SCADA Based Power Distribution and Management System A BE Final Year Project by Fawad Shah 051-14-21413/BEEE/F14 Safeel Ahmad 051-14-21033/BEEE/F14 Supervised by Mr

SCADA Based Power Distribution and Management System

A BE Final Year Project by
Fawad Shah
051-14-21413/BEEE/F14
Safeel Ahmad
051-14-21033/BEEE/F14
Supervised by
Mr.Muntazir Hussain
Department of Electronic Engineering
& Technology IQRA University, Islamabad
Certificate of Approval
It is certified that we have checked the project presented and demonstrated by Fawad Shah 21413-/BEEE/F14, Safeel Ahmad 21033-/BEEE/F14, and approved it.

External Examiner
Internal Examiner
Supervisor
Engr. Mr.Muntazir Hussain
Department of Electronic Engineering, & Technology, IUIC

In the name of Allah (SWT), the most beneficent and the most merciful.

A BE Final Year Project submitted to the Department of Electronic Engineering IQRA University, Islamabad in partial fulfillment of the requirements for the award of the degree of Bachelor of Science in Electronic Engineering.

DECLARATION
We hereby declare that this work, neither as a whole nor as a part there of has been copied out from any source. No portion of the work presented in this report has been submitted in support of any application for any other degree or qualification of this or any other university or institute of learning. We further declare that the referred text is properly cited in the references.

Fawad Shah
051-14-22413-
/BEEE/F14
Safeel Ahmad
051-14-21033- /BEEE/F14
ACKNOWLEDGMENTS
This BS thesis in Electronics Engineering has been conducted at Department of Electronic Engineering, & Technology, IQRA University, as part of the degree program. We would like to thank Engr.Mr Muntazir Hussain for providing us an opportunity to work on this project, under his supervision and guidance throughout the project. We would also like to thank Engr. Abu baker Talha for his help, efforts and dedicated support throughout the project.
Further we are particularly thankful to almighty Allah and grateful to our parents, brothers and sisters who always supported and encouraged us during our project and studies at IUI.

Fawad Shah
Safeel Ahmad
Project Title: SCADA Based Power Distribution And Management System
Undertaken By: Fawad Shah (21413- /BEEE/F14)
Safeel Ahmad (21033-/BEEE/F14)
Supervised By:
Engr. Mr. Muntazir Hussain
Lecturer
Sup
Date Started: Date Completed:
Tools Used:
Proteus
LABVIEW
SCADA.

Multisim
Selpro (PLC)
ABSTRACT
To overcome the deficiency of electricity there is need of a system which continuously monitors demand of power or electricity and take decision based on what is important load at any time. To accomplish this city is divided into geographical areas. Each area has different types of users and hence loads demand also. As demand of power is always greater than supply so it is important to wisely distribute power in this regard there is need to switch off load when another user is at its peak time. This supervision is performed wirelessly at remote area. Status of power consumed is wirelessly transferred and also controlled wirelessly at remote area.

This is very general make to the point abstract purpose, methodology, results and application future use as had mentioned in proposal in start of FYP.

Table of Contents
CHAPTER 1
INTRODUCTION
1.1 Summary …………………………………………………………………………………………………………………………………14
1.2 SCADA System …………………………………………………………………………………………………………………………………15
1.2.1 Basic SCADA Architecture ………………………………………………………………………………………………………………………………… 16
1.2.2 System Components of SCADA ……………………………………………………………………………………………………………………………………………..16
1.3 Desighodologn Methodology ……………………………………………………………………………………………………….………………………….17
1.3.1 Geographical regions …………………………………………………………………………………………….…………………………………….17
1.4 Literature review …………………………………………………………………………………………………………………………………..18
1.4.1 How SCADA works …………………………………………………………………………………………………………………………………..19
1.4.2 Increase Up Time,Cut cost …………………………………………………………………………………………………..………………………………19
1.4.3 Implementation Consideration …………………………………………………………………………………………………….…………………………….20
1.4.4 Better Data presentation and Improved analysis ……………………………………………………………………………………………….……………………………….…21
1.4.5 Benefits of Implementing SCADA system for Electrical Distribution …………………………………………………………………………………………………………………………….…….21
CHAPTER 2
Components of the project
2.1PLC
………………………………………………….……………………………………………………………………………………………22
2.2 Block Diagram of plc. ……………………………………………………………………………………………………………………………………………….23
Chapter 3
3.1 SMPS
3.2 Advantages of SMPS
…………………………………………………………………………………………………………………………………………………
3.3 Disadvantages of SMPS ……………………………………………………………………………………………….………………………………………………..

3.4 Block diagram of SMPS ………………………………………………………………………………………………………………………………………………..

3.5 Circuit diagram of SMPS ………………………………………………………………………………………………………………………………………………..

Chapter 4
Implementation of Project
4.1 Circuit Diagram of project
…………………………………………………………………………………………………………………………………..

