Solution of Load Shedding and Control Theft in Energy Meter

Chapter 1

                          INTRODUCTION

 

1.         Problem Description

The Energy crisis is one of the major issues in Pakistan. Everyone is affected by the shortage of electricity, especially industries. Their production is adversely affected from load shedding. As a consequence, the cost of production and products has risen in the country. So power shortage is one of the key factors in increasing inflation rate of Pakistan. Efficient load management is one of the possible solutions.
There are two widely available alternatives of load shedding, UPS and generators, but the electricity acquired from these two sources is very expensive due to various mechanical and electrical losses, because they are converting other forms of energy to electrical.

The Cost of uninterruptible power supply (UPS) is very high. A single unit for domestic purposes can cost thousands of rupees. Similarly, a 3 kilowatt generator can set you back as much as by 50,000 Rupees. Open space is needed for ups system because batteries require proper ventilation to disperse their fumes when they are getting charged. The same is true for diesel or gasoline generators as exhaust gases are released when they are running. UPS batteries have certain life time depending upon maintenance and usage. The maximum span of UPS battery is generally two years (due to limited number of charge/discharge cycles available) then it has to be replaced, which contributes to its recurring costs. Similarly, a generator requires
periodic oil and filter replacements. You cannot run your loads continuously on UPS since it has a DC battery as a power source which will only last a few hours before it will require recharging. Same goes for the generator, as most generators can only run for a few hours continuously before they get over heated, plus a domestic generator can guzzle up to 1.5 liters of fuel per hour. Considering the fuel prices in the country it further adds to the problem. Moreover, commonly used inverters produce modified Sine waves on which the inductive loads do not perform at their full capacity and it affects the useful life span of electric appliances. Generators may produce pure sine Waves but as mentioned above, they tend to be very expensive to operate. The Efficiency of inverter used in UPS is not more than 75%, besides the charging and discharging cycles of battery have their own losses which accumulate to total Efficiency of 65%, as a result UPS system must draw more power from the grid in Order to keep its batteries charged all the time. If we see all these factors on a large Scale, these factors contribute in a significant loss of electrical energy.

In a country like Pakistan, we are faced with many challenges. Energy theft is one of them. The generated electricity does not completely reach its consumers. There are many reasons behind the wastage of that electricity. Transmission line losses, distribution losses, energy theft etc, are among them. Energy theft is the major reason.

According to the survey in 2014, WAPDA faces 35% losses of its total in generation and distribution, which includes 21% technical loss and 20%, is due to illegal usage of electricity. Our government has invested a lot in the generation of electricity. The only way to get that investment back is by charging the consumer will pay for the electricity which they have used. The energy losses are not accountable and paid. This is a great burden on our economy. Therefore, every year WAPDA is in a loss.[1]

There should be a mechanism which identifies power theft and manage the domestic load. In this way, we can minimize the losses and increase the power sector productivity in Pakistan.

2.         Project Background/Overview

The Smart meter is not a new concept in this age. Most smart meters have advanced features like automatic meter reading or apparent load measurement, but load management and theft control is a new concept.

In this project, we are introducing a solution of load shedding and control theft in energy meter. For load shedding control we are giving limit for Domestic users (e.g:1kw power). That consumer which exceeds the set limit of power will result in a power cutoff (during peak hours). If a consumer try to steal the power without paying the actual charges by tempering the energy meter. Message will be sent to the power  company so that they will take action against the consumer. We also introduce the automatic billing system is this project the monthly bill sent to the consumer at the end of every month via GSM. The main concept of this project is to save energy.

The key benefit of this project is that the electricity consumer will be able to have some electricity available all the time. This eliminates the need of a UPS or a generator which will result in substantial savings to the end consumer and would be more convenient. It will also save the energy wastage in running the UPS and charging the battery and billing system improved as Consumers will not be issued any erroneous electrical bills.

3.         Project Objectives

For the device to work the present method of load shedding has to be altered, instead of shutting down the electricity of a particular area through a grid station, electric utility will communicate with all the devices of an area through the GSM Module. Utility will send a message containing specific instruction to a meter and depending upon that instruction the meter will act. Our main objective and focus is that at the time of load shedding meter will shut down all the heavy loads of a home and simultaneously it will also send a message to the customer about load shedding.

We have defined power limit for each consumers those consumers which exceed the limit during peak hours will result in a power cutoff and inform the user via message.

In case of power theft at the domestic end the message will be sent to the power company via GSM to take action against the consumer whom steals power. The message will be sent through GSM to the user and Power Company after user consumes energy (auto-billing system).

1.4 Project Scope

Project scope is very broad because energy crisis in Pakistan is prevailing from many Years. Production of electricity will not increase significantly in the near future. Load Shedding duration in summer reaches almost 10-12 hours in urban areas while rural Areas suffer almost 16-18 hours of load shedding. According to a survey, more than 24% of Pakistani populations have either a UPS or a generator in their homes, and as Previously explained UPS and generators are not very good substitute of electricity.

