Arabic Republic of Egypt
Minia University
Faculty of Engineering
Electrical Engineering Department
Automatic Meter Reading
(AMR)
Prepared by :
Ahmed El-Sayed Mohamed Sakr
Egypt , Minia Univ.
Electrical Engineering Dep.
Supervised By :
Prof. Mohy Al-Dein Azzam
Electrical Engineering Dep.
December 5, 2010
Contents :
Page
I- Abstract . -2-
II- Introduction . -3-
1- CHAPTER – 1 : Traditional meter reading systems disadvantages -4-
2- CHAPTER – 2 : What is the AMR ? -5-
3- CHAPTER – 3 : Benefits of AMR . -6-
4- CHAPTER – 4 : AMR construction . -7-
5- CHAPTER – 5 : AMR THEORY OF OPERATION . -8-
6- CHAPTER - 6 : DISADVANTAGES OF AMR . -12-
7- References. -13-
I - Abstract :
AMR (Automatic Meter Reading ) is the modern Power measuring device .it is being used in measuring electricity , gas , water consumption in many countries on the world since it has a lot of advantages that the old analog meters doesn’t have .
it has advantages in safety , real time measuring and time save as well as it has a better user interface and digital data analysis .
AMR appears in several types depends on measured data type and data transfer technologies . We can say that AMR is the best solution to measure , collect and analyze data for the Mega networks like the electricity transmission and distribution network in Egypt .
II - Introduction
In 1886 , the first ac transmission line was installed . Since this age , it was very important to measure the energy that consumers pay for . Hence , the first generation of power meters was found which we know as (Watt-Hour meter ) [1].
As most of us know , the first generation(traditional meter reading devices ) is being used tell now in many places .It has a lot of disadvantages that we will mention later .
To overcome this disadvantages we have to modify a new reading system that provides remote reading , safety , on-time readings and a simple user interface . That is what AMR provides successfully .
Power consumption reading and analysis using AMR has a lot of benefits which we will discuss in this papers .This benefits make it clear that this system will be used in most of the regions of the world in the next few years .
The first AMR system was created on 1974 on USA by Mr. Paraskevakos who used a technology developed on 1972 by Theodore George[2].
CHAPTER – 1
Traditional meter reading systems disadvantages:
• Highly Person dependant.
• Human errors cannot be avoided.
• Accessibility of meters in rural/ Agricultural zones.
• Energy Audits performed based on bill collection which is highly inaccurate.
• Billing done mainly on estimated/ monthly average basis
• Inability to monitor and control discrete loads
• Billing cycle requires excessive time.
• Meter data used only for billing, cannot help in analysis like demand analysis, energy audit, pinpointing losses, etc.
CHAPTER – 2
What is the AMR ?
AMR brings significant benefits to the customer by providing increased meter-reading accuracy, fewer estimated bills, rapid response to read requests, automatic leak detection and billing options and provides detailed usage information about individual sites, which allows the company to offer variable rates and encourage price -responsive behavior among customers[3].
AMR improves operational management by providing just-in-time meter replacement, tamper detection, remote access, and automatic scheduling of meter reading. In short, AMR will optimize cost savings and maximize efficiency while providing improved customer service.
By using AMR we overcome the disadvantages of the traditional meter reading devices , improve the control and data we have and make the consumer aware of the power consumption he have so he can limit and control the price he pay [4].
Fig -1 : AMR system .
CHAPTER – 3
Benefits of AMR :
n Ability to detect tamper events and outage occurrences.
n Remotely Connect/ Disconnect power supply through meter.
n Calculate transformer loading and sizing from interval data
n 15 minute interval data gives accurate load information for supply scheduling, switching operations, planning etc
n Consistent and granular data for improved accuracy.
CHAPTER – 4
AMR construction :
4.1 - Consumer side unit (CSU):
Fig-2 : construction of the AMR Transmitter unit .
Transmitter unit is used to send the meter reading to the receiving end. The data is send to the receiver end through RF channel. The transmitter unit consist of transmitter module, encoder HT12E, microcontroller AT89C2051 and display driver 74LS244.The pulses are given to the of microcontroller via optocoupler. For display the meter reading we are using seven segments. The supply which is given to the transmitter unit is +5 volt. The meter data is stored on the EEPRO memory unit .
4.2 - Server side unit (SSU) :
At the receiving side , a RF receiver collect the data transmitted from the consumer side , decode it , and transfer the decoded data to the server computer which analysis this data and insert it into the database .
CHAPTER – 5
AMR THEORY OF OPERATION :
5.1 Consumer side unit (CSU) operation :
The microcontroller receives the measured quantity as analog data from the energy meter port which is , in watt-hour meters , a potential and current quantities .The microcontroller is programmed to analysis this quantities then it display the reading in the LCD screen . When the server wants to collect the reading from the meter , it sends a message to the meter which receive it throw the antenna and the GSM modem connected with it . This message call the meter to wake up and then it makes a data frame consisting of the meter’s information and sends it to the server which collect them and store them in the database . The data collection can be done at any time or periodically such as hourly, daily, weekly or monthly.
5.2 Server side unit (SSU) operation :
First , the SSU send a waking message to the CSU to tell it to wake up and start preparing data . after the CSU response and send the data , the SSU collect this data , analysis it and make the computations needed , then it store them on the database of the company .
the SSU can reprogram the CSU and fully control it by sending connect/disconnect commands or applying remote energy management .This reprogramming and controlling processes is being done throw commands transferred throw the communication channel between the SSU and the CSU .
