Power Quality Analysisof Household Appliances andSpeed Control of Three Phase Induction Motor using PLC and HMI

7/27/2019 Power Quality Analysisof Household Appliances andSpeed Control of Three Phase Induction Motor using PLC and H

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Power Quality Analysis

of Household Appliances and

Speed Control of Three Phase Induction Motor

using PLC and HMI

PROJECT REPORT

Submitted in Partial Fulfillment of the Requirements for the Award of

Degree of

Bachelor of Technology

in

Electrical Engineering

Submitted By:

Faraz Ahmad, Mohammad Saud, Mohammad Zaid

Under the Supervision of

Dr. Asfar Ali Khan

DEPARTMENT OF ELECTRICAL ENGINEERING

ZAKIR HUSAIN COLLEGE OF ENGINEERING AND TECHNOLOGY

ALIGARH MUSLIM UNIVERSITY

2013


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Authors: Faraz Ahmad, Mohammad Saud, Mohammad Zaid | 1

Power Quality Analysis

of Household Appliances and

Speed Control of Three Phase Induction

Motor usingPLC and HMI

Faraz Ahmad, Mohammad Saud, Mohammad Zaid




MAY 2013


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Certificate

This is to certify that the work contained in the thesis titled

Power Quality Analysis of Household Appliances and

Speed Control of Three Phase Induction Motor usingPLC and HMI

by Mr. Faraz Ahmad, Mr. Mohammad Saud and Mr.

Mohammad Zaid, has been carried out under my supervision

and that this work has not been submitted elsewhere for a

degree.

Dr. Asfar Ali Khan

(Assistant Professor)

Department of Electrical Engineering

Zakir Husain College of Engineering and TechnologyAligarh Muslim University


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ACKNOWLEDGEMENT

We wish to express sincere gratitude to Dr. Asfar Ali

Khan (Assistant Professor, Department of Electrical

Engineering) for his encouragement and guidance

throughout the work on this project. The invaluable

suggestions given by him have helped me to improve the

performance of my project and deliver the project in

time.

We express our heartfelt thanks to Mr. Sharique Khan

and Mr. Majid Khan (ZMS Technologies) for their

training and invaluable encouragement and support.

Mr. Shahid Karim (Siemens India Ltd) was a great

mentor and helped us in obtaining the various technical

support.

Finally yet importantly, I would like to express my

heartfelt thanks to my beloved parents for their blessings,

my friends and classmates for their help and wishes for

the successful completion of this project.

Faraz Ahmad

Mohammad Saud

Mohammad Zaid


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PREFACE TO THE PROJECT

With the rapid change in industries and information technology in recent years, some

traditional bulk electronic appliances have to be monitored for a long time. All of their control

devices such as communication interfaces gradually enter the internet information era. The

control of all equipment has been performed through the use of computers. Most equipment

use PLCs to connect with computers to monitor each load and electricity consuming devices.

Programmable Logic Controllers are widely used in industrial control because they are

inexpensive, easy to install and very flexible in applications. A PLC interacts with external

world through its inputs and outputs. Since technology for control of electric drives became

available, the use of programmable logic controllers (PLC) with power electronics in electric

machines applications has been introduced in the manufacturing automation.

This use offers advantages such as lower voltage drop when turned on and the ability to

control motors and other equipment with a virtually unity power factor. Many factories use

PLC in automation processes to diminish production cost and to increase quality and

reliability. To obtain accurate industrial electric drive systems, it is necessary to use PLC

interfaced with power converters, personal computers and other electric equipment. The

project presents a PLC-based monitoring and control system for a three phase induction

motor and power monitoring of electrical devices. It describes the design and implementation

of the configured hardware and software hardware and software. The test results obtained

on induction motor performance show improved efficiency and increased accuracy in

variable-load constant-speed controlled operation, thus, PLC correlates and controls the

operational parameters to the speed set point requested by the user and monitors during

normal operation and under trip conditions.


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INDEX

*Page numbers altered post-formatting.

