半波长级与全波长级输电系统的过电压与同步稳定性分析

Overvoltage and Synchronization Stability Analysis of Half-Wavelength Order and Full-Wavelength Order Transmission Systems

文章建立了半波长级与全波长级输电系统稳态特性与暂态特性分析的一般性电路模型,推导出了远距离输电系统的无损线数学模型和有损线数学模型。采用解析分析与数值计算相结合的方法,分析了输电距离在全波长级范围变化时的送受端状态量特性及沿线电压分布。利用小信号分析法对远距离输电系统的同步稳定性进行了分析,得出了能保持同步稳定性的输电距离范围。根据同步稳定性与频率偏差约束条件,确定了半波长级与全波长级输电系统的可行输电距离。利用解析分析方法研究了远距离输电系统的暂态工频过电压特性和暂态稳定特性,推导出了严重故障点位置计算公式和最大过电压计算公式,并基于等面积法对系统的暂态稳定性进行了分析。

A general circuit model for analyzing the steady and transient characteristics of half-wavelength order and fullwavelength order transmission systems is established,and the lossless and lossy line mathematical models of long-distance transmission systems are derived. The characteristics of the state variables at the sending and receiving ends as well as the distribution of the voltage along the transmission line when the transmission distance varies in the full wavelength range are analyzed by combining the theoretical analysis and numerical calculation. The synchronization stability of long-distance transmission systems is analyzed by using small signal analysis method,and the transmission distance range which can keep synchronization stability is obtained. The feasible transmission distance of the half-wavelength order and the full-wavelength order transmission system is determined according to the constraints of synchronization stability and frequency deviation. The transient power frequency overvoltage and the transient synchronization stability of long-distance transmission systems are studied by analytical method. The calculation formula for the location of the most serious fault point and the calculation formula for the maximum overvoltage are derived; and the transient synchronization stability of the system is analyzed based on the equal area method.