4.2 System Architecture of project
…………………………………………………………………………………………………………………………………..

4.3 Working of the project
………………………………………………………………………………………………………………………………….

4.4 Project Model Working steps
………………………………………………………………………………………………………………………………….

4.5 Advantages of the project
………………………………………………………………………………………………………
Chapter 5
Hardwar Implementation

Chapter 6
Software Simulation
Chapter 7
Conclusion and future work
List of Figures
List of Tables
List of Abbreviations
CHAPTER 1IntroductionSummery
The consumption of electric power has increased significantly in the past few years, and its demand is still increasing every day. In this regard, its proper distribution is a significant challenge. This project includes a method not only to improve the existing power distribution by using SCADA but also to reduce the human errors from the system by making the system automated. As a prototype for this paper, a geographical area was divided in to three regions named as region (as Industrial Sector), region (Commercial Sector), region (Residential Sector) and region (Social Sector). These four regions were used as the Remote Terminal Units RTU’s and were further divided into four sectors based on different types of consumers. One main control unit was set to handle the whole power system which was referred to as the MTU (master terminal unit). MTU was designed in such a way that not only it was capable to show RTU’s readings on Graphical user interface-GUI but also to control them. By establishing such a design, distribution of electric power based on priority was achieved among these regions and thus the load requirements were managed by means of priorities among them. The entire load management task was supervised by an individual who was authorized to control the MTU’s GUI. SCADA system enabled the MTU to regulate the electric power in regions and their sectors. All the RTU’s were connected with the MTU by means of a wireless network. If the system works accordingly, the MTU would be able to access the RTU’s. SCADA provides a platform to manage the overall system with the minimal manpower; hence, the human errors were reduced. To implement this project firstly a city whose load have to be managed should be well organized geographically. For existing cities if sub sectors for examples educational areas or industrial areas are not located near to each other they should be considered a single group or region A. In construction of new town for distribution of power following city model is feasible to this project implementation. In fig 1.1 there are two circle. Inner circle has higher priority at specified time. Outer circle has higher priority at different time.

Figure1. STYLEREF 2 s 0. SEQ Figure * ARABIC s 2 1: City mode
1.2 SCADA System
The operator Supervisory control and data acquisition (SCADA) is a system of software and hardware elements that allows industrial organizations to:
Control industrial processes locally or at remote locations
Monitor, gather, and process real-time data
Directly interact with devices such as sensors, valves, pumps, motors, and more through human-machine interface (HMI) software.

SCADA systems are crucial for industrial organizations since they help to maintain efficiency, process data for smarter decisions, and communicate system issues to help mitigate downtime. The basic SCADA architecture begins with programmable logic controllers (PLCs) or remote terminal units (RTUs). PLCs and RTUs are microcomputers that communicate with an array of objects such as factory machines, HMIs, sensors, and end devices, and then route the information from those objects to computers with SCADA software. The SCADA software processes, distributes, and displays the data, helping operators and other employees analyze the data and make important decisions.

For example, the SCADA system quickly notifies an operator that a batch of product is showing a high incidence of errors. The operator pauses the operation and views the SCADA system data via an HMI to determine the cause of the issue reviews the data and discovers that Machine 4 was malfunctioning. The SCADA system’s ability to notify the operator of an issue helps him to resolve it and prevent further loss of product.

1.2.1 Basic SCADA Architecture
Supervisory Control and Data Acquisition (SCADA) is a control system architecture that uses computers, networked data communications and graphical user interfaces for high-level process supervisory management, but uses other peripheral devices such as programmable logic controllers and discrete PID controllers to interface to the process plant or machinery. The operator interfaces which enable monitoring and the issuing of process commands, such as controller set point changes, are handled through the SCADA supervisory computer system. However, the real-time control logic or controller calculations are performed by networked modules which connect to the field sensors and actuators.

Figure1. STYLEREF 2 s 0. SEQ Figure * ARABIC s 2 1: SCADA Architecture
1.2.2 System Components of SCADA
The SCADA system mainly consists of the following subsystems:
GUI or Graphical User Interface to present data to human operator to control the process.

RTU or remote Terminal units which connects sensors and transform signals to digital data.

Microcontrollers to control all the processes within a grid station and to process data.

Terminal system, to interface controllers and RTU’s with centralized control system.

Data acquisition server is an application service which processes industrial protocols to connect application services.

Supervisory systems (computers), to collect data on processes and send commands to the SCADA system
Communication set-up is used to connect the supervisory system to the RTU’s
1.3 Design Methodology
Monitoring and control of three regions A, B C & D (RTU’s) of the geographical area are analyzed. Each of these areas are divided into four sectors named as Industrial Sector, Commercial Sector, Residential Sector and Social Sector. All of these sectors are connected to their RTU’s and these three RTU’s are further connected with MTU via wireless network. Often in SCADA systems, the RTU is located at a remote location. This distance can vary from tens of meters to thousands of kilometers based on different types of wireless connection. One of the most cost-effective ways of communicating with the RTU over long distances can be by simple ZigBee network. After establishing connection, a link is created between database and MTU which results in controlling of any RTU anywhere by sending and receiving real time data to the remote database and also the RTU’s can access that data and send acknowledgements to MTU. These three RTU’s, are controlling three regions, and their selves are further controlled by a centralized location named as MTU. On the GUI of MTU, every detail about the power, voltages and currents can be viewed and hence the load requirements can be managed and supplied to the distribution zones according to the consumers of RTU’s. All this may result in the proper distribution of electric power and also in removal of human errors by making the system automated.

