2012 International Conference on Innovations in Information Technology (IIT)

Remote Energy Monitoring, Profiling and Control Through GSM Network Adnan Rashdi, Rafia Malik, Sanam Rashid, Anam Ajmal, Sulaiman Sadiq Department of Electrical Engineering, Military College of Signals, National University of Sciences and Technology, Islamabad, Pakistan [email protected], [email protected], [email protected], [email protected], [email protected],

Abstract—This paper presents design and development of a GSM based energy monitoring, profiling and control system. Our system integrates digital energy meters installed at consumer unit with an electric supply company’s energy monitoring system. Single phase or three phase digital electric meter can be used with indigenously developed add on transmission module, which takes the meter reading and utilizes the GSM network to transmit the energy usage reading using Short Message Service (SMS) back to the energy supplier. At the supplier end, an energy monitoring system is used to manage all received meter readings, compute the billing cost, update the database and maintain an energy consumption profile for each user. Various alerts and control can also be generated by the supplier. A simple, cost effective and reliable working prototype of complete system has been developed using digital energy meter manufactured by MicroTech Limited, Pakistan to demonstrate an efficient and transparent means of automatic meter reading, billing and notification through the use of GSM network. Keywords-GSM; AMR; SMS; Monitoring, Profiling and Control System

I.

INTRODUCTION

The conventional metering system requires the supplier company to send personnel who manually read and record the energy consumption, so billing can be done accordingly. The manual reading system suffers from a wide variety of disadvantages, which tenders it inefficient. It requires a large number of meter readers to collect reading from all consumers, hence the frequency of meter reading acquirement is low, that is, usually once a month. Moreover, with human involvement, it is prone to human errors as well as tampering of records. This leads to non-transparency in the metering system. To devise an efficient metering system, the concept of Automatic Meter Reading (AMR) and Energy Profiling System (EPS) [1-2] originated, which provide an effective means of energy consumption information collection, and its analysis, for accurate billing. A plethora of technologies can be utilized for the implementation of such a system, each having its own pros and cons. Radio frequency based EPS can make use of Handheld, Mobile, and Fixed network. In handheld and touch based EPS, a handheld computer equipped with a transceiver is used (radio frequency or touch) to collect readings, but it does not make optimum use of the AMR capable meters, as meter reading personnel are required. Mobile or Drive-by meter reading is another approach where a

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reading device is installed in a vehicle. Due to the short range of mobility, it again requires a team for collection of meter readings. AMR can also be implemented by making use of Power Line Communication (PLC) [3-4], but it has an inherent disadvantage of interference and noise, which deems it unreliable. Wi-Fi, ZigBee and 3G technologies [5-6] have also been used for transmission of metering information, but have not being widespread as they require installation of facility/ access points to cover the designated areas and thus do not provide a cost effective solution in existing environments. Our indigenously developed GSM transmission module induce transparency in the current meter reading system, by facilitating low cost real time monitoring of consumer energy consumption. Automation would lead to an efficient energy metering system by removing human errors. Our system also allows the energy supplier company to remotely control the consumer energy meter. A major feature is the inclusion of a user consumption profiling system, accessible to users and the energy supply company. By incorporating control coupled with profiling, the project aims at creating some degree of awareness among users, encouraging them towards conservation of energy. An additional feature explored is the traffic profiling using Global Positioning System (GPS) to indicating the location of consumers which is extremely beneficial if used in collaboration with sensor circuits to indicate meter theft. Most of these features were not available with system developed in [7].

Fig 1: GSM Energy Profiling System

II.

transmitted by energy meters. In order to get reading from the meters, the first task was to detect and count these pulses, which required the development of a basic pulse detector circuit, followed by summation of the number of occurrences of the pulses detected, and computation of the energy value accordingly.

SYSTEM DESIGN

For system development, the existing digital electrical meters were used and aim was to interface the meters to transmission module via a meter interface unit. The reception module receives the message, whereas, the server end application updates the extracted reading in the database in real time. The web application then makes use of this data to formulate the profile of users.

Fig 4: Illustration of Meter Interface Unit Basic Functioning

2) Sending Reading via SMS: The reading attained is transmitted to the server using GSM modem. The meter reading is sent after a definite interval, as required, such that after a certain number of units have been consumed, the transmission module will inform the server end of the energy consumed till then.

Fig 2: Prototype System Components

A. Energy Reading from Energy Meter The meters being used are single phase digital energy meters A283, manufactured by Microtech Limited, Pakistan. The Teridian SOC generates pulses that are in direct accordance with the reading, at a rate of 3200 pulses per kWh of energy consumed. Using this approach, the proposed system attains meter reading.

3) Receiving SMS at the User End: The meter interface unit is programmed to receive SMS sent from the server end, extract relevant information from it, and then act accordingly. This portion lays foundation for incorporating control in the system. The messages that are received are stored in the SIM memory as and when they arrive, and are received by the MIU serially. The microcontroller is programmed to interpret the extracted message, and then act accordingly to fulfil the requisite function. 4) Remote Shutdown of Energy Meter: A major feature of control has been incorporated in the system, which provides the server with a facility, using which, the supply company can cut off the energy connection of any user and reconnect it with equal ease, remotely, without the need to send someone do the task manually. It can be utilized in case of vacancy of tenants, or when the supply needs to be disconnected due to non-payment of bills. Moreover, if the supply company has a policy of placing restraints on the consumption, to rein the luxurious use as a measure for energy conservation, the defaulters can be penalized by cutting off their supply for a predetermined duration of time. A relay circuit is interfaced with MIU, between the mains supply and the meter for this purpose.

