低压电力用户远程自动抄表系统

第一章 低压电力用户远程自动抄表系统概述
1.1 配电自动化与低压电力用户远程自动抄表系统的概述
1.2 功能及常规模块的说明
1.2.1 实现的主要功能 【14】【15】
1.3 本文主要工作

第二章 通讯
本章所论述的是本系统的基础。本系统从总体上来说有四个通讯点：电表，采集器，集中器和微机主站。他们之间的关系有：电能表到采集器，采集器到集中器，电表到集中器以及集中器到微机主站。下面我先从几种常见的通讯说起，然后对各个环节进行具体的说明。
2．单片机给上位微机的回应数据包格式

第三章 采集器的硬件和软件实现
常规的系统其实是一个单向的系统，即抄表系统抄了用户的表后将数据送到管理部门，由管理部门进行核算操作然后收取电费，过期不缴的话再由远程抄表系统将其电切掉。这对于用户来说的话，就象是在一个黑匣子里运作似的，少了不少的交互性，从电力部门在市场上作为一个服务部门的角度来说，我觉得这是不够理想的。
在IT业飞速发展的今天，WWW技术已经与与数据库技术有了较为实用和可用的结合。电力部门作为一个传统行业，虽然它是生活中不可缺少的，但是我觉得他也应该跟上时代的潮流，者也是一个必然的趋势。比如在本系统中，我认为完全可以加上WWW技术。理由是这样的，首先我们的系统中已经有了一个数据库，微机主站也已经有了，WWW技术本身和数据库的结合的理论上来说是可行的，这样的话从硬件上的开销来说不会增加，而在软件上我们只需做到两点：WWW与数据库的接口和发布一个可以交互的网页。这两点都是不难做到的。
这样的话我们的远程自动抄表系统的全称就可以叫做"基于电力线载波的远程自动抄表PLUS用户WWW查询系统"。它提供的服务将是双向的，首先该系统可以采集用户的电量并将它发送给用电管理部门，而用户也可以通过登录用电管理部门的网站来查询自己的用电情况和电力部门的相关通知，这样电力部门和用户就可以有较好的沟通。这样我们的系统将从一般的系统中脱颖而出，可以大大的增加竞争力。
具体的方案是这样的，在传统的远程自动抄表系统上加上一部分，如上示意图的红色部分，这样就构成了一个闭环的系统。用户登录我们的网站，提交一张表，只需要输入用户名和密码，然后用户就可以在我们的数据库中查询自己的用电情况：它可以得到自己的用电曲线，该交的电费，以及最后的期限和停电的通知，如果可能的话可以实现用户的网上付费，这样的话就可以实现网上电力局的目的，我觉得是很有前途的。

参考文献
[1]邬宽明. 单片机外围器件使用手册. 北京航空航天大学出版社,1998
[2]陈宝江 等. MCS单片机应用系统使用指南. 机械工业出版社,1997
[3]王福瑞. 单片机微机测控系统设计大全. 北京航空航天大学出版社,1999
[4]薛均义 等. MCS51/96系列单片微型计算机及其应用. 西安交通大学出版社, 1990

