基于波参数的直流线路谐波阻抗解析方法  

A Novel Analytic Method of DC Line Harmonic Impedance Based on Wave Parameters

作　　者：刘心旸[1] 李亚男[1] 蒋维勇[1] 

机构地区：[1]国网北京经济技术研究院,北京市昌平区102209

出　　处：《电网技术》2015年第10期2842-2847,共6页Power System Technology

摘　　要：为深入研究直流线路的谐振特性,提出一种长线路模型的解析方法,并依托某在运±800 k V特高压直流输电工程进行了理论计算与仿真分析的对比研究。首先,推导出线路单位长度等效参数,并引入波参数对直流线路四端口网络进行求解,计算出各频率点的等值阻抗;其次,通过将EMTDC程序中的相域频变线路模型与计算结果进行对比分析,验证了仿真模型与所提解析方法的正确性与精度;最后,对直流系统200 Hz频段以内进行阻抗解析,并仿真分析了直流线路在各类典型故障下的过电压与过电流。结果表明:系统在50 Hz与100 Hz附近存在谐振风险,需要采取一定的谐振抑制措施。To study resonance characteristics of DC transmission line, a novel analytical method of DC line harmonic impedance is proposed, and full-scale comparison is carried out between theoretical calculation and EMTDC simulation results, based on certain UHVDC projects in operation. Firstly, per-unit-length R/L/C parameters are derived, wave parameters are referred to solve the simplified 4-port circuit of DC line, and DC equivalent impedance of each frequency is obtained with direct calculation. By comparison with scan result of phase domain frequency dependent model in EMTDC, both the method and model are demonstrated mutually. Furthermore, the integral characteristics of DC system impedance in range within 200 Hz is studied, simulation is performed to analyze the overvoltage and overcurrent conditions on transmission line according to all typical DC faults. Results indicate that there＇s risk of resonance at 50/100Hz, resonance suppression measures are necessary.

关 键 词：特高压直流输电 谐波阻抗 波参数 谐振特性 过电压 过电流 

分 类 号：TM72[电气工程—电力系统及自动化]