1.3.3 System Components of SCADA
The SCADA system mainly consists of the following subsystems:
GUI or Graphical User Interface to present data to human operator to control the process.
RTU or remote Terminal units which connects sensors and transform signals to digital data.

Microcontrollers to control all the processes within a grid station and to process data.
Terminal system, to interface controllers and RTU’s with centralized control system.

Data acquisition server is an application service which processes industrial protocols to connect application services.
Supervisory systems (computers), to collect data on processes and send commands to the SCADA system
Communication set-up is used to connect the supervisory system to the RTU’s
1.3.1 Geographically Regions
A region is divided into four sectors named as industrial, commercial, residential and social sector, as shown in Figure 1.3. All of these four sectors have different load requirements according to the type of consumers in them.

30480009398000313372593980Residential Area
00Residential Area
186690093980Educational Area
00Educational Area

1866900123190Commercial Area
00Commercial Area
3133725123190Industrial Area
00Industrial Area
17526005651500
Figure1. STYLEREF 2 s 0. SEQ Figure * ARABIC s 2 1: Regions Distribution
1.4 Literature Review
Include 8-10 research paper references as told previously also and mention their work related to yours. See other reports and thesis online available.

Electric utilities must meet increasing demand for reliable power distribution while coping with decreasing tolerance for disruptions and outages. More than ever, utilities are squeezed to do more with less, and recognize the need to improve the efficiency of their power generation and distribution systems. Fortunately, many areas of the existing electrical distribution system can be improved through automation. Furthermore, by automating the distribution system now, utilities will be ready to meet the challenges of integrating intermittent supply sources like solar, wind and other distributed energy resources (DERs). Automating electrical distributions systems by implementing a supervisory control and data acquisition (SCADA) system is the one of the most cost-effective solutions for improving reliability, increasing utilization and cutting costs.

Some of the functions of SCADA in power distribution system are given below.

Improving power system efficiency by maintaining an acceptable range of power factor
Limiting peak power demand
Continuous monitoring and controlling of various electrical parameters in both normal and abnormal conditions
Trending and alarming to enable operators by addressing the problem spot
Historian data and viewing that from remote locations
Quick response to customer service interruptions
How SCADA Works
A SCADA system for a power distribution application is a typically a PC-based software package. Data is collected from the electrical distribution system, with most of the data originating at substations. Depending on its size and complexity, a substation will have a varying number of controllers and operator interface points.

In a typical configuration, a substation is controlled and monitored in real time by a Programmable Logic Controller (PLC) and by certain specialized devices such as circuit breakers and power monitors. Data from the PLC and the devices is then transmitted to a PC-based SCADA node located at the substation.

One or more PCs are located at various centralized control and monitoring points. The links between the substation PCs and the central station PCs are generally Ethernet-based and are implemented via the Internet, an intranet and/or some version of cloud computing. In addition to data collection, SCADA systems typically allow commands to be issued from central control and monitoring points to substations. If desired and as circumstances allow, these commands can enable full remote control.

Increase Uptime, Cut Costs
Many utilities still rely on manual labor to perform electrical distribution tasks that can be easily automated with SCADA systems. In addition to cutting labor costs, automation facilitates smoother operations while minimizing disruptions. Modern SCADA systems feature built-in redundancy and backup systems to provide sufficient reliability, and can be much faster-acting and consistent than manual processes. SCADA systems, however, do more than simply collect data. They also deliver automated control that greatly benefits utilities. Their alarms detect problems in the system, and analysis of these problems enables adjustments and corrections, often preventing an outage. In the event of an outage caused by an unforeseen event like a storm, a SCADA system’s advanced data collection capabilities help field workers quickly identify the exact location of the outage without having to wait for customer calls. Moreover, a SCADA system can significantly increase the speed of power restoration following an outage. SCADA-enabled switches and line recloses can help operators isolate the outage and open adjacent automatic switches to reroute power quickly to unaffected sections—all without the need for a line worker to visit the site to perform a lengthy visual inspection, often followed by an educated guess as to the exact nature and location of the problem.

Implementation Considerations
While a modern SCADA system provides multiple benefits in a cost-effective manner, there are factors to consider. At the substation level and at DER connection points, data must be collected and made available to the SCADA system. This is typically done by bringing all desired data points into a local controller such as a PLC. This may necessitate replacing manual monitoring devices such as gauges and meters with new power monitoring hardware compatible with the PLC. In other cases, automated devices may communicate via protocols not recognized by the PLC. For example, if a power monitoring device has a Modbus port and the PLC does not, some type of hardware protocol translation device might need to be purchased, configured and installed. In large substations, it might be necessary to convert all digital data protocols to Ethernet, and to install Ethernet switches and routers. The router would then be typically connected back to the central SCADA stations.

1.4.4 Better Data Presentation for Improved Analysis
SCADA systems provide many advantages including increased reliability, reduced costs, improved worker safety, greater customer satisfaction and improved utilization. Their alarms and real-time views into operations can prevent small problems from becoming big ones, and can also speed restoration time.