Our device has no such limitations. Its cost is slightly more than a normal standard energy meter. Unlike UPS or generator it will not require periodic maintenance and battery replacement .This makes the device very convenient for an end consumer. This is a whole new concept of load management and this method will reduce the cost of energy.

By implementing this system saves electricity and minimized the energy theft at the domestic end. There are many reasons behind the electrical losses i.e. Transmission line losses, distribution losses, energy theft at domestic end. This system will alert the electric company when the tempering in energy meter occur.

                                  

Table 1-1 Transmission and distribution losses in Pakistan

CHAPTER 2

                       LITERATURE REVIEW

2.1 Electricity Meter

An energy meter or electricity meter is a device that is used for measuring electrical

energy consumption; it is designed to measure

electrical energy used over a particular phase of time by a residence, business or industrial establishments like factories and workshops etc. The most common unit to measure electricity is kilowatt hour. Meter readings are taken periodically, usually at the end of a month. Figure 2-1 shows a typical modern day energy meter.

To register power consumption every home, factory, office must have at least one energy meter installed.

The electricity production houses sell electricity to           Figure 2-1 Energy Meter

distribution companies and these companies provide the electric energy to its customers via grid. Customers are obliged to pay the electric utility the amount against their bill.

2.2 History of Energy Meters

2.2.1 Direct Current Metering

Electric energy at first was popular in DC form, as early as 1880s.

With the spread of DC grid it became necessary to properly bill customers for the cost of energy. When Edison Illuminating Company was established on 17 Dec 1880, Edison made an        Figure 2-2 Reason Meter

electrochemical Meter system for measuring electrical energy. In this meter he used electrolytic cells which were removed and weighed after periodic intervals; depending on the weight of the plates the customers were billed. This operation was very labor intensive due to which electrochemical meter did not catch on.[2]

Another type of electrochemical meter known as “Reason meter” (shown in figure 2-2) was used to measure electricity in UK. In this method there was a glass structure with a mercury tank at the top of meter. Due to electrochemical action mercury transferred to the bottom of the column when the current was drawn from the supply.

When all the mercury was transferred to the bottom, the meter became an open circuit. After the dues have been paid the electric supplier’s agent unlocked the meter and restored it. Like all DC meters of that time, it recorded current in ampere-hours.

Ferranti made a mercury motor meter in 1885.

The main advantage of the meter was that the customers could easily read the meter and verify it. Dr. Hermann Aron invented first accurate energy meter in 1888. This type of meter (shown in figure 2-3) recorded the total charge used over a particular period of time,

and presented it on a series of clock dials          .Figure 2-3 First Accurate Energy Meter

Unlike AC meters, DC meters measured charge in amp-hour instead of energy in Watt-hours. Since the supply voltage remained significantly constant the energy consumed was directly proportional to the reading.[3]

2.2.2 Alternating Current (AC)

After Nickola Tesla won the famous “war of currents” alternating current became the standard for the transmission of electrical energy. This meant a new type of metering system was required. The first AC meter was made by Otto Blathy in 1889. In the same year, Elihu Thomson successfully developed a watt-hour meter based on an ILC Figure 2-3 First Accurate Energy Meter motor. The fundamental advantage of this meter was that it could operate on both AC and DC. Around 1894 Oliver applied the induction principle to make a watt-hour meter. His design was based on an induction disk with rotational speed directly proportional to the power delivered to the circuit. It worked only on AC and it also eliminated the use of commutation in Thomas’s design.

2.3 Unit of measurement

Most widely used unit of measuring energy is kilowatt hour. One kilowatt-hour is equal to the quantity of energy utilized by a load of one kilo-watt in one hour.

In some early meters the amount of charge were used to calculate electric energy if  and only if the amount of voltage supplied remains constant. Some meters only computed the amount of time for which the load was on. This is only suitable for a constant load.

In case of alternating current, besides real power, reactive power is also considered. It is calculated in thousands of volt-ampere reactive hours. Capacitive load have negative reactive power while inductive load have positive reactive power. Power factor tells us the ratio of resistive load over reactive load. Ideally, it should be equal to one. Since most of the load is inductive, capacitor banks are used to balance power factor.

2.4 Types of meter

Energy meter continuously measures the instantaneous voltage, current etc. Meters are connected directly on the line between source and consumer for smaller services such as homes etc. For loads of more than 200 amp current transformers and potential transformers are used. There are two main categories of meter:

• Electromechanical.                                       Figure 2-4 Inside an Induction meter
• Electronic.

 

2.4.1 Electromechanical meters

Electromagnetic induction meter is the most common type of electricity meter. Induction type energy meter have four main parts, namely driving system, braking system, counting and registering system.[4]. They are as follow

• Driving system
• Braking system
• Counting and registering system

• Driving system

Two electromagnets form the driving system. One is a series magnet and the other one is shunt magnet. Pressure or voltage coil have a large number of turns of fine wire and is wound on the center of the shunt magnet. Similarly current coil is wound on the center of series magnet.

