基于LoRa智能电能表的研究与设计

发布时间：2019-04-28 20:37

【摘要】：电能是当前国家发展、社会稳定的重要能源,电力事业高速发展的同时也伴随着诸多的管理问题。同时城镇化发展使得城市建筑物越来越密集,高层居民楼陆续开建,现有短距离无线抄表设备无法满足远距离的抄表要求。改变当前的电能表电量抄写方式,研究新型远距离无线通信功能的智能电表对国家经济发展、社会稳定具有重要现实意义。现有电表电量抄写方案通信方式主要通过电力线通信或者RS485通信。这种通信方式需要专线连接,布线成本高不利于大面积推广使用,而依靠ZigBee等无线通信技术虽然能减少布线成本,但是由于其通信范围只适合短距离无线通信,所以也不适合远距离的电表抄写方案。基于此本文设计一款适用于远距离无线数据传输功能的单相预付费智能电表,其主要依靠SX1276无线通信芯片实现该功能。该电表采用LoRa调制技术通过天线收发数据,具有高可靠性,高抗干扰性以及中远距离传输数据等优点。LoRa技术传输距离能达到传统无线通信方式距离的数十倍。本文以单相预付费电能表为研究对象,基于微处理芯片FM3308、电能计量芯片RN8209C及SX1276无线通信芯片于一体设计一款CPU卡的预付费电能表。该电表要达到实现对用电用户预付费管理的要求,同时在保障电表具备高精度计量前提下能够实现远距离的远程通讯功能。本文从电能表硬件设计入手,分析了电表相关硬件单元电路,重点讨论以SX1276芯片为核心构建无线通信模块电路,并设计软件驱动硬件电路工作,满足数据正常接收的要求。同时对计量芯片计量原理,电能表校表原理做了分析讨论。在软件方面设计了预付费电能表软件总体流程,系统初始化程序流程,数据存储模块程序流程,电能计量和处理模块程序流程以及SX1276无线通信模块的软件程序设计。最后将SX1276模块与电能表进行通信测试,通信测试后对电能表误差进行了校验。测试结果显示电能表能进行正常无线通信,且该款预付费电能表计量精度误差等参数符合国际国内标准,进而验证了本方案所设计的智能电能表的可靠性。
[Abstract]:Electric energy is an important energy for national development and social stability. The high-speed development of electric power industry is accompanied by a lot of management problems at the same time. At the same time, the development of urbanization makes the urban buildings more and more dense, high-rise residential buildings one after another, the existing short-distance wireless meter reading equipment can not meet the long-distance meter reading requirements. It is of great practical significance for national economic development and social stability to change the current copying mode of watt-hour meter and to study the new type of intelligent watt-hour meter with long-distance wireless communication function. The communication mode of current electricity meter copying scheme is mainly through power line communication or RS485 communication. This kind of communication mode needs dedicated line connection, the high cost of wiring is not conducive to the popularization of large area, and relying on wireless communication technology such as ZigBee can reduce the cost of wiring, but its communication range is only suitable for short-range wireless communication. Therefore, it is not suitable for the long-distance meter copying scheme. Based on this, a single-phase prepaid intelligent meter for long-distance wireless data transmission is designed in this paper. It mainly relies on SX1276 wireless communication chip to realize this function. The meter uses LoRa modulation technology to transmit and receive data through the antenna, which has the advantages of high reliability, high anti-interference and medium-long distance transmission. Lora technology can transmit the distance tens of times as long as the traditional wireless communication mode. This paper takes the single-phase prepaid watt-hour meter as the research object, designs a CPU card prepaid watt-hour meter based on the microprocessor chip FM3308, electric energy metering chip RN8209C and the SX1276 wireless communication chip. The meter needs to realize the management of user's prepayment, and the long-distance communication function can be realized on the premise of high-precision measurement of the meter. Starting with the hardware design of watt-hour meter, this paper analyzes the hardware unit circuit of watt-hour meter, emphatically discusses the construction of wireless communication module circuit based on SX1276 chip, and designs the hardware circuit of software driving to meet the requirement of normal data receiving. At the same time, the measuring principle of measuring chip and the calibration principle of watt-hour meter are analyzed and discussed. In the aspect of software, the whole software flow of prepaid watt-hour meter, system initialization program flow, data storage module program flow, electric energy metering and processing module program flow, and SX1276 wireless communication module software program design are designed. Finally, the SX1276 module is tested with the watt-hour meter. After the communication test, the error of the watt-hour meter is checked. The test results show that the watt-hour meter can carry on normal wireless communication, and the measurement precision error of the prepaid watt-hour meter accords with the international and domestic standard, and then the reliability of the intelligent watt-hour meter designed in this scheme is verified.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM933.4

【参考文献】