Standard protocols specifically designed for the industry such as DNP3 and IEC-60870-5-104 enable the SCADA system to collect information with the precision and accuracy required to diagnose shutdown causes and minimize downtime. This cuts time wasted on field visits, and also improves worker safety during outages and power restoration.

Modern SCADA systems provide dynamic dashboards, consolidating historical information with online data in order to provide meaningful information to decision makers. (Figure 3). These capabilities help existing operations uncover waste, and are vital for measuring and maintaining power system parameters as DERs are incorporated into the power generation mix.

1.4.5 Benefits of Implementing SCADA systems for Electrical Distribution:
Increases reliability through automation
Eliminates the need for manual data collection
Alarms and system-wide monitoring enable operators to quickly spot and address problems
Automation protects workers by enabling problem areas to be detected and addressed automatically
Operators can use powerful trending capabilities to detect future problems, provide better routine maintenance of equipment and spot areas for improvement
Historians provides the ability to view data in various ways to improve efficiency
Chapter 2
Programmable Logic Controller 2.1
In this Chapter we have discussed the basics of PLC, it’s Block Diagram and features. The PLC module of our Project is also described in brief.

Figure2. STYLEREF 2 s 0. SEQ Figure * ARABIC s 2 1: PLC
A programmable logic controller, PLC, or programmable controller is a digital Computer used for automation of typically industrial electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many machines, in many industries. PLCs are designed for multiple arrangements of digital and analog inputs and outputs, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed-up or non-volatile memory. A PLC is an example of a “hard” real-time system since output results must be produced in response to input conditions within a limited time, otherwise unintended operation will result.

2.2 Block Diagram of PLC

Fig. 2.0.2: PLC Architecture
A Programmable Controller is a specialized computer. Since it is a computer, it has all the basic component parts that any other computer has a Central Processing Unit, Memory, Input Interfacing and Output Interfacing. 8 A typical programmable controller block diagram is shown below.

2.3 The Central Processing Unit (CPU)
The central processing unit is the control portion of the PLC.

It interprets the program commands retrieved from memory and acts on those commands.

In present day PLC’s this unit is a microprocessor based system.

The CPU is housed in the processor module of modularized systems.

2.4 Memory
Memory is in the system is generally of two types: ROM and RAM.

The ROM memory contains the program information that allows the CPU to interpret and act on the Ladder Logic program stored in the RAM memory.

RAM memory is generally kept alive with an on-board battery so that ladder programming is not lost when the system power is removed.

This battery can be a standard dry cell or rechargeable nickel-cadmium type.

Newer PLC units are now available with Electrically Erasable Programmable Read Only Memory (EEPROM) which does not require a battery.

Memory is also housed in the processor module in modular systems.

2.5 Input units

The input units can be any of several different types depending on input signals expected as described:
The input section can accept discrete or analog signals of various voltage and current levels.

Present day controllers offer discrete signal inputs of both AC and DC voltages from TTL to 250 VDC and from 5 to 250 VAC.

Analog input units can accept input levels such as ±10 VDC, ±5 VDC and 4-20 ma. Current loop values.

Discrete input units present each input to the CPU as a single 1 or 0 while analog input units contain analog to digital conversion circuitry and present the input voltage to the CPU as binary number normalized to the maximum count available from the unit.

The number of bits representing the input voltage or current depends upon the resolution of the unit.

This number generally contains a defined number of magnitude bits and a sign bit.

2.6 Output units
The output unit operate much the same as the input units with the exception that the unit is either sinking (supplying a ground) or sourcing (providing a voltage) discrete voltages or sourcing analog voltage or current.

These output signals are presented as directed by the CPU. The output circuit of discrete units can be transistors for TTL and higher DC voltage or Triacs for AC voltage outputs.

For higher current applications and situations where a physical contact closure is required, mechanical relay contacts are available.

These higher currents, however, are generally limited to about 2-3 amperes.

The analog output units have internal circuitry which performs the digital to analog conversion and generates the variable voltage or current output.

2.3 Features of PLC
Compact PLC
Configurable LED display
Window based software
program for configuration
Control panel with PLC (grey elements in the center). The unit consists of separate. Elements, from left to right; power supply, controller, relay units for in- and output. The main difference from other computers is that PLCs are armored for severe. Conditions (such as dust, moisture, heat, cold), and have the facility for extensive input/output (I/O) arrangements. These connect the PLC to sensors and actuators. PLCs read limit switches, analog process variables (such as temperature and pressure), and the positions of complex positioning systems. Some use machine vision. On the actuator side, PLCs operate electric motors, pneumatic or hydraulic cylinders, magnetic relays, solenoids, or analog outputs. The input/output arrangements may be built into a simple PLC, or the PLC may have external I/O modules attached to a computer network that plugs into the PLC.

2.4 System scale of PLC
A small PLC will have a fixed number of connections built in for inputs and outputs. Typically, expansions are available if the base model has insufficient I/O. Modular PLCs have a chassis (also called a rack) into which are placed modules with different functions. The processor and selection of I/O modules are customized for the particular application. Several racks can be administered by a single processor, and may have thousands of inputs and outputs. A special high-speed serial I/O link is used so that racks can be distributed away from the processor, reducing the wiring costs for large plants.

