【作者】 郭建春；

【导师】 方安安；

【作者基本信息】 南昌大学 ， 通信与信息系统， 2010， 硕士

【摘要】 随着我国进入新型工业化时代,用电需求在不断加大,低压配电网的规模也随之逐年扩大,安全用电就显得尤为重要了。目前,配电线路上负载的多样性大且电气特性复杂,特别是一些大功率非线性电气设备的接入,极易引起线路老化,导致火灾等特大灾害。电网电压的不稳定也会严重干扰精密工控设备的正常运行,由此而造成的经济损失是不可估量的。在这样的状况下,供电部门急需要一套可靠的智能监测系统来管理低压配电网。将GPRS无线通信技术应用于监测数据的传输,可以避免大规模铺设通信线路,实现对配电网的实时监测,从而为企业和居民提供绿色、稳定的电力供应。本文提出了一种基于GPRS的低压配电网监测终端的设计方案,它由数据采集模块和GPRS无线通信模块组成。数据采集模块负责配电网电能参数的收集、显示、存储和发布。无线通信模块通过RS232串口与采集模块相连,它主要负责将数据发送到后台监测中心。GPRS无线监测方式与传统的有线监测方式相比,有着更多的优点和更好的应用前景。目前相关的监测产品也有,但仍存在一些问题,所以厂家要求我们提出改进措施,以进一步提高产品档次。基于这一点,我们经过全面分析,决定实现配电网监测的三个关键技术(即高精度电能参数采集、自动回复查询短信和GPRS网络无断线连接),从而设计出具有如下优势的智能终端：(1)通过实际电路测量比较后,选用了高精度的CS5463型电能计量芯片来完成数据采集,与同类芯片相比,能精确测量更多的电能参数且具有温度漂移补偿等功能；(2)当GPRS模块收到新短信时,不存入SIM卡,而直接从串口输出至处理单元,完成查询短信的快速读取和自动回复；(3)采用最新软件“心跳包”技术,实现GPRS模块一直在线,避免反复连接网络。在硬件方面,我们采用STC90C58AD型单片机作为主处理器,它具有4kB的SDRAM,能很好地完成短信收发和GPRS网络连接。监测终端上还包含了显示、存储、时钟日历和按键控制等辅助功能电路。在软件方面,我们重点实现短信的编解码,使用AT指令实现GPRS网络的无断线连接,编写各功能电路的驱动程序。更多还原

【Abstract】 With our country entering a new era of industrialization, the demand for power consumption continues to increase, the scale of the Low-voltage distribution network is also expanding year by year and the problem of using electricity safely appears especially important. At present, the load of distribution line has different types and their electrical characteristics are complex, especially the nonlinear electrical equipment with high-power which can easily cause the wire to age and bring fire and other serious disasters. Voltage instability will seriously interfere with the normal operation of industrial equipment and the economic loss is incalculable. In such a situation, the power sector needs a reliable intelligent monitoring system to collect data used for the management of the Low-voltage distribution network. The GPRS wireless communication technology is applied to send monitoring data, which can avoid laying communication lines on a large scale and achieve real-time monitor of the network status, so as to provide green, stable power supply for corporations and residents.This paper gives a new method for the design of Low-voltage distribution network Terminal, which is based on GPRS technology. It is consisted of two parts: data acquisition module and wireless module. The first part is used to collect the power parameters of distribution network for display, storage and distribution. Wireless module connects with gathering module through the RS232 serial port and finally the data is sent to operation center via the GPRS network. Compared with the traditional wired monitoring method, the wireless method has more merits and better application prospect. At present, the related monitoring products have appeared, but there are still lots of problems crying out for solution. In the face of this, the manufacturers require us to make improvements and rise up the quality of the products. Considering this point, we decide to implement three key technologies through our comprehensive analysis, which are used for the management of the distribution network (how to collect the power parameters with high precision, how to reply SMS automatically, how to link the GPRS network without break). In order to solve these problems, we design the intelligent terminal with the following advantages. (1) Based on the actual measurements, we select CS5463 chip with high-precision to collect data. It can get all kinds of power parameters through calculation. Compared with the similar chips, the CS5463 chip can provide more parameters and compensate for the temperature drift. (2) When the GPRS module receives a new short message, it is not stored in the memory of SIM card but output from the serial port directly, so as to read the message without waiting and reply automatically. (3) Making use of the newest technology of heartbeat-packets to keep GPRS module on line all the time and avoid connecting to the network repeatedly.In the hardware design, we choose STC90C58AD chip as the main processor, which has 4kB SDRAM, can accomplish to process short message and link to the GPRS network. The monitoring terminal also includes auxiliary circuit used for display, memory, clock, calendar and key control. Regarding software design, we mainly achieve the message encoding and decoding, use the AT command to complete the access of GPRS network without break and write the driving program of the functional circuit.更多还原