致谢

THE ABSTRACT OF SOME DOCUMENTS
IN MY PROJECT,I USED MANY KINDS OF CHIPS.AND IN THESE CHIPS,I AM ESPECIALY INTERESTED IN TWO KINDS OF CHIPS:NON-VOLATILE RAM AND μP SUPERVISOR.
[NON-VOLATILE RAM]
NON-VOLATILE RAM IS A KIND OF CHIP WHICH CAN HOLD THE DATA EVEN IF THE POWER IS SHUT DOWN.GENERALLY SPEAKING, THERE ARE TWO KINDS OF NON-VOLATILE RAM:RAM PLUS EEPROM AND RAM PLUS BATTERY.IN THE WORLD,THERE ARE THREE BIG PRODUCERS OF THE NON-VOLITILE RAM.THEY ARE XICO,SIMTEK AND DALLAS.XICO AND SIMTEK PRODUCE THE RAM PLUS EEPROM AND DALLAS PRODUCES THE RAM PLUS BATTER.NOW LET ME INTRUDUCE THE TWO KINDS OF NON-VOLATILE RAM RESPECTIVELY.
RAM PLUS EEPROM. THIS KIND OF NON-VOLATILE RAM IS FABRICATED WHIH A PIECE OF ORDINARY RAM AND A PIECE OF ORDINARY EEPROM. THE NOVRAM DESIGN ALLOWS DATA TO BE EASILY TRANSFERRED FROM RAM TO EEPROM(STORE) AND EEPROM TO RAM(RECALL).THE STORE OPERATION IS COMPLETED IN A VERY SHORT PERIOD OF TIME AND THE RECALL OPERATION IS MUCH FASTER.THE MOST IMPORTANT THING IS THAT NOVRAM IS COMPATIBLE WITH INDUSTRY STANDARD RAMS,ROMS,EPROMS AND EEPROM.
NOW LET US TALK ABOUT THE DEVICE OPRITIONS.
RAM OPRITION:IT IS THE SAME AS ORDINARY RAMS;
NON-VOLATILE OPRATION:WITH NE (NON-VOLATILE
ENABLE) LOW,RECALL OPERATION IS PERFORMED IN THE SAME MANNER AS RAM READ OPERATION.A RECALL OPERATION CAUSES THE ENTIRE CONTENTS OF THE EEPROM TO BE WRITTERN INTO THE RAM ARRAY.THE TIME REQUIRED FOR THE OPERATION TO COMPLETE IS 5 US OR LESS.A STORE OPERATION CAUSES THE ENTIRE CONTENTS OF THE RAM ARRAY TO BE STORED IN THE NONVOLATILE EEPROM. THE TIME FOR THE OPERATION TO COMPLETE IS 5 MS OR LESS.
POWER-UP RECALL:UPON POWER-UP ,THE CHIP PERFORMS
AN AUTOMATIC ARRAY RECALL.WHEN VCC MINIMUM IS REACHED,THE RECALL IS INITIATED,REGARDLESS OF THE STATE OF SOME RELATIVE PINS.
WRITE PROTECTION: GENERALLY SPEAKING, ORDINARY
NON-VOLATILE RAM HAS FIVE WRITE PROTECT FEATURES THAT ARE EMPLOYED TO PROTECT THE CONTENTS OF BOTH THE NONVOLATILE MEMORY AND THE RAM.(TAKE X20C04 FOR EXAMPLE)
*VCC SENSE-ALL FUNCTIONS ARE INHIBITED WHEN VCC
IS 3.5V
*A RAM WRITE IS REQUIRED BEFORE A STORE CYCLE IS
INITIATED.
*WRITE INHIBIT---HOLDING EITHER OE LOW,WE HIGH,CE
HIGH,OR NE HIGH DURING POWER-UP AND POWER-DOWN WILL PREVENT AN INADVERTENT STORE OPERATION.
*NOISE PROTECTION---A COMBINED WE,NE,OE AND CE
PULSE OF LESS THAN 20 NS WILL NOT INITIATE A STORE CYCLE.
*NOISE PROTECTION---A COMBINED WE,NE,OE AND CE
PULSE OF LESS THAN 20NS WILL NOT INITIATE A RECALL CYCLE.
PREVIOUS WORDS ARE TALKING ABOUT THE WORKING
PRINCIPLE AND THE COMMEN OPRATONS ABOUT THE RAM PLUS EEPROM NON-VOLATILE RAM.
