±660 kV银东直流输电系统逆变站换相失败分析

摘要

In this paper,we focus on the ±660 kV Yindong HVDC system and the detailed model of it is built using simulation tool PSCAD/EMTDC based on its real parameters.Equivalent model of Shandong power grid system at inverter side is also conducted using simulation software PSASP.Thus,the HVDC commutation failure and single-phase-to-ground fault at AC side are introduced.On this basis,the dynamic characteristics of Yindong HVDC system under single-phase-to-ground fault at Qingdao converter station are simulated and ana-lyzed.According to the results of mathematical derivation and simulation analysis,the various influencing fac-tors of Yindong HVDC system commutation failure are concluded,and a mitigation measures for commutation failure under this kind of fault that to emit the trigger pulse in advance and increase the advance firing angle is proposed.This study provides technical support for safe and stable operation of Yindong HVDC system.%以±660 kV银东直流输电系统为研究对象，根据其实际工程参数，利用PSCAD/EMTDC仿真工具，搭建直流输电系统模型。采用仿真软件PSASP对逆变侧山东电网进行等值建模。在介绍直流输电系统换相失败及交流输电系统单相接地的基础上，对青岛换流站发生单相接地故障时的银东直流输电系统的运行状况进行仿真分析。结合数学推导和仿真结果，分析了换向失败的机理和各种原因，提出了提前发触发脉冲和增大超前触发角来减少换相失败的措施，为直流输电系统的安全和稳定运行提供了技术支撑。