控型器件为基础的电压源型高压直流输电(VSC-HVDC)由于其能灵活控制系统有功和无功传输;动态补偿交流母线的无功功率,稳定交流母线电压;可向无源网络供电;不易发生换相失败等优点,已广泛应用于直流输电领域[1-2]。目前,随着用户侧用电需求的增加,系统传输有功功率量

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