2.5 User interface of PLC
PLCs may need to interact with people for the purpose of configuration, alarm. Reporting, or everyday control. A human-machine interface (HMI) is employed for this purpose. HMIs are also referred to as man-machine interfaces (MMIs) and graphical user interfaces (GUIs). A simple system may use buttons and lights to interact with the user. Text displays are available as well as graphical touch screens. More complex systems use programming and monitoring software installed on a computer, with the PLC connected via a communication interface.

2.6 Programming of PLC
PLC programs are typically written in a special application on a personal computer, then downloaded by a direct-connection cable or over a network to the PLC. The program is stored in the PLC either in battery-backed-up RAM or some other non-volatile flash memory. Often, a single PLC can be programmed to replace thousands of relays.

Chapter 3
SMPS switched-mode power supply
3.1 SMPS switched-mode power supply
A switched-mode power supply (SMPS) is an electronic way taken by electric current that gets changed into power using electric apparatus apparatuses that are turned on and off at high number of times, and place for storing parts such as inductor 1 or capacitors 2 to supply power when the electric apparatus is in its non-conduction state. Electric apparatus power supplies have high doing work well and are widely used in a range of electronic necessary things, including knowledge processing machines and other sensitive necessary things having need of hard to move and good at producing an effect of power supply. A switched-mode power supply is also experienced as a switch-mode power supply or switching-mode power supply. Switched-mode power supplies are classified according to the type of input and output voltages. The four major categories are:
AC to DC
DC to DC
DC to AC
AC to AC
A basic isolated AC to DC switched-mode power supply consists of:
Input rectifier and filter
Inverter consisting of switching devices such as MOSFETs
Transformer
Output rectifier and filter
Feedback and control circuit
The input DC supply from a rectifier or battery is fed to the inverter where it is turned on and off at high frequencies of between 20 KHz and 200 KHz by the switching MOSFET or power transistors. The high-frequency voltage pulses from the inverter are fed to the transformer primary winding, and the secondary AC output is rectified and smoothed to produce the required DC voltages. A feedback circuit monitors the output voltage and instructs the control circuit to adjust the duty cycle to maintain the output at the desired level.

There are different circuit configurations known as topologies, each having unique characteristics, advantages and modes of operation, which determines how the input power is transferred to the output. Most of the commonly used topologies such as fly back, push-pull, half bridge and full bridge, consist of a transformer to provide isolation, voltage scaling, and multiple output voltages. The non-isolated configurations do not have a transformer and the power conversion is provided by the inductive energy transfer.

3.2 Advantages of switched-mode power supplies:
Higher efficiency of 68% to 90%
Regulated and reliable outputs regardless of variations in input supply voltage
Small size and lighter
Flexible technology
High power density
3.3 Disadvantages of switched-mode power supplies:
Generates electromagnetic interference
Complex circuit design
Expensive compared to linear supplies
Switched-mode power supplies are used to power a wide variety of equipment such as computers, sensitive electronics, battery-operated devices and other equipment requiring high efficiency.

3.4 Block diagram of SMPS:

Fig 3.1
3.5 SMPS Circuit Diagram:

Fig 3.2 (SMPS)
3.4.6 SMPS Circuit Diagram

Fig 3.4(smps)
Chapter 4
Implementation of Project
In this Chapter we have discussed the detailed description of project including circuit
Diagram, components used and working of Project.

4.1 Circuit Diagram of Project

Fig 7.1
4.2 System Architecture of Project

Fig 7.2
In our Project we have considered a piratical area to be supplied by electrical power. This area consists of hospitals, industries, residential areas and street. The electrical power is supplied to the devices connected in an area based on their priorities. Here we have given the highest priority to the hospitals, High priority to the industries, average priority to the residential areas and the least priority to the streetlight.

4.3 Working of the Project
Energy meter measures the power generated by the power generator. Whenever less Power is generated, the lower priority devices of a specific area are cut off instead of Switching off the whole supply for the area. The power cut off is not according to area but according to the devices which have lower priorities. The switching devices connected in this area are programmed by PLC based on their priorities and monitored by SCADA. Thus according to the power generated the load shedding occurs. The power generation is done by simulation in SCADA.

Fig 7.3
4.4 Project Model Working Steps
Step1: When the energy generation is 100% and above 75% then all the areas will get power supply (all LED glows).

Step2: When the energy generation is below 75% and above 50% then the power supply will be cut off for the least priority area (LED 4 gets switched off). off for the least priority and average priority areas (LED 4 and LED 3 gets switched off).

Step 3: When the energy generation is below 50% and above 25% then the power supply will be cut off for the least priority and average priority areas (LED 4 and LED 3 gets switched off).

Step 4: When the energy generation is below25% and above 0%then the power supply will be available only for the critical or highest priority area (only LED 1 glows). Thus the power supply will always be available for the critical area until the energy generation is 0%.

