配电变压器低压侧无线式电流变送器的设计

发布时间：2018-01-07 05:32

本文关键词：配电变压器低压侧无线式电流变送器的设计　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：长期以来，窃电现象一直屡禁不止，窃电行为呈现出多样化、智能化、产业化等特点，这不仅给电力企业造成了严重的经济损失也扰乱了正常的供电秩序。当前，电力企业在反窃电过程中碰到的普遍难题是取证难、反窃电水平低，如何提升反窃电技术水平是摆在科研人员和稽查人员面前的重要课题。研制出一种智能反窃电稽查装置对于电力企业的反窃电工作具有重要的现实意义。本文研究的无线式电流变送器，是低压智能反窃电装置的重要组成部分，能将配电变压器低压侧三相输电线上电流信号采集并无线传输至稽查主机，与用户电能表电流参数进行比对，防止在配电变压器与计量电表间发生电流法窃电，从而填补了当前不存在反电流法窃电装置的漏洞。针对无线式电流变送器的功能部分进行方案设计，分析了方案中各个组成部分的原理及工作流程，根据设计要求对电流变送器进行软硬件实现，选择可插拔式的高精度Rogowski线圈作为测量探头，从而便于带电安装，并结合三相电表计量芯片ADE7878实现电流有效值计算，采用数字积分器和失调校准消除了时漂与温漂的影响，并设计低功耗控制模块实现系统低功耗。另外，设计了无线式电流变送器供能方案，分析了供能电源的基本要求，在对比了几种取能方式后选择了更加合理的取能线圈和电池供电相结合的供电方式。经磁场及磁路分析可知，开气隙可以有效解决磁饱和等难题。设计了后续处理电路，包括瞬态保护及过压监测电路、整流滤波电路、DC-DC电路、电源管理电路和可充电电池，保证取能电源可以长期稳定地供能，，并确保了取能电源能够适应输电线较宽的电流范围。对无线式电流变送器进行功能调试，结果表明电流变送器达到了低功耗、无线传输距离100m、测量精度小于3%的设计要求；另外，通过模拟取能线圈的输出电压，验证了取能电源后续处理电路能够稳定运行。
[Abstract]:For a long time, the phenomenon of electricity theft has been repeatedly prohibited, the behavior of electricity theft has shown the characteristics of diversification, intelligence, industrialization and so on. This not only causes serious economic losses to electric power enterprises, but also disturbs the normal order of power supply. At present, the common problem encountered by electric power enterprises in the process of anti-theft of electricity is the difficulty of obtaining evidence and the low level of anti-theft of electricity. How to improve the technical level of anti-electricity theft is an important task for the researchers and inspectors. It is of great practical significance to develop an intelligent anti-electricity stealing inspection device for the power enterprises. The wireless current transmitter studied in this paper is an important part of the low-voltage intelligent anti-theft device. It can collect the current signal from the three-phase transmission line on the low-voltage side of the distribution transformer and transmit it wireless to the checking host. Compared with the current parameters of the user's watt-hour meter, the current stealing between the distribution transformer and the metering meter is prevented, thus filling up the loophole of the current anti-current stealing device. According to the function part of the wireless current transmitter, this paper designs the scheme, analyzes the principle and work flow of each component of the scheme, and implements the hardware and software of the current transmitter according to the design requirements. The high precision Rogowski coil of pluggable type is chosen as the measuring probe, which is convenient for live installation, and realizes the calculation of the current RMS value with the three-phase meter metering chip ADE7878. Digital integrator and offset calibration are used to eliminate the influence of time drift and temperature drift, and a low power control module is designed to realize the low power consumption of the system. In addition, the energy supply scheme of wireless current transmitter is designed, and the basic requirements of power supply are analyzed. After comparing several energy extraction methods, a more reasonable power supply method is selected, which is combined with the battery power supply, and the magnetic field and magnetic circuit analysis show that the power supply method is more reasonable. The open air gap can effectively solve the problem of magnetic saturation. The following processing circuits are designed including transient protection and overvoltage monitoring circuit rectifier filter circuit DC-DC circuit power management circuit and rechargeable battery. It ensures that the power supply can supply energy steadily for a long time, and it can adapt to the wide current range of transmission line. The function of the wireless current transmitter is debugged. The results show that the current transmitter achieves the design requirements of low power consumption, wireless transmission distance of 100m and measurement accuracy of less than 3%. In addition, by simulating the output voltage of the energy extraction coil, it is verified that the subsequent processing circuit of the energy recovery power supply can run stably.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM421

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