SerialNo. Content Page No*1 Objective of the Project 4

2

1. Introduction

I. Power Quality AnalysisII. Programmable Logic Controllers

III. Architecture of PLCIV. Siemens PLC S7 300V. S7 300 Datasheet

VI. Automation PyramidVII. Networking in Industrial Automation

VIII. Human Machine Interface

5 to 13

5

6

7

8

9

10

1113

3 2. Analysis of Household Loads 14

4

3. Programming of PLC

I. Introduction to Totally Integrated Automation (TIA) PortalII. Steps involved in Programming PLC S7 300 using TIA

III. Programming in ladder Logic

15 to 21

15

16

19

5

4. Speed Control of Induction Motor

I. Rotor Resistance Speed ControlII. Variable Voltage Speed Control

III. Pole ChangingIV. Variable Frequency Speed ControlV. Variable Voltage Variable Frequency Speed Control

22 to 28

23

24

2526

27

6

5. Experimental Setup

I. Power Quality Analysis of Household LoadsII. Control of Three Phase Induction Motor

III. Circuit Diagram for Rotor Resistance Speed ControlIV. Network Connection of Siemens PLC S7 300 and HMI

29 to 33

29

31

32

33

7

6. Results and Program

I. Power Quality Analysis of Household LoadsII. Speed Control of Three Phase Slip Ring Induction Motorusing PLC and HMI

7. Project Report Generated from TIA

I. Screenshots of HMI

34 to 51

34

47

47

48

8 8. Conclusion 52

9 Future Work 54

10 References 55 to 56


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List of Abbreviations

a . PLC : Programmable Logic Controllerb . SCADA : Supervisory Control and Data Acquisition

c . S7 : Step Seven (7)d . HMI : Human Machine Interfacee . PQA : Power Quality Analyzerf . TIA : Totally Integrated Automationg . THD : Total Harmonic Distortion


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OBJECTIVE OF THE PROJECT

Power Quality Analysis of Household Appliances

and

Speed Control of Three Phase Induction Motor

using PLC and HMI


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Chapter 1

Introduction

PowerQualityAnalysis ProgrammableLogicControllers ArchitectureofPLC SiemensPLCS7300 S7300Datasheet AutomationPyramid NetworkinginIndustrialAutomation


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INTRODUCTION

I. Power Quality AnalysisPower quality is an issue that is becoming increasingly important to electricity consumers at

all levels of usage. Sensitive power electronic equipment and non-linear loads are widely used

in industrial, commercial and domestic applications leading to distortion in voltage and

current waveforms. With ongoing regulatory, policy and structural changes in the Indian

electricity industry, following the Electricity Act 2003, the issue of Power Quality is poised to

become a figure-of-merit amongst the competing distribution utilities. Improvement of

Power Quality has a positive impact on sustained profitability of the distribution utility on the

one hand and customer satisfaction on the other.

The analysis helps to monitor losses and also tells when to replace such appliances that are

faulty and are source of loss. As an example, analysis of an office can help a company to

monitor its consumptions and take necessary steps for energy saving.

The analyzer used in our project for the PQ analysis is Janitza Smart Meter UMG 511. This

analyzer has the following features:

Features

Over 2000 parameters.

Flicker Measurement.

Short term interruptions with fault recorder function.

Transient Measurement.

Measurement of Harmonics up to the 63rd.

Inrush current Measurement.

Continuous monitoring of the power quality e.g. EN 50160.

Ethernet gateway for subordinate measurement points.

Analysis of electrical faults for network problems.

Monitoring of the internal distribution network according to EN 61000-4-7, 4-15, 4-30

Report generator for EN 50160 analysis.

Remote control operation

The UMG 511 supports connectivity with the Ethernet backbone and integration with the

other smart devices and control modules.


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II. Programmable Logic ControllerA Programmable Logic Controller (PLC) is a microprocessor-based controller with multiple

inputs and outputs. It uses a programmable memory to store instructions and carry out

functions to control machines and processes. The PLC performs the logic functions of relays,

timers, counters and sequencers. It is a digital computer used for automation of

electromechanical processes. Before the PLC, control sequencing, and safety interlock logic

for manufacturing automobiles was accomplished using hundreds or thousands of relays, cam

timers and drum sequencers and dedicated closed-loop controllers.

Richard E Morley is considered to be the inventor of First PLC. PLC

development began in 1968 in response to a request from an UScar manufacturer (General Electric Hydramatic) The first PLC was

designated the 084 because it was Bedford Associates' eighty-

fourth project. Later it was called as MODICON. PLCs were installed

in industry in 1969.

