手持式瞬态磁场记录仪硬件设计与实现

发布时间：2018-04-05 01:15

本文选题：智能变电站　切入点：二次设备　出处：《电子科技大学》2014年硕士论文

【摘要】：智能变电站中前移至一次设备近旁的二次设备将遭受更为严酷的电磁干扰环境,可能导致二次设备损坏,也可能因此造成保护设备误动作或不动作。掌握变电站的电磁环境,分析变电站电磁干扰的特征对抑制电磁干扰、保护二次设备和保护装置稳定运行具有重要的意义。现场测量的方法是研究变电站电磁环境的一种重要的手段。目前,变电站瞬态电磁干扰的测量系统并不常见,且在使用上具有较明显的局限性,因此,本文研制了一台适用于变电站瞬态磁场环境测量、记录及分析的手持式设备。该设备由磁场测量探头和记录仪主机两部分组成。磁场测量探头采用了基于AMR效应的磁阻传感器,而记录仪主机采用了基于FPGA+ARM+ARM的系统架构。论文先后完成了磁场采集模拟前端,数据中继引擎,人机交互单元,数据存储单元以及电源系统等电路的设计,其中,磁场采集模拟前端重点研究了交流通道和放大电路的设计方法,从理论上推导了增益分配对于输出信噪比的影响,数据中继引擎重点研究了FPGA与DDR2接口电路的设计方法,并通过仿真验证了设计的正确性。记录仪最终实现了磁场波形显示、大容量数据存储、离线分析、GPS时标、USB读卡器以及人机交互等功能。记录仪安装简单,维护方便,体型轻巧,便于携带,适合户外长时间工作。实验室工频磁场试验和脉冲磁场试验分别测试了记录仪工频磁场测试性能和瞬态磁场的捕获性能。试验结果说明记录仪能够对变电站正常运行时的稳态磁场环境以及变电站开关操作或系统故障等暂态过程时的瞬态磁场环境进行有效的测量。对锦屏-苏南±800kV换流站内部包括母线下方、交流滤波器场、GIS室、阀厅等在内的十余处位置进行的实地测量的结果表明,35KV低压电抗器附近磁场强度最大,峰峰值达到6Gs,而极I高端换流器出线口磁场频谱分量最丰富,FFT分析结果表明最高频率分量达到893.6kHz。
[Abstract]:The secondary equipment moving forward to the front of the primary equipment in the intelligent substation will be subjected to more severe electromagnetic interference environment, which may lead to the damage of the secondary equipment, as well as the maloperation or non-operation of the protective equipment.It is of great significance to master the electromagnetic environment of substation and analyze the characteristics of electromagnetic interference in substation to restrain electromagnetic interference and to protect secondary equipment and protective device from running stably.The method of field measurement is an important method to study the electromagnetic environment of substation.At present, the measurement system of transient electromagnetic interference in substation is not common and has obvious limitation in application. Therefore, a hand-held device is developed for the measurement, recording and analysis of transient magnetic field environment in substation.The equipment consists of a magnetic field probe and a recorder.The magnetoresistive sensor based on AMR effect is used in the magnetic field measurement probe, and the system architecture based on FPGA ARM ARM is used in the main computer of the recorder.The paper has completed the design of magnetic field acquisition and simulation front end, data relay engine, human-computer interaction unit, data storage unit and power supply system.The design method of AC channel and amplifier circuit is studied in the field acquisition simulation front end. The effect of gain allocation on output signal-to-noise ratio is deduced theoretically. The data relay engine focuses on the design method of interface circuit between FPGA and DDR2.The correctness of the design is verified by simulation.Finally, the recorder realizes the functions of magnetic field waveform display, large capacity data storage, off-line analysis of GPS timescale, USB card reader and man-machine interaction.The recorder is easy to install, easy to maintain, light and portable, suitable for long hours.The power frequency magnetic field test and the pulse magnetic field test in the laboratory are used to test the measuring performance of the power frequency magnetic field of the recorder and the capture performance of the transient magnetic field, respectively.The test results show that the recorder can effectively measure the steady-state magnetic field environment during the normal operation of the substation and the transient magnetic field environment during the transient process such as switching operation or system fault in the substation.The field measurements of more than ten locations in the inner part of the Jinping 卤Sunan 卤800kV converter station, including the bus, the AC filter field, the valve hall, etc., show that the magnetic field intensity near the 35 KV low-voltage reactor is the largest.The peak value reaches 6Gs, while the frequency spectrum of the output line of the pole I converter is the most abundant. The result of FFT analysis shows that the highest frequency component is 893.6kHz.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM63;TM937

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