Fluxes produced in voltage and current

coils are proportional to voltage and current respectively. Due to inductive nature of voltage coil, its field is delayed by 90 degrees, which is calibrated using a lag coil[5]. The combined effect of these coils produces eddy currents in the disk; as a result a force gets exerted on the disk which is proportional to the product Figure 2-5 Showing the Voltage and Current Coils

of voltage and current and the phase angle between them. Figure 2-5 is showing voltage and current coils and also a braking magnet that is a part of the breaking system.[6]

• Braking System

Small permanent magnet is located directly opposite to the electromagnets (consider figure 2-5). The disk sits between the magnetic fields. The rotation of disc in magnetic field produces an opposing torque which retards the disk rotational speed. Due to the equilibrium between these two opposing forces disc rotates at a speed proportional to energy consumption.

• Counting and registering systems

Counting system consists of a series of gears which are connected to their respective dials; the left most dial is analogous to least significant bit in a register, similarly right most dial is analogous to most significant bit           Figure 2-6 Counting and Registering Systems

Numbers from 1 to 10 are inscribed on each dial. One full rotation of a dial moves the dial next to it by 1/10, essentially making a decimal counter. This counter is driven from a worm gear on the disc such that the dials represent the number of rotations of the disc [7].

2.4.2 Electronic meters

The conventional electromechanical meter worked on the

principle of magnetic induction. As we know it has many

mechanical parts, so it is prone to mechanical defects and

breakdown. Electronic Energy Meter (EEM) is based on

solid state electronics. Since there are no moving parts, Figure 2-7 Electronic Meter

it is also called static energy meter. IC designed specifically for metering purposes, called ASIC (Application Specified Integrated Circuit) is employed in EEM.[8] Furthermore voltage and current transformers are also used for scaling purposes. The input voltage is collated with a reference voltage and ultimately a voltage value is provided to the output. Analogue to Digital converters are used to convert analogue values to digital ones. An electronic meter is shown in figure 2-7.

The digital data is transformed into an average value. Average value or mean value is

used for measuring the power. The output of ASIC is presented on LCD or LED

display and also in the form of pulses indicated by LED located on the front panel of

the meter. These pulses are equal to the average kilowatt- hours.[9]

Different electric meters are as follow.

• Smart meters
• Automatic meter reading
• Time of day metering
• Net metering

• Smart meters

Smart meters are the latest version of energy meters. They tell

energy usage in more detail than a normal energy meter. They

have the ability to communicate via wireless or a wired network

to the utility. One technological challenge faced by all smart

                                                                                                                                   Figure 2-8 Smart Meter

meters is communication. Each meter has to transmit the collected information to some central location through some reliable and secure method [10]. There are several techniques used in different countries depending upon the environment and locations. PLC (Power Line Communication, not to confuse with Programmable Logic Controller), Satellite links, Radio, Cellular and pager networks are proposed methods.[11]

The type of network is also a very crucial factor. Mesh networks, fixed wireless or

other internet related networks are also used. Figure 2-8 is showing a typical smart

meter which is in used in Europe. Smarts meters have multiple advantages over normal energy meters. Some are as under:

• Control on the limit of power consumed
• Can provide reading at any time
• Can warn against tampering attempt
• Can be used to enforce multiple rate options and time of use metering
• Communicate with devices inside the home
• Net metering
• Provide interval data
• Provide an outage signal

• Automatic Meter Reading

One of the key innovations in smart meter is automatic meter reading. Data is gathered automatically to the central data base for billing or analyzing purposes. This

technology has many advantages. It allows the utility to get all of the relevant information about customer’s meter without any regular trips to each consumers home to read a meter. This helps the customer as well as utility to get better control on the use and production of electricity. There are many benefits of advanced metering system.

• Increased efficiency.
• Power outage detection.
• Discourages meter tampering.
• Reduction in labor cost as a result of automated reading.
• Consumers can manage their energy consumption.
• Utility can remotely shut down electricity in case of non-payment.

• Time of day metering

Time of day metering is a technique in which utility companies divides the time slots

into different parts, with higher tariff rates at peak hours and low tariff rates at off-peak hours. Time of day metering system discourages the users to use electricity

during peak our which helps in lowering the overall peak demand. It is very helpful in

load management; it also allows the utility companies to better plan their transmission

infrastructure. This scheme also helps to better reflect the cost of electricity generation.

• Net metering

If an electricity consumer is producing surplus amount of electricity at home using

renewable energy then he/she can supply the extra amount of electricity back to the

grid. [12]The user will only have to pay for the net units consumed, which means total number of units minus number of unit sent back to the grid. If this results in negative units, than utility pays to the consumer.

2.5 Uninterruptable Power Supply (UPS)

The function of an uninterruptible power supply is to deliver emergency backup

power when the main input power supply fails. Unlike an auxiliary or emergency

power system a UPS will provide near instant safety from input power interruptions,

by delivering energy stored in batteries. Normally UPS consists of these parts: Inverter, rectifier, charger, static switch or a relay and battery.