4.5 Advantages of Project
No need of Human Being required for changing the load
All kinds of human errors and mistakes are minimized
No continuous attention is required for monitoring the system
No need of Site visits by Personnel for inspection
Reduced Space
Economical and Energy Saving
Greater Life and Reliability through Automation
Tremendous Flexibility
Automation protects workers by enabling problem areas to be detected and Addressed automatically
Alarms and system-wide monitoring enable operators to quickly address Problems
Historians provides the ability to view data in various ways to improve Efficiency

Chapter 4
4.1 Potential Transformer
The potential transformer may be defined as an instrument transformer used for the transformation of voltage from a higher value to the lower value. This transformer steps down the voltage to a safe limit value which can be easily measured by the ordinary low voltage instrument like a voltmeter, wattmeter and watt-hour meters, etc.

4.1.2 Construction of Potential Transformer
The potential transformer is made with high-quality core operating at low flux density so that the magnetizing current is small. The terminal of the transformer should be designed so that the variation of the voltage ratio with load is minimum and the phase shift between the input and output voltage is also minimum. The primary winding has a large number of turns, and the secondary winding has a much small number of turns. For reducing the leakage reactance, the co-axial winding is used in the potential transformer. The insulation cost is also reduced by dividing the primary winding into the sections which reduced the insulation between the layers.

4.2.3 Connection of Potential Transformer
The potential transformer is connected in parallel with the circuit. The primary windings of the potential transformer are directly connected to the power circuit whose voltage is to be measured. The secondary terminals of the potential transformer are connected to the measuring instrument like the voltmeter, wattmeter, etc. The secondary windings of the potential transformer are magnetically coupled through the magnetic circuit of the primary windings. The primary terminal of the transformer is rated for 400V to several thousand volts, and the secondary terminal is always rated for 400V. The ratio of the primary voltage to the secondary voltage is termed as transformation ratio or turn ratio.

Fig 4.1
4.3 Ratio and Phase Angle Errors of Potential Transformer
In an ideal potential transformer, the primary and the secondary voltage is exactly proportional to the primary voltage and exactly in phase opposition. But this cannot be achieved practically due to the primary and secondary voltage drops. Thus, both the primary and secondary voltage is introduced in the system.

4.3.1 Voltage Ratio Error
The voltage ratio error is expressed in regarding measured voltage, and it is given by the formula as shown below.

Where Kn is the nominal ratio, i.e., the ratio of the rated primary voltage and the rated secondary voltage.

4.3.2 Phase Angle Error
The phase angle error is the error between the secondary terminal voltage which is exactly in phase opposition with the primary terminal voltage.

The increases in the number of instruments in the relay connected to the secondary of the potential transformer will increase the errors in the potential transformers.

Burden of a Potential Transformer
The burden is the total external volt-amp load on the secondary at rated secondary voltage. The rated burden of a PT is a VA burden which must not be exceeded if the transformer is to operate with its rated accuracy. The rated burden is indicated on the nameplate. The limiting or maximum burden is the greatest VA load at which the potential transformer will operate continuously without overheating its windings beyond the permissible limits. This burden is several times greater than the rated burden.

4.5 Phasor Diagram of a Potential Transformer
The phasor diagram of the potential transformer is shown in the figure below.

Fig 4.2
Where, Is – secondary currentEs – secondary induced emfVs – secondary terminal voltageRs – secondary winding resistanceXs – secondary winding reactanceIp – Primary currentEp – primarily induced emfVp – primary terminal voltageRp – primary winding resistanceXp – primary winding reactanceKt – turn ratioIo – excitation currentIm – magnetising component of IoIw – core loss component of Io?m – main flux?- phase angle error
The main flux is taken as a reference. In instrument transformer, the primary current is the vector sum of the excitation current Io and the current equal to the reversal secondary current Is multiplied by the ratio of 1/kt. The Vp is the voltage applied to the primary terminal of the potential transformer. The voltage drops due to resistance and reactance of primary winding due to primary current is given by IpXp and IpRp. When the voltage drop subtracts from the primary voltage of the potential transformer, the primarily induced emf will appear across the terminals. This primary emf of the transformer will transform into secondary winding by mutual induction and converted into secondary induced emf Es. This emf will drop by the secondary winding resistance and reactance, and the resultant voltage will appear across the secondary terminal voltage, and it is denoted by Vs.

4.6 Applications of Potential Transformer
It is used for a metering purpose.

For the protection of the feeders.

For protecting the impedance of the generators.

For synchronizing the generators and feeders.

The potential transformers are used in the protecting relaying scheme because the potential coils of the protective device are not directly connected to the system in case of the high voltage. Therefore, it is necessary to step down the voltage and also to insulate the protective equipment from the primary circuit.

4.7 Potential Transformer Circuit Diagram

Fir 4.3
4.8 Potential Transformer Diagram
Fir 4.5
Chapter 5
5.1 Power Measurement
The electrical power can be AC power or DC power; energy meter is used for measuring power. There are various types of energy meters, which are classified as digital energy meter, electronic energy meter, watt meter, three phase energy meter, single phase energy meter, AC power measurement meter, and so on.

The AC power is given by the product of RMS voltage value across the load, RMS current across the load, and power factor of the load. This can be represented as shown in the equation below.

Now, AC power measurement can be defined as the measurement of voltage, measurement of current, and measurement of power factor.

