基于宽频电磁法的接地网络探测仪样机研制

发布时间：2018-06-02 19:46

本文选题：宽频电磁法 + DSP　；参考：《吉林大学》2017年硕士论文

【摘要】：变电站运行过程中需要接地网的保护,接地网可以保护变电站内工作人员以及各种变电送电设备,电网部门以及电气公司均对变电站及其设备的接地性能给予足够的重视和研究。接地网在使用过程中容易受到腐蚀问题的困扰,尤其是钢材料的接地网,当腐蚀到一定程度,将增大接地电阻,使得整个变电站的对地电压升高,一旦发生雷击或者过电压等事件,将很容易对站内的工作人员和送变电设备造成损害,在不影响变电站正常运行的情况下,针对网络结构进行准确探测对于后续的故障诊断和接地网的定期维护都具有十分重要的意义。目前常见的接地网络探测方法主要包括电网络分析法、电化学检测法、电磁场检测方法等,宽频电磁法基于电磁感应原理,在探测方式上具有安全、高效、快捷等优点,研制宽频接地网络探测仪器具有实际意义。本论文在借鉴国外先进仪器的基础上,设计了基于DSP平台宽频接地网络探测仪,并实现了发射和接收样机的制作。发射部分采用DSP数据处理平台生成SPWM信号,经过电平隔离、驱动电路,控制逆变电路的MOSFET器件开关,生成交变电压,施加到发射线圈上产生固定频率的交变正弦电流。接收部分采用高精度AD采样芯片,通过前置放大电路、信号滤波电路,接收二次场信号,存储在设备中并传输至上位机进行处理。设计实现了系统软件部分,主要是基于DSP、单片机以及上位机软件的程序设计,包括脉冲信号的编程设计、DSP与模数转换芯片的数据传输DMA设计、接收信号的初步提取和计算、发射部分交互界面和单片机SD卡存储设计,并采用MATLAB软件设计了上位机的读取程序。最终对设计的发射和接收样机分别进行了测试,验证了设计的正确性。在室内进行了金属体和接地网模型测试实验,通过对测试数据的分析,验证了设计的有效性。
[Abstract]:In the process of substation operation, the protection of grounding grid is needed, the grounding grid can protect the personnel in the substation and all kinds of substation equipment. The power grid department and the electric company all pay enough attention to the grounding performance of the substation and its equipment. The grounding grid of steel material will increase the grounding resistance when corrosion to a certain extent, which will increase the ground voltage of the whole substation. Once lightning strikes or overvoltages occur, it will easily cause damage to the staff and power transmission equipment in the station, and the network structure is accurate without affecting the normal operation of the substation. Detection is of great significance for the follow-up fault diagnosis and the regular maintenance of grounding network. The common grounding network detection methods currently include electrical network analysis, electrochemical detection, electromagnetic field detection and so on. The broadband electromagnetic method is based on the principle of electromagnetic induction, and it has the advantages of safety, efficiency and shortcut in the detection mode. The development of broadband grounding network detection instrument is of practical significance. On the basis of foreign advanced instruments, this paper designed a broadband grounding network detector based on DSP platform, and realized the manufacture of the launch and receiving prototype. The launching part uses the DSP data processing platform to generate the SPWM letter number, through the level isolation, the drive circuit and the control of the inverter. The MOSFET switch of the circuit generates alternating voltage, which is applied to the transmission coil to produce the alternating sinusoidal current of the fixed frequency. The receiving part uses a high precision AD sampling chip, through the preamplifier circuit, the signal filter circuit, receiving two field signals, stored in the equipment and transmitting to the upper computer for processing. The system software is designed and realized. Part, mainly based on the program design of DSP, MCU and PC software, including the programming of pulse signal, the data transmission DMA design of DSP and analog to digital conversion chip, the initial extraction and calculation of the received signal, the interactive interface of the transmitter and the memory set of the SCM, and the design of the reading process of the upper computer with the software of MATLAB. The design is tested to verify the correctness of the design. In the laboratory, the test experiment of the metal body and grounding grid model is carried out, and the effectiveness of the design is verified by the analysis of the test data.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM63;TM862

【参考文献】