 

2.5.1 Normal Operation

The rectifier transforms the AC power to DC power with regulated voltage during

normal operation. The DC filter is used for smoothing purpose of the rectifier output

current to minimize the current ripple factor. The function of the inverter is to convert

the dc power to ac power with regulated frequency and voltage. By controlling the

timing of the SCR firing signals the input frequency is matched, this is done through

an internal oscillator.

2.5.2 Loss of normal power

When there is no AC power the battery provides DC power to the inverter. Battery

will supply non-stop current to the inverter until and unless either the ac supply is

back or battery charge ends. So in this way inverter continuously supply power to the

loads.

 

2.5.3 Restoration of Power

When the mains power is back online, the rectifier output voltage is set at the

equalizing voltage to recharge the battery. The inverter acts as rectifier while

recharging the battery.

2.6 Generators

Generator is an electrical machine that converts mechanical energy into electrical

energy. When the output of the generator is connected to a load it completes the

circuit, a current is forced through the circuit driving the load. The mechanical energy

source may be a reciprocating engine or a steam turbine, water driven turbine as in

case of hydral power generation, an internal combustion engine, a wind turbine,

compressed air or any other source of mechanical energy. Generators are the source of nearly all of the electricity produced in the world. In the case of load shedding various corporations, industries and domestic electricity consumers use internal combustion engine (engine-generator) driven generators as their power backup.

 

 

2.6.1 Engine-generator

A motor generator is a mix of an electric generator and a motor (prime mover) to

shape a solitary bit of hardware that creates power. The motors utilized are normally

cylinder motor. A wide range of forms of the motor generators are accessible, from

little fuel controlled sets to extensive turbine establishments. The principle preferred

standpoint of motor generators is the capacity to autonomously give power, so that these machines serve as the reinforcement power arrangements.

2.7 Factors That Influence Illegal Consumers

There are many factors that encourage people to steal electricity. Of which socio- economic factors influence people to a great extent in stealing electricity. A common notion in many people is that, it is dishonest to steal something from their neighbor but not from the state or public owned utility company. In addition, other factors that influence illegal consumers are:

• Higher energy prices deject consumers from buying electricity. . In light of this, rich and highly educated communities also steal electricity to escape from huge utility bills.

• Growing unemployment rate show severe

2.7.1 Methods of Thefts

Methods used to commit theft fall into the Following broad categories:

a. Connection of supply without a meter Connection of supply without a meter following disconnection for non-payment or by “squatters” occupying empty properties.

b. By passing the meter with a cable. It coveted into the supply side of the metering installation (i.e. the meter terminals, the metering cables, the cut-out or the service cable).

c. Interfering with the meter to slow or stop The disc, including use of electrical devices which stop the meter or cause it to reverse (so-called ‘black boxes).

d. Interfering with the timing control Equipment used for two rate tariffs to obtain a cheaper rate.

Methods (c) and (d) usually involve removal of official (certification) seals and/or company seals. There effect on the customer’s economic situation.[13]

2.7.2 Effects of Electricity Thefts

Negative effects of electricity theft are severe and dangerous. Primarily, electricity theft affects the utility company and then its customers. In addition, electricity theft overloads the generation unit. In energy market, utility companies expect their money back from the customers for the electricity supplied, most of which is lost by them due to the NTL (Non-technical losses).Electricity theft is a serious concern for utility companies as they are under threat of survival because of these incurring economic losses. It is evident that some utility companies in developing countries are losing about 10 to 30 percent of their total revenue, which shows that they could not invest on measures to reduce the electricity theft. These economic losses affect the utility company’s interest in development of the devices in view of improving the quality of supply or for electrification process.

 

 

 

 

 

 

 

 

 

 

 

 

CHAPTER 3

 

                  REQUIRMENT AND SPECIFICTAION

3.1 Existing System

 

In Pakistan there is no concept of smart meters digital energy meter and mechanical energy meter are used at the domestic end. Only smart meter are used in few grid station of Pakistan which only deals with the control room and the grid.

Tremendous work has been done on smart energy meter especially for the control of

electricity theft and automatic meter reading. The present smart meters don’t have

load management system. People have to rely on UPS in case of load shedding. This

is one of the major limits of present smart meters. These smart meters have the

features like automatic meter reading and tamper protection.[14]

This project aims at the all 3 dimensions that is automatic meter reading, control

of power theft and  load management of a home with the help of smart energy meter. We are controlling the each house load individually by giving limit of power (during peak hours) if the consumer exceed the limit than the power cutoff of that user while all other users of that area using power without interruption because they have not exceed the set limit of power .Utility have the real time data of every meter connected to it. If someone violates the limit of load, meter will automatically shut down all the load of a home.

3.2 Limitations of the existing system

• There is no concept of load management in smart meters.
• At the time of load shedding the entire area will shut down.
• People use UPS or generator as alternators of electricity.

3.3 Proposed System

The proposed solution will improve the functionality of above mentioned system:

• Introduce Load management system.
• Load shedding will be done through GSM module rather than

from the grid.

