Cab signaling apparatus is the critical equipment for ground-vehicle communication in electrified railways.With the rapid development of high-speed and heavy-haul railways,the immunity to unbalanced traction current i...Cab signaling apparatus is the critical equipment for ground-vehicle communication in electrified railways.With the rapid development of high-speed and heavy-haul railways,the immunity to unbalanced traction current interference for cab signaling apparatus in the onboard train control system is increasingly demanded.This paper analyzes the interference coupling mechanism of the ZPW-2000 track circuit.Based on electromagnetic field theory and the actual working parameters,a calculation model is established to complete the quantitative research of the cab signal induction process and traction current interference.Then,a finite element model is built to simulate the process.The simulation results under the signal frequency,fundamental and harmonic interference are all consistent with the theoretical calculation results.The practical measurement data verify the coupling relationship between cab signal inductive voltage and rail current.Finally,an indirect immunity test method applying this relation for the cab signals is proposed,and the voltage indexes of the disturbance sources are determined,i.e.,the test limits.The results provide an accurate quantitative basis for the cab signaling research and design of the immunity test platform;besides,the proposed indirect test method can simplify the test configuration and improve test efficiency.展开更多
为提高移频轨道电路发码装置输出信号的质量及装置的可靠性,设计一种基于直接数字频率合成器(DDS,Direct Digital Synthesizer)芯片的发码装置。该装置由单片机直接控制DDS芯片产生移频信号,经过后级电路放大滤波后,输出到测试环线上,...为提高移频轨道电路发码装置输出信号的质量及装置的可靠性,设计一种基于直接数字频率合成器(DDS,Direct Digital Synthesizer)芯片的发码装置。该装置由单片机直接控制DDS芯片产生移频信号,经过后级电路放大滤波后,输出到测试环线上,供车载天线接收;单片机提供RS-485通信电路用来接收上位机的控制数据、有机发光二极管(OLED,Organic Light-Emitting Diode)显示屏和按键,作为便携式设备的人员操作接口。通过测试验证,该装置可精确输出ZPW-2000和FTGS这2种移频轨道电路的移频键控(FSK,Frequency-Shift Keying)调制信号,提高了输出信号的分辨率和精度,从而减小相邻轨道区段间的干扰,便于机车信号设备的解调。与既有的移频轨道电路发码装置相比,该装置具有信号质量高、结构简单、可靠性高、方便操作的优点。展开更多
基金This work was supported in part by the China Railway(Grant No.17CR062)Shenzhen Changlong Railway Electronic Engineering Co.,Ltd.(Project Name:Anti-interference Design and Verification Improvement of Cab Signaling Onboard System Apparatus).
文摘Cab signaling apparatus is the critical equipment for ground-vehicle communication in electrified railways.With the rapid development of high-speed and heavy-haul railways,the immunity to unbalanced traction current interference for cab signaling apparatus in the onboard train control system is increasingly demanded.This paper analyzes the interference coupling mechanism of the ZPW-2000 track circuit.Based on electromagnetic field theory and the actual working parameters,a calculation model is established to complete the quantitative research of the cab signal induction process and traction current interference.Then,a finite element model is built to simulate the process.The simulation results under the signal frequency,fundamental and harmonic interference are all consistent with the theoretical calculation results.The practical measurement data verify the coupling relationship between cab signal inductive voltage and rail current.Finally,an indirect immunity test method applying this relation for the cab signals is proposed,and the voltage indexes of the disturbance sources are determined,i.e.,the test limits.The results provide an accurate quantitative basis for the cab signaling research and design of the immunity test platform;besides,the proposed indirect test method can simplify the test configuration and improve test efficiency.
文摘与野生型油菜相比 ,叶绿素缺乏油菜突变体 Cr35 2 9L HC 多肽组成并未发生改变 ,但其含量却都明显降低 .RNA印迹及点杂交结果都显示出 Cr35 2 9cab基因的转录增加 .这些结果表明 :该叶绿素缺乏突变体仅影响L HC 多肽的蛋白含量 ;并未影响其组成 ;突变体 L HC 蛋白量的减少并非 cab基因转录降低所致 .可见转录水平的调节仅对 L HC 在类囊体膜上的积累起有限作用 ;
