特高压半波长线路输电能力与暂态稳定影响因素

Power Transmission Capability and Transient Stability Influence Factors of UHV Half-Wavelength Transmission Line

近年来,在构建全球能源互联网的趋势下半波长输电技术再次得到关注。为研究特高压半波长输电系统的输电能力,搭建1000k V半波长输电系统模型,计算特高压半波长输电系统自然功率,给出输电能力研究的边界条件,分析半波长输电系统最严重故障点在不同开机方式下的漂移现象,从暂态稳定极限角度研究发电机参数、励磁系统模型、开机方式、继电保护动作时序、电压水平、受端短路容量和变压器短路电抗等因素对半波长输电系统输电能力的影响,并定量给出输电能力的影响范围。研究结果表明,输送距离3000km的1000k V半波长输电系统具有输送自然功率及以上功率的输电能力,除变压器短路电抗以外,其他因素对输电能力均有较大的影响。

Recently, under trend of building global energy interconnection（GEI）, half-wavelength transmission technology is concerned again. In order to study transmission capacity of UHV half-wavelength transmission system, a model of half-wavelength UHV transmission system is constructed in this paper and its natural power is calculated. Boundary conditions for calculating power transmission capability are presented. Drift phenomenon of serious fault locations in different generating schemes is analyzed. From perspective of transient stability limit, influencing factors such as generator parameters, excitation system model, generating scheme, operation sequence of protective relays, voltage level, short-circuit capacity of receiving system, and short-circuit reactance of transformers, are examined. Influence range of the transmission capability is presented quantitatively. Research results show that 1000 k V half-wavelength power transmission system possesses transmission capability of natural power and above for 3000 km transmission distance. Except transformer short circuit reactance, these factors have remarkable impact on transmission capability.