• Theft detect (meter tempering alert) by using Vibration sensor and alert message sent through GSM to the Electric company.
• AMR (Automatic meter reading) system will make the system user friendly. And Consumers will not be issued any erroneous electrical bills.
• Eliminates the use of UPS or generator in case of load shedding.

So the proposed solution comes to be

“GSM Based Load Management and theft monitoring System”

3.4 Requirement Specifications

Requirements for “Load management and theft monitoring system” are:

3.4.1 Arduino Mega

The Arduino Mega 2560 controller configuration is based on mega 2560. The Mega 2560 have 54 digital input and output pins of which 15 can be used for PWM outputs. It consists of 16 analog inputs

• It have 4 UARTs (hardware serial ports),
• At Mega has  16 MHz crystal oscillator[15],
• A USB connection to connect with any device like computer etc
• A power jack
• An ICSP header and a reset button.

At Mega 2560 contains all things that is needed to guide the micro controller. Simple connect it to computer with AC-DC adaptor to get started. It is fit with most shield construct for the UNO and the previous board’s diecimila.

Figure 3-1 Arduino mega board

 

 

3.4.1.1 Features

 

 

 

 

 

 

 

 

 

 

Table 3.1 features of Arduino mega

 

3.4.2 Current Sensor (ACS712)

The Allegro ACS712 provides economical and accurate solutions for AC or DC current sensing in industrial, commercial and communication systems. The device consists of an accurate low-offset linear Hall sensor circuit, which is located near the die surface. The applied current flowing through the copper conduction path produces a magnetic field that is induced by the integrated Hall IC and converted to a proportional voltage. The device accuracy is optimized by positioning the magnetic signal near the Hall sensor. The exact proportional voltage is provided by the low offset, chopped-stabilized BiCMOS Hall IC, which is programmed with precision after encapsulation. The ACS712 Current Sensors offered on the internet are designed to be easily used with micro controllers like the Arduino. These sensors are based on the Allegro ACS712ELC chip. These current sensors are offered with full scale values of 5A, 20A and 30A. These sensors are used to measure the current.

 

 

 

 

                                        Figure 3-2 ACS712 (Current Sensor)

3.4.2.1 Sensor Specification

                                                      Table 3-2 ACS712 Specification

 

 

3.4.3 Potential Transformer

 

The capacity of potential Transformers is to gauge voltage in electrical force

Frame works. Much the same as CTs, they are intended to downsize the high voltages

to a level where it is good with the measuring hardware. As to venture, we have

utilized 3 ACS712 sensors and a PT for current and voltage estimations in our sensor module.

Figure 3-3 potential transformer

 

 

3.4.4 LCD

LCD is the truncation for Fluid Precious stone Presentation. It is an instrument that

shows the information on it by utilizing light regulating property. It is the element of

fluid gems. It is dainty and level in design and does not discharge light.

LCDs have an expansive utilization as they are utilized as a part of different tasks,

applications, frameworks and so forth. These days, they are extremely regular being

used and can be found in PCs, TVs, toys, amusements, timekeepers, watches, phones,

mini-computers and so forth.[16] Truly cathode beam tubes were utilized rather than

LCDs. Presently LCDs have supplanted them on account of their easy to use show,

simple use, minimal effort, transportability, light weight, high effectiveness and

unwavering quality. LCDs are accessible in numerous sizes. We have utilized two, 20

cross 4 alphanumeric LCDs in our keen meter for information and status

representation.

5.   GSM Module

A GSM module is a chip that will be used to establish communication between a mobile device and a GSM system. The modem is a critical part here. These modules consist of a GSM module powered by a power supply circuit and a communication interface for the computer (e.g. RS-232, USB 2.0, etc.). A GSM modem can be a dedicated modem device with a serial, USB connection, or it can be a mobile phone that provides GSM modem capabilities.[17].

A GSM module is a wireless modem that works with a GSM wireless network. AT commands are used to control modems. Operations Performed by GSM Modem are:

• Reading, writing and deleting SMS messages.
• Sending SMS messages.
• Reading, writing and searching phone book entries

Figure 3-4 GSM Module

3.4.6 Relay

A relay is simply defined as an electro-mechanical switch that is actuated by an electrical signal. Relays play an important role in many applications due to its comparative ease of use, durability and verified high consistency. The current flowing in one circuit causes the opening or closing of the other. All relays have an electric coil, which is powered by AC or DC current. When the applied current or voltage crosses a certain limit, the coil operates the switch, which either closes the open contacts or opens the closed contacts.

7.   RTC(DS1302)

A real-time clock (RTC) is a computer clock that keeps track of the current time. RTCs are present in almost any electronic device which needs to keep accurate time.

Figure 3-5 RTC (DS1302)

Real-time clock (RTC) ICs measure time, even when the power of the main device is off. During these times, RTC ICs draw power from an auxiliary battery or super capacitor.  As expected, power consumption is a key factor in most RTC designs, but accuracy and small package size are also important. Most modern RTC ICs reduce package pin count by supporting a serial interface. By using RTC we set the time and date in order to achieve our objective on the set time that is monthly billing and load management during peak hours.