5.3 SSU – CSU communication :
5.3.1 Telephone communication :
Telephone lines are desirable from an economic point of view since most electricity users in the country have telephone service. The telephone system provides an ideal communication infrastructure for AMR systems due to simplicity of operation, quality of data, high noise immunity, reliability and low cost, both at the remote site and the central station.
Telephone communications AMR systems are categorized by the method of call initiation and initial data flow. The two most common forms are inbound communications and outbound communications.
5.3.1.1 Inbound communications :
With inbound communications, a unit at the customer site (usually the controller or a modem connected to the controller) dials in to the central station system at the company without first receiving an interrogation message. The remote site unit initiates the communication at a date and time programmed into the controller's memory. In the case of tampering or system malfunctions, a call can be initiated to the company's central station, where the alarm condition will be received and processed. This approach takes advantage of the fixed monthly charge for local calls that the customer is already paying. No additional telephone access equipment is required.
The disadvantages of inbound communications are that the company cannot obtain real-time data upon request, nor can the company reprogram the controller unit or issue control commands as in the case of connect-disconnect or energy management, should these capabilities be incorporated into the system.
5.3.1.2 outbound communications :
Outbound communications arc those where data communications are initiated by a central unit located at the company or at a local telephone company switching station. These systems respond to a query and require central telephone switching equipment and test trunk lines.
Telephone company involvement is required to enable the company's central station computer to dial out to a customer's remote unit without ringing the customer's telephone. The advantage of this approach is that these systems function in real time, as needed, which simplifies the implementation of demand load recording surveys, status monitoring, etc.
The primary disadvantages to an outbound communications approach are the capital costs associated with the telephone company's involvement and the recurring tariffs that telephone companies charge. An additional complication arises in geographical areas served by one electric company and two or more telephone companies.
5.3.2 Powerline Communication :
Powerline carrier communications take place over the same lines that deliver electricity. This technique involves injecting a high frequency AC carrier onto the powerline and modulating this carrier with data originating from the remote meter or central station.
Years of research, however, have not overcome the technical problems that preclude this medium from being a cost-effective solution over primary transmission lines. Powerline carrier techniques may be used successfully and cost effectively for short distances; i.e., from a customer’s meter to a pole or surface-mounted transformer. It is very expensive to pass this data through a distribution transformer and onto the primary distribution lines and the resulting communications is slow due to the narrow bandwidth and mono-directional meaning data is transmitted from the meter to the company but the company cannot send data or control signals back to the meter or associated devices at the subscriber side.
5.3.3 Radio Frequency Communications (RF) :
Radio frequency, or RF, systems make use of small low power RF transmitters or transceivers located at the controller. These may take advantage of licensed or unlicensed portions of the RF spectrum and the effective radiated power of the transmitter and the distances capable of being traversed will vary as a function of the frequency and power of the remote transmitters and the receiving strategies employed. A variety of system configurations have been field tested thus far. The most successful employs a mobile unit operated in a van that sends a wakeup and transmit command to the remote meter units in its range. The remote meter units pick up the signal and respond by sending back requested data to the van's computer for later uploading and billing. This system is commercially available for use with gas meters. A variation of this approach employs remote meter units that regularly transmit every few seconds and a small portable receiver connected to a hand-held data terminal. Two of the more exotic approaches (in 1992) involves use of a cellular telephone network system and satellite communications.
The mobile receiver approach suffers the significant disadvantage of being effectively mono-directional ; thus, communication cannot be initiated from the company's central office. Therefore, systems of this type have limited function and relatively low feature/function cost ratios and are not well suited for use by electric utilities.
The full-scale implementation of AMR requires that a data communication network be established that effectively links every customer with the company's central office. The actual amount of AMR related data and its frequency of transmission is very low. These factors contribute to the difficulties encountered in the economic justification of AMR systems. There are, however, a myriad of services and functions that can be accomplished through this communication system, some of which significantly reduce a company's operating costs and some of which can actually generate additional revenues. The incremental costs associated with incorporating these functions in the AMR system controllers is marginal. Payback can vary enormously. In theory, it is almost possible to finance a full-scale AMR system installation through the resulting costs savings and new revenue-producing services [5] .
CHAPTER - 6
DISADVANTAGES OF AMR :
The most effective disadvantages of AMR system are :
1- The economical charges that must be satisfied in order to replace the old traditional meters with the new AMR devices .
2- The cost of involving communication companies in the system in order to make a data connection between the SSU and the CSU because this companies acquire payments to let the distribution company use her system as said in part - [5.3] .
We can overcome this disadvantages by :
1- make economical studies to chose the best system to build .
2- Make the AMR units locally to cover the national needs and use the extra-production in exportation to make economical balance .
3- In Egypt , about 49 % of the communication companies are owned to the Egyptian government .If a deal is made between the Electricity Ministry and the Communication Ministry , it’ll be easy to overcome the second disadvantage with the lowest cost .
References :
1- “Electric power transmission”, Wikipedia , http://en.wikipedia.org/wiki/Electric_power_transmission , visited at 1st December ,2010 12.00 am .
2- “Automatic meter reading”, Wikipedia ,
http://en.wikipedia.org/wiki/Automatic_meter_reading , visited at 1st December , 2010 01:00 am .
3- “AMR: Automated Meter Reading ,Passive Line Component Offering” , Johanson Technology Inc , July 21st, 2009,P.1, USA .