【作者】 李鹏飞；

【导师】 卢文冰；

【作者基本信息】 华北电力大学（北京） ， 通信与信息系统， 2011， 硕士

【摘要】 双向工频通信系统(Two Way Automatic Communication System, TWACS)是一种基于电力配电网络的通信系统,其在上世纪九十年代出现于美国。TWACS系统通过在电压过零时刻在电压、电流波形上产生畸变来传递信息,其能够通过简单、经济的手段实现跨变压器台区的长距离传输,是一种非常适用于低速传输的信道传输模式。其具有成本低廉、传输距离远、抗干扰能力强、维护方便等优点。目前双向工频通信在国内的应用,主要是在个别变压器台区使用进行远程抄表等工作。由于应用范围很小,目前传统的主站设备主要部分是采用工控机配置A/D采集卡,上行解调方法为通过电流采样值累加和计算等方法。这种主站模式上行解调性能较差,存在速度慢,效率低、故障率高等缺点,难以适应于当变压器台区数量众多、多条线路同时有上行信号、电网结构复杂等情况,因此需要改进。针对这种现象,本文在分析了双向工频通信系统的通信原理和系统组成的基础上,研究并实现了基于分布式结构的工频通信主站设备。在分布式结构主站设备中,根据工频通信主站的基本功能,将主站设备分为管理单元、多个上行信号解调单元、下行信号调制单元。由管理单元通过通信协议来实现多线上行信号的并行接收、管理。主站设备中,管理单元由工控机和后台软件组成,只承担管理作用；上行解调单元由MCU、16位A/D转换器和电压、电流传感器等组成,通过MCU电路模块的高速计算,根据上行调制编码通过时域差分和互相关运算等算法进行各路上行解调,替代了传统的工控机集中解调；下行信号调制单元由可控硅控制电路组成,进行下行信号的调制发送。同时上行解调单元中的MCU高速计算也为多相上行信号的并行解调提供了硬件基础。根据本文方法研制的工频通信主站设备在油田电网现场进行了试验运行,运行结果表明,分布式结构主站能够适应环境恶劣、强噪声、多线路、多变压器台区的工业生产环境,这种新型主站设备能够准确接收多线路上行信号的并行传输,通信质量优良。目前该主站设备模式和设备已经在实际工程项目中得到了应用。更多还原

【Abstract】 TWACS(Two Way Automatic Communication System) is a kind of communication system based on the power distribution network, which appeared in the United States in the 1990s. TWACS transmits information through producing distortion on voltage and current waveform at the voltage zero-crossing moment. It can pass the transformer to realize long distance transmission by a simple and effective way, and is very suitable for low speed channel transmission mode. It has the advantages with low cost, long transmission distance, strong anti-jamming capability, convenient maintenance, etc.Currently TWACS in our country is mainly used for long-distance meter reading in individual transformer area, etc. Due to the application scope is very small, present main parts of traditional master station equipments are using Industrial Personal Computer for collocating A/D acquisition card. Inbound demodulation is through the accumulation and calculation for current sample value. The inbound demodulation performance of master station mode is poorer, and with the shortcoming of slow speed, low efficiency and high failure rate. So it is difficult to adapt to the situation when transformer is with large number, multiple lines at the same time having inbound signals and the power grid structure is complex, etc., so it needs to be improved.According to this phenomenon, the paper analyzes the TWACS principle and system composition, studies and realizes TWACS master station equipments based on distributed structure. For the distributed structure master station equipments according to the basic function of TWACS master station, the master station equipments will be divided into management unit, multiple inbound signal demodulation unit, outbound signal modulation unit. Management unit will be through the communication protocol to achieve parallel receiving and management of multiple line inbound signal. In the master station, management unit is composed of Information Processing Center and backend software. Inbound demodulation unit consists of MCU,16 A/D converter and voltage, current sensor etc.. Supercomputing of MCU circuit module, inbound demodulation according to the inbound modulation and coding and by time-domain difference and cross-correlation algorithm etc., which has replaced traditional Industrial Personal Computer concentrated demodulation. Outbound signal modulation unit composed by silicon-controlled rectifier control circuit for the modulation and sending of outbound signal. MCU circuitry of the inbound demodulation unit calculates quickly, which provides hardware base for parallel demodulation of multiphase inbound signal.TWACS master station equipments designed according to this method is tested in oilfield network, the operation results show that the distributed structure master station can adapt to the industrial production rugged environment with strong noise, multiple lines and more transformer. The new master station equipments can correctly received concurrent transmission of multiple lines inbound signal, and with high the communication quality. At present, the master station equipments mode and equipments have been used in practical project.更多还原