3.5 Design constraints

In any design system there are always tradeoffs and design constraints. Our system is

no exception. Following are the sighted design constraints:

• Since we are controlling the load at consumer’s end therefore, for the smart

meter to work, load shedding cannot be done by traditional method i.e. shutting the electricity of a particular area via grid.

• At the time of load shedding only those consumers effected whom violate the set limit of power in a result of power cutoff of that consumer house by shutting down the meter.
• Tempering alert message sent to the power company control room at the time of any illegal activity with the meter done.
• Monthly bill sent to the user via message with the help of GSM module.
• Smart meter will work in those areas where network coverage is available at all time.

 

 

 

 

 

 

 

 

 

 

CHAPTER 4

                           SYSTEM DESIGN

 

4.1 System Architecture

This is the high level diagram of our system.

Figure 4-1 Block Diagram of the Working of the “Load Management and theft monitoring system”.

 

 

We are using switched mode power supply to provide power to our system

The mains supply input (230 VAC) is passed through the sensors module which houses the sensors (ACS712 & PT). ACS712 and PT are measuring current and voltage respectively and they are interfaced with Arduino Uno. Arduino Uno is calculating power from the corresponding voltage and current and displaying the results on LCD. Up to this step our smart meter calculating power consumedby the load and also detecting the theft by the help of Vibration sensor which alert the power company when someone try to temper meter and also this system have AMR automatic meter reading system which calculate the unit consumed by the consumer by the help of IR Encoder which read the revolution of the meter disc. For load management and theft monitoring purposes we have interfaced GSM module and connected the loads through relays. We are introducing a solution of load shedding by automatically  manage the load whenever the consumer exceed the set limit of power will face load shedding while other consumer not effected from load shedding whom not violate the set limit during peak hours.

4.2 Low level Diagram

In this section we are going to explain you how different modules are interfaced with

each other.

4.2.1 GSM Module Flow Chart

Figure 4-2 GSM Interfacing Flow Chart

 

When tempering detect in the energy meter the message will be sent to the electric company by using GSM. It also deal automatically by the help of controller when the consumer exceed the set limit of power will result in a power cutoff. The Monthly bill is also done by the help of the GSM.

4.2.2 Energy Calculation Flow Chart

Figure 4-3 Pulse Calculation Flow Chart

 

Energy calculated by the help of IR encoder which place near meter disc and we mark black spot on the disc so that IR encoder observe the black spot to detect the disc rotation, we use IR sensor to calculate the mechanical rotations of meter (480rev/Kwh=1unit) and display unit on LCD and in this way we are calculating energy and the monthly billing done on the basis of the total unit of energy consumed by the consumer.

 

 

 

4.3 Tempering Alert Theft Detection

For tempering alert we are using Vibration sensor. Vibration sensors are sensors for measuring, displaying, and analyzing linear velocity, displacement and proximity, or acceleration

Figure 4-4 Vibration sensor

 

 

4.3.1Working and dimension of Vibration Sensor:

 

 

 

 

4.4 Potential Transformer Interfacing

 

                                                Figure 4-5 PT interface with Arduino

The potential transformer gives yield as air conditioning voltage so there is no requirement for a weight resistor, however an inclination of 2.5 volts will even now be should have been given to the yield of PT so that, it gives yield somewhere around 0 and 5 volts. The above figure is clarified with subtle element in the following section.

4.5 ACS712 Interfacing

Measuring Current Using ACS712:

mVperAmp (sensitivity) = 185 // use 100 for 20A Module and 66 for 30A Module

RawValue= 0

ACS-offset = 2500

Raw Value = analog Read

Voltage = (Raw Value / 1024.0) * 5000 //value Gets in mV

Amp = ((Voltage – ACS-offset)/mVperamp (sensitivity)

Basically the Arduino measures input at the analog pin, converts it to milli volts, subtracts the offset and then finally divides it by the scale factor of the current sensor. In other words, it’s nothing more than a simple Arduino voltmeter that interprets the output of the ACS712.

 

 

 

 

 

 

 

CHAPTER 5

                      SYSTEM IMPLEMENTATION

5.1 System Simulation

Practical implementation of smart energy meter is based on 5 parts. First part is implemented to get a normal energy meter that measures current, voltage and power. second part constitutes of a GSM module that is capable of communicating with the device and third part is to detect theft (tempering alert) by using Vibration sensor and in fourth part using RTC (real time clock) we set the peak hours limit in (days, hours, month). And in fifth part based on IR sensor to calculate the mechanical rotations of meter in order to calculate unit consumed by the consumer and display it on LCD and sent user its monthly bill via GSM.

Figure 5-1 load management and theft monitoring system simulation

As the simulation shows that the load of the houses control individually .in this simulation 3 loads consider as 3 houses when consumer of house 2 and 3 exceed the set limit of power during peak hours will result in a power cutoff while on other hand house 1 power remain on at that time because it’s not violate the power company set limit. To understand the working of whole system it’s important to know working of each and every component used in the project. All the components used with their working are explained below.

