The optical chaotic communication system using open-loop fiber transmission is studied under strong injection conditions. The optical chaotic communication system with open-loop configuration is studied using fiber tr...The optical chaotic communication system using open-loop fiber transmission is studied under strong injection conditions. The optical chaotic communication system with open-loop configuration is studied using fiber transmission under strong injection conditions. The performances of fiber links composed of two types of fiber segments in different dispersion compensation maps are compared by testing the quality of the recovered message with different bit rates and encrypted by chaotic modulation （CM） or chaotic shift keying （CSK）. The result indicates that the performance of the pre-compensation map is always worst. Two types of symmetrical maps are identical whatever the encryption method and bit-rate of message are. For the transmitting and the recovering of message of lower bit rate （1 Gb/s）, the post-compensation map is the best scheme. However, for the message of higher bit rate （2.5 Gb/s）, the parameters in communication system need to be modified properly in order to adapt to the high-speed application. Meanwhile, two types of symmetrical maps are the best scheme. In addition, the CM method is superior to the CSK method for high-speed applications. It is in accordance with the result in a back-to-back configuration system.展开更多
针对高压直流输电系统(high voltage direct current,HVDC)引起的电力系统次同步振荡问题,该文建立了多输入多输出闭环互联系统模型,将系统拆分为HVDC子系统和交流子系统。当2个子系统的开环模式接近时,系统发生了近似强模式谐振,弱化...针对高压直流输电系统(high voltage direct current,HVDC)引起的电力系统次同步振荡问题,该文建立了多输入多输出闭环互联系统模型,将系统拆分为HVDC子系统和交流子系统。当2个子系统的开环模式接近时,系统发生了近似强模式谐振,弱化对应闭环模式的阻尼水平从而引发系统的次同步振荡。在此基础上,为了评估近似强模式谐振情况下系统的稳定性,提出一种开环模式分析方法,可根据开环模式信息对闭环模式分布位置进行预估,进而判断系统是否会发生次同步振荡。最后,通过对示例系统的仿真分析验证了开环模式分析方法的有效性,同时分析了系统运行点和控制环节参数对于近似强模式谐振的影响。展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 60872123)the Joint Fund of the National Natural Science Foundation and the Guangdong Provincial Natural Science Foundation, China (Grant No. U0835001)the Guangdong Provincial Natural Science Foundation (Grant No. S2011010002144)
文摘The optical chaotic communication system using open-loop fiber transmission is studied under strong injection conditions. The optical chaotic communication system with open-loop configuration is studied using fiber transmission under strong injection conditions. The performances of fiber links composed of two types of fiber segments in different dispersion compensation maps are compared by testing the quality of the recovered message with different bit rates and encrypted by chaotic modulation （CM） or chaotic shift keying （CSK）. The result indicates that the performance of the pre-compensation map is always worst. Two types of symmetrical maps are identical whatever the encryption method and bit-rate of message are. For the transmitting and the recovering of message of lower bit rate （1 Gb/s）, the post-compensation map is the best scheme. However, for the message of higher bit rate （2.5 Gb/s）, the parameters in communication system need to be modified properly in order to adapt to the high-speed application. Meanwhile, two types of symmetrical maps are the best scheme. In addition, the CM method is superior to the CSK method for high-speed applications. It is in accordance with the result in a back-to-back configuration system.
文摘针对高压直流输电系统(high voltage direct current,HVDC)引起的电力系统次同步振荡问题,该文建立了多输入多输出闭环互联系统模型,将系统拆分为HVDC子系统和交流子系统。当2个子系统的开环模式接近时,系统发生了近似强模式谐振,弱化对应闭环模式的阻尼水平从而引发系统的次同步振荡。在此基础上,为了评估近似强模式谐振情况下系统的稳定性,提出一种开环模式分析方法,可根据开环模式信息对闭环模式分布位置进行预估,进而判断系统是否会发生次同步振荡。最后,通过对示例系统的仿真分析验证了开环模式分析方法的有效性,同时分析了系统运行点和控制环节参数对于近似强模式谐振的影响。