5.2 Voltage Sensing
The first step in Power measurement is to measure load voltage using PLC and other components. As the load voltage is AC and have the peak of 310v this peak must be first reduced by step down transformer.

Fig 5.1
Output waveform of step-down transformer has both positive and negative portion. This negative portion of wave can damage the microcontroller. So, this waveform must be rectified before feeding to microcontroller.

Figure 5.2: Half wave rectifier
Output of half wave rectifier has the same positive half cycle as input but negative half cycle is clipped and peak value is less than input because of diode drop.

Chapter 6
Distribution Automation System
This chapter explains the distribution automation system Implementation. Further this chapter also discuss the Project based on distribution automation system.

6.1 Need for Automation in Power Distribution
The demand for electrical energy is ever increasing. Today over 21% (theft apart) of the total electrical energy generated in India is lost in transmission (4-6%) and distribution (15-18%). The electrical power deficit in the country is currently about 18%. Clearly, reduction in distribution losses can reduce this deficit significantly. It is possible to bring down the distribution losses to a 6-8 % level in India with the help of newer technological options (including information technology) in the electrical power distribution sector which will enable better monitoring and control.

Fig: 6.1 Basic Distribution System
6.2 Conventional Load Shedding Approach
This section is a review of load shedding techniques that have been devised over a number of years each having its own set of applications and drawbacks.

6.2.1 Breaker Interlock Load Shedding
This is the simplest method of carrying out load shedding. For this scheme, the circuit breaker interdependencies are arranged to operate based on hardwired trip signals from an intertie circuit breaker or a generator trip. This method is often used when the speed of the load shedding is critical. Even though, the execution of this scheme is fast, breaker interlock load shedding possesses a number of inherent drawbacks:
Load shedding based on worst-case scenario only one stage of load shedding almost always, more load is shed than required Modifications to the system are costly.

6.2.2 Under-Frequency Relay (81) Load Shedding
Guidelines for setting up a frequency load shedding are common to both large and small systems. The design methodology considers fixed load reduction at fixed system frequency levels. Upon reaching the frequency set point and expiration of pre-specified time delay, the frequency relay trips one or more load breakers. This cycle is repeated until the system frequency is recovered, e.g., 10% load reduction for every 0.5% frequency reduction. Since this method of load shedding can be totally independent of the system dynamics, total loss of the system is an assumed possibility. Additional drawbacks of this scheme are described below.

6.2.3 Programmable Logic Controller-Based Load Shedding
With a Programmable Logic Controller (PLC) scheme, load shedding is initiated based on the total load versus the number of generators online and/or detection of under-frequency Conditions. Each substation PLC is programmed to initiate a trip signal to the appropriate Feeder breakers to shed a preset sequence of loads. This static sequence is continued until the frequency returns to a normal, stable level.

A PLC-based load shedding scheme offers many advantages such as the use of a distributed network via the power management system, as well as an automated means of load relief. However, in such applications monitoring of the power system is limited to a portion of the network with the acquisition of scattered data. This drawback is further compounded by the implementation of pre-defined load priority tables at the PLC level that are executed sequentially to curtail blocks of load regardless of the dynamic changes in the system loading, generation, or operating configuration. The system-wide operating condition is often missing from the decision-making process resulting in insufficient or excessive load shedding. In addition, response time (time between the detection of the need for load shedding and action by the circuit breakers) during transient disturbances is often too long requiring even more load to be dropped.

6.3 Benefits of Distribution Automation System Implementation
The benefits of distribution automation system implementation can be classified in three major areas are as follows:
6.3.1 Operational ; Maintenance benefits
Improved reliability by reducing outage duration using auto restoration scheme
Improved voltage control by means of automatic VAR control
Reduced man hour and man power
Accurate and useful planning and operational data information
Better fault detection and diagnostic analysis
Better management of system and component loading
6.3.2 Financial benefits
utilization of system capacity
Customer Increased revenue due to quick restoration
Improved retention for improved quality of supply
6.3.3 Customer related benefits
Better service reliability
Reduce interruption cost for Industrial/Commercial customers
Better quality of supply
6.4 Areas of Distribution Automation System Implementation
The area distribution automation system can be divided into two areas.

6.4 Distribution Substation and Feeder Automation
Usually the distribution automation on substation and feeder are integrated to share
Common monitoring and controlling equipment and devices. Distribution substation
Automation includes supervisory control of circuit breakers, load tap changers (LTCs),
Regulators, re closers, sectionalizes, switches and substation capacitor banks. Remote data acquisition is required in order to achieve effective use of the supervisor control function.

Transformer Load Balancing
Transformer load balance monitoring provides remote access to near real-time information concerning the overall operation of the distribution system. This information can be used on a daily basis to verify the effects of other down line events such as capacitor switching, residential load control, and re-closer operations. It is also useful on a periodic basis to fine tune the efficiency of the Utility’s power distribution configuration.

6.4.2 Voltage Regulation
This feature of DAS offers utility personnel the ability to reduce line voltage during peak demand times by remotely taking control of the Load Tap Changer. It also facilitates the remotely boosting of line voltages above the local LTC settings in case of emergency situations such as back-feeding.