Fig 3: Internal Working of the Energy Meter

B. Meter Interface Unit (MIU) The meter interface unit is the component that is attached to the energy meters installed at the consumer end. It is responsible for getting readings and then processing them into a proper format, fit to be sent as SMS to the server end. It includes the SMS sending/receiving portion which sends the message the GSM network, and receives incoming messages. The very basic controller Atmel 89C52 was programmed to fulfil the function of the MIU. The meter interface unit was developed to perform a combination of tasks, listed below:

5) Polling: An added feature at the server end is that of Polling, which enables the server to poll the transmission end of the prototype to send the reading of the meter, at any time. It infuses flexibility in the system and adds to the control exercised by the server. The server has to send a message of ‘UPD_READ’ (Update Reading) to the consumer, to trigger response from the MIU.

1) Pulse Detector and Counter: The meter reading collection is based on the acquisition and counting of pulses,

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Today’s usage, Usage since Last Payment, Bill since Last Payment is updated on refreshing the page.

C. Transmission Module The transmission system utilizes the existing GSM network. GSM technology incorporates encryption hence the messages transmitted are secure. Dedicated SIMs or numbers would be utilized for the energy reading transmission since lack of service or network congestion cannot be afforded. Various users send timed messages containing their respective readings so that the server receives one message at a time and SMS is delivered without delay. D. Receiving System at the Server End In order to receive messages from the GSM modem connected at the server through the USB interface, a windows form application was developed in C#.Net. The application was developed with the following functions: x x x x x

x

Receive messages from the GSM modem Sift through the message and extract the consumer number and energy reading Upload the consumption readings into the database Detect usage exceeding threshold Detect location change of meter Alert the consumer of excess energy usage and/or meter theft via text message

Fig 6: Consumer page, viewed on login

2) Administrator Home Page: The administrator has the option to add a new user, view the existing users, manage the users or view energy consumption for all or individual users.

Fig 7: Home Page of Administrator

Fig 5: Application Form at the Server End

E. Database Management System The database is maintained using MySQL server, in which two tables are maintained. Real-time consumption table logs all energy readings, which is edited with each new received SMS. The users table keeps record of subscribers, which can only be edited by the administrator. The content of the received SMS is added as a new row in the consumptions table. F. Web Development A website was developed in php scripting language, with the purpose to generate the energy profiles of users, to view user records, energy consumption and billing information. The website may be accessed from any location by the consumer or the administrator making the monitoring and profiling system remote in true sense.

G. Additional Feature-GPS After reviewing literature about meter thefts, an additional feature was added to the system to counter these thefts. Location of the meter, as received by the Global Positioning System, is transmitted to the server end after specific intervals. The location received is compared to the location stored in the database, and in case of a mismatch, corresponding alert is generated. Use of GPS System in the system is an efficient measure that forestalls the meter theft, adding security to the system. III.

TESTING AND RESULTS

At the initial phase of the system development, the meter reading acquisition approach was tested by comparing the pulse readings against the reading displayed by the energy meter through a test load of 1000Watts. As the results proved the approach accurate, it was utilized for acquiring the meter reading.

1) Consumer Home Page: The homepage shows general information about the logged in user. Information such as

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The energy curve for any month is plotted for the specified user for the current year, in the form of a bar chart.

Fig 8: Testing of System with Load attached Fig 11: Yearly Consumption

The whole system once developed, was tested by operating three meters simultaneously, so their timing and synchronization of sending meter readings to the servers, could be tested. The three meters were programmed to transmit readings serially, one after the other, so the performance of the server end application could be tested.

IV.

ANALYSIS

A system of remote energy monitoring, profiling and control system has been developed which can efficiently utilize the existing digital meters and widespread GSM infrastructure. With the advent of digital technology, electromechanical meters are continuously being replaced by digital meters. Digital energy meters offer greater convenience to implement and establish automatic meter reading system electronically. To develop an efficient, reliable and effective system of AMR, various technologies have been utilized, analysed in Table 1. The developed project utilizes the wide spread and already installed infrastructure of GSM network. The store and forwarding features of SMS allow reliable meter reading delivery when the GSM signal is affected by poor weather conditions. Handheld, Touch-Based Mobile

Fig 9: Billing vs. Consumption

The testing phase provided accurate results, hence verifying the performance of the system. The profiling system generated accurate and elaborate consumption graphs, fulfilling its function maximally.

Fixed Network, Ethernet RF Network Power Line Communication Wireless Fidelity (Wi-Fi)

The profiling system is equipped with the feature to produce elaborate and illustrative curves, showing monthly and yearly consumption of energy, along with the billing info.

Transparent but requires manual meter reading Short range of mobility, requires team of readers Expensive infrastructure required Usually simplex (one-way) systems Inherent disadvantage of interference and noise Reduced coverage area, installation of access points required Table 1

Our proposerd remote energy monitoring system is an efficient, simple, compact, cost effective and completely automated system which provides location monitoring with interative web interface. System provides elaborate consumer profiling which helps transparent billing and consumption control of resources. The reliabilty of the proposed system has been enhanced using SMS delivery reports. REFERENCES [1] Fig 10: Energy Usage Curve

[2]

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Automatic Meter Reading Association (AMRA) website: http://www.amraintl.org/about/ Archnet Technology Ltd. (2001) Automatic Meter Reading System

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