高压直流(high voltage direct current,HVDC)输电线路行波保护及测距装置的分析、整定主要依赖于数值仿真方法,难以反映行波过程的物理本质和影响因素,也无法进行整定计算。分析了直流线路行波在故障点及包含直流滤波器的线路末端的折...高压直流(high voltage direct current,HVDC)输电线路行波保护及测距装置的分析、整定主要依赖于数值仿真方法,难以反映行波过程的物理本质和影响因素,也无法进行整定计算。分析了直流线路行波在故障点及包含直流滤波器的线路末端的折反射规律,在此基础上推导了基于无畸变传输线模型的行波解析解,用以研究直流滤波器、故障电阻和故障位置对直流线路行波的影响。研究表明:直流滤波器使行波波头由阶跃波变成衰减的振荡波,从而使其变化率和幅值都减小;过渡电阻主要影响行波波头的幅值大小。基于该解析表达式计算而得的行波变化率可用于实际工程中的行波保护整定。在EMTDC仿真软件中,结合中国某实际直流系统建立仿真模型,大量的仿真结果验证了所得出的解析解以及分析结果的正确性和有效性。展开更多
An analytical solution for scattering of plane P waves by circular-arc layered alluvial valleys was derived by Fourier-Bessel series expansion technique, and the solution was utilized to analyze the effects of alluvia...An analytical solution for scattering of plane P waves by circular-arc layered alluvial valleys was derived by Fourier-Bessel series expansion technique, and the solution was utilized to analyze the effects of alluvial sequence and their relative stiffness on the scattering of incident waves.展开更多
文摘高压直流(high voltage direct current,HVDC)输电线路行波保护及测距装置的分析、整定主要依赖于数值仿真方法,难以反映行波过程的物理本质和影响因素,也无法进行整定计算。分析了直流线路行波在故障点及包含直流滤波器的线路末端的折反射规律,在此基础上推导了基于无畸变传输线模型的行波解析解,用以研究直流滤波器、故障电阻和故障位置对直流线路行波的影响。研究表明:直流滤波器使行波波头由阶跃波变成衰减的振荡波,从而使其变化率和幅值都减小;过渡电阻主要影响行波波头的幅值大小。基于该解析表达式计算而得的行波变化率可用于实际工程中的行波保护整定。在EMTDC仿真软件中,结合中国某实际直流系统建立仿真模型,大量的仿真结果验证了所得出的解析解以及分析结果的正确性和有效性。
基金State Natural Science Foundation of China (No.59878032).
文摘An analytical solution for scattering of plane P waves by circular-arc layered alluvial valleys was derived by Fourier-Bessel series expansion technique, and the solution was utilized to analyze the effects of alluvial sequence and their relative stiffness on the scattering of incident waves.