5.1.1 Microcontroller

A microcontroller is just like a computer that is core, memory and programmable output peripherals. Microcontrollers are designed for embedded applications. We are using Arduino Mega in our project. Arduino Mega is the central and the most integral part of our project. We interface ACS712 and potential transformers with microcontroller. It takes reading from these sensors and calculates the amount of energy and power consumed by the load. Moreover, it also communicates with our GSM module for load management. And accelerometer sensor interface with the Arduino Mega for theft detection. Sensor alert the control room when tempering with meter occur.IR sensor also interface with Arduino Mega to calculate the energy(in units) consumed by the consumer.

                                           Figure 5-2 Arduino mega board

 

 

 

 

5.1.2 ACS712

The Allegro ACS712 provides economical and accurate solutions for AC or DC current sensing in industrial, commercial and communication systems. The device consists of an accurate low-offset linear Hall sensor circuit, which is located near the die surface. In our project we are using ACS712 to measure the load current in order to find the power.

Figure 5-3 ACS712 (Current Sensor)

 

5.1.3 Potential Transformer

The function of a potential Transformer is to measure AC voltage in electrical power systems. They are designed to scale down the high AC voltages to a level where it is compatible with the measuring equipment. We have used a regular 220V to 8V step-down transformer; 1since no current is drawn from this transformer the output of transformer is very precise and scaled down replica of the input voltage signal (220 V bigger signals). Since Vrms output of transformer is 8 volts so peak voltage will be 11.34 volts, but the graph is showing 18.3 volts, this is because both the signals have been clamped up by giving DC biasing of 2.5 volts.

Figure 5-4 potential transformer

Figure 5-5 Showing the Circuit and the Output of PT

The circuit design layout for voltage measurement. The step down voltage Transformer is used to convert input supply of 240v to 11.3 Vrms Ac
Rectifier signal using full wave rectifier. The full-wave rectifier allows unidirectional current over the entire input cycle. The result of full-wave rectification is the Dc output voltage for each half-cycle pulse input. The rectified output is then passed through the capacitor to get a smooth Dc voltage. And using voltage divider rule across the resistor we get the voltage to which we give as input to Arduino.

Figure 5-6 voltage measurement circuit

 

5.1.4 Relays

A relay is simply defined as an electromechanical switch that is actuated by an electrical signal. The current flowing in one circuit causes the opening or closing of the other. All relays have an electric coil, which is powered by AC or DC current. When the applied current or voltage crosses a certain limit, the coil operates the switch, which either closes the open contacts or opens the closed contacts. We connected 3 relays in parallel to enhance the current carrying capability of relay for the domestic loads output connection. Relays are in normally closed mode.[18] When utility wants to shut down the heavy load it will send a message to GSM module, GSM module interprets the message, communicates with Arduino, as a result Arduino change the position of relay from normally closed to normally open and consequently shutting down Heavy load. Similarly, when the utility sends the message containing instruction to close Heavy load relay the Arduino will close the Heavy load relay thus activating Heavy loads.

Figure 5-7 relay

5.1.5 LCD

LCD is the abbreviation for Liquid Crystal Display. It is an instrument that displays the data on it by using light modulating property. It is the feature of liquid crystals. It is thin and flat in layout and does not emit light; therefore most LCDs are equipped with LED back lights so that display is bright and clear.  We have used alphanumeric LCD of 16 cross 4 size and interfaced with Arduino. LCD displays the total voltage, current, power and the energy of the load and also the theft detection.

Figure 5-8 16×4 Alphanumeric LCD

 

5.1.6 GSM module

From the point of view of the consumer, it just behaves like a remote control. In this project GSM plays a vital role. It is interfaced with the Arduino Mega .When the electric utility wants to shut down the Heavy load it will send a signal containing off status to GSM module. GSM sends it to Arduino over the serial port. Message is interpreted by Arduino and it will Figure 5-9 GSM Module (SIM900)

Shut down the extra load of the home. When the load shedding time is over utility again sends a message containing on status to Bluetooth module and the whole process repeats again and consequently turning on the heavy load. And during theft detection the message sent to the control room via GSM and monthly billing also done by GSM.

5.1.7 Buzzer

A buzzer is a sounding device that is also termed as an audio signaling component. It gives beeping sound whenever energy is given to it, or is activated. It is normally used in the small circuits where an alarm or emergency sound needs to be added. Its types varies, it can be mechanical buzzer or an electromechanical. Sometimes the buzzers used are of the piezoelectric nature.       Figure 5-10 piezoelectric Buzzer The   types and selection of the types depends upon the need of the circuit and the designing of the designer. We have used a piezoelectric buzzer in the meter. It gives an audible beep when the Vibration Sensor in the energy meter senses any illegal activity. And it also buzz when the consumer exceed the set limit of power during peak hours.

5.1.8 Load Board

To simulate Load management a circuit board is made and different bulbs and lamps are installed on the board. The board contains a total of 3 lamps. Each lamp has its own switch located on the board. Out of 3 lamps 2 lamps are rated 200 watts and they represent the Critical load and heavy load. Total Critical load is 250 watts.