RAM PLUS BATTERY.THIS KIND OF NON-VOLATILE RAM IS
MADE UP WITH THREE PARTS:RAM,BATTER AND A COMPARE CIRCUIT.OBVIOUSLY,THE CIRCUIT IS THE KEY.USUALLY VCC IS CONNECTED TO THE POWER, WHEN POWER IS BELOW 4.5V,THE COMPARE CIRCUIT SWITH THE VCC PIN TO BATTERY AND WHEN THE POWER IS UP ,THE VCC PIN TO POWER.THAT IS TO SAY,THE CIRCUIT ALWAYS KEEP THE VCC PIN TO THE NORMAL SOURCE TO KEEP THE RAM WORK SAFELY.
THE PREVIOUW WORDS IS DICUSSING ABOUT THE NON-
VOLATILE RAM.
[μP SUPERVISOR]
NOWADAYS WE REQUIRE THE ELECTROLICAL DEVICE
MORE ROBUST,THE STABILITY AND THE ANTI-INTERRUPTION ABILITY OF THE MICRO-PROCESSOR AND DSP BECOME A BIG PROBLEM.AND THE μP SUPERVISOR TECHNOLOGY GIVES THE ANSWER.
Μp IS MICROPROCESSOR'S ABBREVIATION,IN IC INDUSTRY
SUPERVISOR MEANS THE CIRCUIT WHICH CAN SUPERVISE THE VOITAGE AND HAS THE ABILITY OF WATCHINGDOG,DATA PROTECTION AND BATTERY SWICHING.NOW I WILL INTRODUCE THE FUNCTIONS PARTICULALY.
POWERUP RESET.THIS FUNCTION ENSURES THE SYSTEM
CAN STARPUP CORRECTLY.
POWERDOWN RESET.WHEN THE VOLTAGE BELOW A
THRESHHOLD VALUE OR SHUT DOWN,A RESET SIGNAL WILL RESET THE SYSTEM.HOW TO CHOOSE THE THRESHHOLD VALUE IS VERY IMPORTANT.THE COMMEN THRESHHOLD VALUE IS 4.65V,4.40V,4.00V,3.08V,2.93V,2.63V ETC.FIRSTLY, YOU SHOULD KNOW THE NORMAL VOLTAGE AND THE LOWEST VOLTAGE THE SYSTEM NEED WHEN IT CAN WORK SMOOTHLY.THE RESET THRESHHOLD VALUE IS NORMALLY LIGHTLU LOWER THAN THE NORMAL VOLTAGE BUT HIGHER THAN THE LOWEST VOLTAGE.AND YOU HAVE TO THINK ABOUT THE ENVIRENMENT YOU SYSTEM WILL WORK IN,THE QUALITY OF THE POWER AND THE REQUIREMENT OF THE STABILITY.
WATCHINGDOG TIMER.WHEN THE PROCESSOR IS
INTERRUPTED,SO THAT THE PROGRAMS RUN WRONGLY AND RUN INTO A CYCLE,THE WATCHINGDOG WILL GENERATE A SIGNAL TO RESET THE SYSTEM TO MAKE THE SYSTEM WORK CORRECTLY AGAIN.THE WATCHINGDOG HAS THREE PARTS:WDI,WDO AND TIMER.THE WORKING PRINCIPLE IS:VALIDE WDI INPUT(HIGH-LOW/LOW-HIGH)WILL RESET THE TIMER;IF IN A CERTAIN PERIOD OF TIME THERE ARE NO VALIDE WDI INPUT THE TIMER WILL OVERFLOW AND GENERATE A SIGNAL WHICH WILL RESET THE SYSTEM THROUGH THE WDO PIN.
DATA PROTECTION.WHEN THE POWER SOURCE OR THE
SYSTEM WORK UNNORMALLY,THE MODULE WILL PROTECT THE DATA THROUGH THE WAY SUCH AS WRITE PROTECTION AND BATTERY SWITCHING.
POWER SUPERVISE.WHEN THE POWER WORK
UNNORMALLY,THE MODULE WILL GENERATE A SIGNAL TO TELL THE SYSTEM.
NOW THERE ARE MANY PRODUCERS WHO PRODUCE THE Μ
P SUPERVISOR SUCH AS ADI、 IMP、 XICOR、 MAXIM、 DALLAS ETC.
I THINK IF YOU CHOOSE THE RIGHT ΜP SUPERVISOR IN
YOUR SYSTEM,IT WILL WORK MORE SAFTELY,MORE STABLY AND MORE ROBUST.