锡泰直流工程分层接入500/1000 kV交流电网仿真计算与现场系统试验结果分析

Analysis of Simulation Calculation and On-site System Test Results for Xitai UHVDC Project With Hierarchical Connection to 500 kV/1000 kV AC Grid

锡盟—泰州（简称锡泰）受端分层接入500 kV/1000 kV不同电压等级交流电网的特高压直流接线方式在世界上属于首创,其控制保护没有可借鉴的经验。为准确分析分层接入方式下特高压直流输电控制系统稳态运行与暂态过程的真实响应,分析了分层接入方式下特高压直流控制系统的分层结构和功能配置方案,对控制系统的关键环节,如分接头控制、阀组间电压平衡控制、无功功率控制和换相失败预测控制策略进行了计算分析,并与工程现场系统调试结果进行了对比,验证了仿真结果与现场系统调试的一致性。仿真模型可为分层接入方式特高压直流输电工程的特性研究提供技术支撑。

1： Ximeng-to-Taizhou（abbr. Xitai） ultra high voltage direct current（UHVDC） project with hierarchical connection to 500 kV/1000 kV AC system is the first of its kind created by China in the world, and there is no existing experience for this kind of DC control and protection system. To analyze true responses of control and protection system during steady-state operation and transient process of UHVDC transmission project accurately, an electromagnetic transient model of the actual control system is built on PSCAD/EMTDC platform. The structure and function scheme of UHVDC with hierarchical connection are analyzed. Key aspects of the control system, such as voltage balance between HV（High Voltage） and LV（Low Voltage） converters, transformer tap-changer control, reactive power control and improved commutation failure prediction control strategy, are analyzed and modeled. Through a lot of simulation tests for the built model and comparison with waveforms of test results of Xitai project, consistency between simulation results and dynamic response of actual control system is verified. The model can also offer technical support for characteristic research of other UHVDC transmission projects with hierarchical connection mode.