Figure 5-11 Load Management and theft monitoring system board

 

5.2 Software Used

Software used for the project is Ares (Proteus), Arduino IDE and MS paint. Arduino Mega was programmed using Arduino IDE which is a development environment specifically designed for Arduino boards. Its editor is based on C language. Arduino IDE is very easy to use because there are many built-in functions that are readily available. One only needs to call them in their coding. The Microsoft Paint was used to make different block diagrams that are shown in this report.

5.3 Testing & Analysis 

The accuracy of Smart Energy Meter is checked by comparing the readings that are displayed on the LCD of SEM and that are received by SMS. Smart Energy Meter is also checked by connecting and disconnecting the customer’s connection. We connected different loads 100W, 200W, and 1000W and checked its performance and also detection of tempering and allocated specific units during load shedding hours. There are 2 modes of working of meter (1) normal mode (3) load shedding mode. In Normal mode we connect the meter with normal power supply from the management centre by Using RTC in which we set the Normal Mode time. In emergency mode we alert the customer before the load shedding started by sending SMS through GSM. In Load shedding hours (Peak Hours) we will provide specific unit to the consumers.

CHAPTER 6 APPLICATION AND ADVANTAGES

6.1 Advantages of Smart Energy Meter

The advantages of smart Energy Meter (SEM) are follows

• Smart Energy Meter gives you Control over how much cash you spend because of your individual consumption base load shedding system. The more you minimize the consumption of power the less you need to pay.
• The consumer doesn’t have to pay for electricity theft and errors in the bill because SEM gives the accurate free from error billing and tempering alert via GSM.
• Using SEM Utility the Electric Utility can save around 2000kw-hr per consumer every day.
• Full time availability of electricity without any kind of backup system.
• The consumer can save around $700 yearly paid for backup system (UPS)
• Free from mismanagement

6.2 Applications of Smart Energy Meter

The Application of prepaid Energy meter is as follow

• Shopping Malls & Multiplexes
• Residential Townships
• Commercial Buildings
• Hotels
• Industries

CHAPTER 7 CONCLUSION

7.1 Conclusion

As we are developing country with increasing economy by each passing day this device has the capability to revolutionaries the Energy Meter market and will become help to country revenue by stopping the power theft and punishing the dishonest customers. This is win-win scenario for both user and the Utility Company. The consumptions base load shedding system makes the user more careful in case of power consumption.

7.2 Suggestion for improvements

The projects work very well and function as constrained by the design. Though the project works satisfactorily. It has to be improved in so many ways and then it will reach the professional standards. First of all the system must be built on a dedicated PCB especially developed for this purpose will improve the efficiency of the system and will be more reliable.

One improvement that can be made in future in smart meter is to add PLC (Power Line Communication) which is currently used for home automation. One major advantage of this would be that meter would be able to communicate to the appliances within the home that are connected to the sockets via PLC module and individually turn them on/off depending on the power availability. This would give more control of the loads over the consumer side.

REFERENCES

[1] THOMAS B.SMITH “Electricity Theft: A Comparative Analysis”Published in 2004.

[2] http://medlibrary.org/medwiki/Electricity_meter

[3] http://www.wow.com/wiki/Electricity_meter

[4] K. S. K. Weranga, D. P. Chandima, and S. P. Kumarawadu, “Smart metering for next generation energy efficiency & conservation,” in Innovative Smart Grid

[5] http://www.cccme.org.cn/products/detail-3064948.aspx

[6] http://electrical-engineering-portal.com/overview-of-single-phase-induction-typeenergy-meter

[7] Abdul H. Samra and Mario.,’’Load management implementation, a method of improving financial performance in power systems.’’ US’95 conference record of the 1995 IEEE industry application conference.

[8] http://www.electronics-tutorials.ws/transformer/current-transformer.html

[9] https://openenergymonitor.org/emon/sites/default/files/Arduino%20AC%20current %20input%20A.png

[10] Electric Utility Deregulation and Restructuring and Power Technologies (DRPT), 2011 4th International Conference on, 2011, pp. 1586-1589. 33

[11] M. Temneanu and A. S. Ardeleanu, “Hardware and software architecture of a smart meter based on electrical signature analysis,”

[12] http://163.117.157.189/wordpress/wp-content/uploads/2014/10/Arduino-ACcurrent-input-A.png

[13] www.ijaiem.org

[14] http://163.117.157.189/wordpress/?page_id=4

[15] http://www.openenergymonitor.org/emon/node/58

[16] http://en.wikipedia.org/wiki/Electricity_meter

[17] http://electronicsforu.com/resources/gsm-module

[18] http://www.sharepdf.com/59ba8e52b9ad4c8c98d961d3d0672235/new%20documentation(2)(1)(1).htm

APPENDIX A

 

 

GSM Module (SIM900):

 

 

                                   APPENDIX B

 

Pin Configuration of Arduino mega:

 

 

                                   APPENDIX C

 

LCD 16×4 Pin out Diagram:

 

 

                                   APPENDIX D

 

RTC (DS1302):