STATCOM对高压直流输电系统运行特性的影响研究

发布时间：2018-04-24 21:14

本文选题：高压直流输电 + 静止同步补偿器　；参考：《华北电力大学》2014年硕士论文

【摘要】：传统高压直流输电(High Voltage Direct Current, HVDC)以其技术上和经济上的独特优势得到了广泛的应用。随着直流输电工程在我国逐渐增多,如何克服HVDC的不足,减少其换相失败发生的概率,已成为工程中越来越关注的问题。将静止同步补偿器(Static Synchronous Compensator, STATCOM)并联接入HVDC系统逆变侧交流母线,可以有效调节交流母线电压,等效增强受端系统强度,从而提高系统的稳定性。首先对HVDC和STATCOM的拓扑结构、数学模型和控制策略进行了研究,并在PSCAD/EMTDC环境中搭建了含有STATCOM的单馈入和双馈入HVDC系统模型；研究了不含STATCOM时双馈入HVDC系统受端交流母线电压间的相互作用,考虑STATCOM接入双馈入HVDC系统后,分析了STATCOM对HVDC受端交流母线电压的影响,并研究了含有STATCOM的HVDC系统的故障恢复特性。以临界短路比作为评价指标,研究了不同容量STATCOM对单馈入HVDC系统和双馈入HVDC系统运行极限的影响。最后提出了一种含有STATCOM的HVDC系统的改进控制策略,即STATCOM的定交流电压控制配备了交流电压参考值调节控制,HVDC整流侧的定直流电流控制和逆变侧的定关断角控制分别配备了附加直流电流和附加关断角控制。研究结果表明,STATCOM接入HVDC逆变侧交流母线,可以有效改善HVDC系统的运行特性并提高系统的稳定性,所提出的改进控制策略可以有效降低换相失败发生的概率。
[Abstract]:High Voltage Direct current (HVDC) has been widely used in traditional HVDC because of its unique technical and economic advantages. With the increasing number of HVDC transmission projects in China, how to overcome the shortage of HVDC and reduce the probability of commutation failure has become a more and more important problem in the engineering. The static Synchronous compensator (STATCOM) is connected in parallel to the AC bus of the inverter side of the HVDC system. The voltage of the AC bus can be adjusted effectively and the strength of the receiver system can be enhanced effectively, thus the stability of the system can be improved. Firstly, the topology, mathematical model and control strategy of HVDC and STATCOM are studied, and the single and double fed HVDC system models with STATCOM are built in the PSCAD/EMTDC environment. In this paper, the interaction between AC bus voltages at the receiving end of a double-fed HVDC system without STATCOM is studied. The influence of STATCOM on the AC bus voltage at the receiving end of the HVDC system is analyzed after the STATCOM is connected to the double-fed HVDC system. The fault recovery characteristics of HVDC system with STATCOM are studied. The critical short-circuit ratio is used as the evaluation index to study the effect of different capacity STATCOM on the operation limit of single-feed HVDC system and double-fed HVDC system. Finally, an improved control strategy for HVDC system with STATCOM is proposed. That is to say, the constant AC voltage control of STATCOM is equipped with AC voltage reference control. The constant DC current control on the rectifier side and the fixed turn-off angle control on the inverter side are equipped with the additional DC current control and the additional turn-off angle control respectively. The results show that the AC bus of HVDC inverter can effectively improve the performance of HVDC system and improve the stability of the system. The proposed improved control strategy can effectively reduce the probability of commutation failure.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM721.1

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