多馈入直流系统的VSC-HVDC落点优选方法

Optimal Position of VSC-HVDC Access to Multi-infeed HVDC System

针对多馈入系统的新增直流落点优选问题,首先对采用的基于VSC-HVDC的结构和特点进行介绍,并列举VSC-HVDC较LCC-HVDC的优势,然后在分析研究直流落点优选的必要性基础上,全面考虑了新增直流对交直流系统稳定性的影响后,建立了多馈入短路比、直流换相失败风险以及受端系统失稳风险为指标评价体系,在对各项指标进行规范化处理后,根据线性加权法得出的综合指标,从备选方案中选择最优落点;最后将所提直流落点优选方法应用于实际算例,得出新增直流的最佳接入位置,提高了受端系统的安全稳定性。

To solve the problem of the optimal position of new HVDC access to multi-infeed HVDC system, first the paper introduces the structure and characteristics of voltage source converter based high voltage direct current （VSC-HVDC） , and expounds the advantages of VSC-HVDC over line commutated converter based high voltage direct current （LCC-HVDC）. Then on the basis of analyzing the necessity of research on the optimal position of VSC-HVDC and fully considering the impact of the new HVDC on the stability of AC-DC system, the paper establishes a index evaluation system composed of muhi-infeed short circuit ratio （MISCR） , HVDC commutation failure risk and receiver system instability risk, and gets a composite indicator by adding indicators linearly according their weights after standardizing the indicators. Based on which the optimal position is selected from alternatives based on the composite metrics. Finally, the proposed method is applied to the practical example to obtain the optimal position of the new HVDC, and improving the safety and stability of the receiver system.