Fault Isolation and Sectionalizing
Before an outage from several remote monitoring of the recloser operation to the melting of a fuse link, utilities can detect the fault very fast and can take quick action to clear that fault. Even during the outage of the power supplies distribution automation devices on that line can report the data remotely. By correlating the last voltage or current measured points along the distribution system, an indication of the nature
Of the fault as well as its approximate location can be obtained.

Quality of Service (QoS) Monitoring
Quality of service is different things to different utilities. The most comprehensive definition includes monitoring power outages and its duration, the track record of power disturbances (such as voltage blinks, harmonics and voltage sags), and monitoring voltage wave-form distortions.

6.5 Advanced Distribution Automation
6.5.1 Project Objective
The objective of Advanced Distribution Automation Function is to enhance the reliability of power system service, power quality, and power system efficiency, by automating the following three processes of distribution operation control: data preparation in near-real-time; optimal decision-making; and the control of distribution operations in coordination with transmission and generation systems operations.

6.5.2 Scope of the Project
The ADA Function performs following functions.

Data gathering, along with data consistency checking and correcting
Integrity checking of the distribution power system model
Periodic and event-driven system modeling and analysis
Contingency analysis
Coordinated Volt / VAR optimization
Fault location, isolation, and service restoration
Multi-level feeder reconfiguration
Logging
These processes are performed through direct interfaces with different databases and
Systems, comprehensive near real-time simulations of operating conditions, near real-time predictive optimization, and actual real-time control of distribution operations.

6.5.3 Status of the Project
The methodology and specification of the Function for current power system conditions have been developed, and prototype (pilot) and system-wide project in several North-American utilities have been implemented by Utility Consulting International
And its client utilities prior to Grid Architecture project.

Chapter 8
Relays modules
8.1 Relay
A relay is an electromagnetic switch operated by a relatively small electric current that can turn on or off a much larger electric current. The heart of a relay is an electromagnet (a coil of wire that becomes a temporary magnet when electricity flows through it).

Figure 8.1
When power flows through the first circuit (1), it activates the electromagnet (brown), generating a magnetic field (blue) that attracts a contact (red) and activates the second circuit (2). When the power is switched off, a spring pulls the contact back up to its original position, switching the second circuit off again.

Fig 8.2 (Relay working)
The main operation of a relay comes in places where only a low-power signal can be used to control a circuit. It is also used in places where only one signal can be used to control a lot of circuits.

8.1.1 Relay Schematic
In this circuit RL1 is relay which is connected to load. RL1 has its driving circuitry in which we used the transistor and diode for maximum current controlling. We connected the relay with load in normally closed position when we put the logic then relay move from normally closed to normally open condition at this time load is disconnect with battery.

Figure 8.1.1 Relay Schematic
8.2 Energized Relay (ON)
The current flowing through the coils represented by pins 1 and 3 causes a magnetic field to be aroused. This magnetic field causes the closing of the pins 2 and 4. Thus the switch plays an important role in the relay working. As it is a part of the load circuit, it is used to control an electrical circuit that is connected to it. Thus, when the relay in energized the current flow will be through the pins 2 and 4

Figure 8.3(Normally Closed Relay)
8.3 De – Energized Relay (OFF)
As soon as the current flow stops through pins 1 and 3, the switch opens and thus the open circuit prevents the current flow through pins 2 and 4. Thus the relay becomes de-energized and thus in off position.

Figure 8.4: Normally Open Relay
In simple, when a voltage is applied to pin 1, the electromagnet activates, causing a magnetic field to be developed, which goes on to close the pins 2 and 4 causing a closed circuit. When there is no voltage on pin 1, there will be no electromagnetic force and thus no magnetic field. Thus, the switches remain open.

8.4 Normally Open Contact (NO) 
NO contact is also called a make contact. It closes the circuit when the relay is activated. It disconnects the circuit when the relay is inactive.

8.5 Normally Closed Contact (NC) 
NC contact is also known as break contact. This is opposite to the NO contact. When the relay is activated, the circuit disconnects. When the relay is deactivated, the circuit connects.

8.6 Change-over (CO) / Double-throw (DT) Contacts 
This type of contacts is used to control two types of circuits. They are used to control a NO contact and also a NC contact with a common terminal. According to their type they are called by the names break before make and make before break contacts.

Figure 8.5 Relay Types
8.7 Voltage Sensing Circuit
In this circuit, we are using Transformer to step down the voltage and then voltage divider to get the small voltage. After this we used the precision rectifier to get the rectifier voltage without any loss Rectifier output then pass through the next step to get the peak value of the voltage for PLC this is DC value of voltage.

Show theoretical calculated values also and compare with simulated waveform graph of OCR below.
Figure 8.6 Voltage Sensing Schematic
8.8 Graphical Output of Voltage Sensing Circuit
This is the output waveforms of the voltage sensing circuit. Yellow wave is the input signal after voltage divider we get the small voltage, pink wave is the output of the precision rectifier and the last one green is the peak output of the complete circuit.

Figure 8.6: Voltage Sensing Waveforms
8.9 Symbol of relay module
Fig 8.7