Early PLCs were designed to replace relay logic systems. These PLCs were programmed in

ladder logic, which strongly resembles a schematic diagram of relay logic. The computer is

connected to the PLC through Ethernet, RS-232, RS-485 or RS-422cabling. 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. PLC programs are typically written in a special

application on a personal computer, and 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.

Unlike general-purpose computers, the PLC is designed for multiple inputs and output

arrangements, extended temperature ranges, immunity to electrical noise, and resistance to

vibration and impact. The PLCs have many applications in the day to day life. They are easily

programmable and they can be operated using the cables, modems etc. All the automation

processes are been done but using the PLCs, as they are more reliable.

Figure 1: Richard Morley


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III. Architecture of Programmable Logic Controller(PLC)

A PLC is a microprocessor based system. Various parts in a PLC are shown below as a block

diagram:

Figure 2: Architecture of a Programmable Logic Controller

Analog and Digital inputs and outputs are ports for interfacing external equipment with the

PLC. Networking Block is used for communication between PLC-Computer, PLC-PLC, PLC-

Smart Transducers (IP Based) and PLC-Smart Meters. Memory is used to store the program

and data for computation. It also stores events when it is a part of SCADA in memory cards

such as MMC, SD and Micro-SD.

Processor is the heart of PLC. All the computation is done is by the processor. Other important

part of a PLC is a clock that synchronizes all the actions.

Processor

AnalogInput &Output

Memory

ADC & DAC

DigitalInput &Output

Clock

Networking

Block


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IV. Siemens PLC S7 300

Figure 3: Representation of S7 300 in TIA

Input and Output Ports

Central Processing Unit

Interface/ Communication Ports

External Memory Slot


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V. Siemens S7 300 Data SheetDATA SHEET

WORK MEMORY 192KB0.6MS/1000 INSTRUCTIONS

DI-24/DO-16

AI-5/AO-2 INTEGRATED

4 PULSE OUTPUTS (2.5KHZ)

4 CHANNELS COUNTING AND MEASURING WITH 24 V

(60KHZ) INCREMENTAL ENCODERS

INTEGRATED POSITIONING FUNCTION

PROFINET INTERFACE AND 2 PORTS

PROFINET CBA PROXY

TCP/IP TRANSPORT PROTOCOL

COMBINED MPI/DP INTERFACE (MPI OR DP MASTEROR DP SLAVE)

MULTI-TIER CONFIGURATION UP TO 31 MODULES

CAPABLE OF SENDING AND RECEIVING IN DIRECT

DATA EXCHANGE

CONSTANT BUS CYCLE TIME


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VI. Automation PyramidAll the devices in a modern automation system are arranged in a pyramid structure as shown

below. This is usually referred to as Automation Pyramid. This pyramid shows a hierarchy of

the communication of network elements.

Figure 4: Automation Pyramid

The various layers according to the automation pyramid are:

1. The Process/ Field layer consists of sensors, valves, actuators and servo motors. It isthe basic layer where the process is implemented. All the elements in this layer either

act or provide feedback for a given command. The command is provided by the

Control Layer.

2. The Control Layer consists of PLCs. These PLCs are programmed to command the FieldLayer to perform the specified task. They are further monitored and controlled by the

SCADA layer.

3. The SCADA layer is the management layer and it does all the supervisory functions.This layer keeps a track of all the activities in real time and controls all the processes

connected to it.

4. Strategic Data Exchange layer is the enterprise layer and ERPs are executed at thislevel. This is the highest level in the automation pyramid where all the SCADA layers

merge to give a central control.


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VII. Networking in Industrial AutomationThe various layers in the automation pyramid interact with each other by the communication

interfaces such as Ethernet, Fast Ethernet. The industrial communication network is based on

Profinet, Profibus, Optical Fibers, etc.

a. Ethernet:Ethernet is a family of computer networking technologies for local area networks (LANs).

Ethernet was commercially introduced in 1980 and standardized in 1985 as IEEE 802.3.

Ethernet has largely replaced competing wired LAN technologies. The Ethernet standards

comprise several wiring and signaling variants of the OSI physical layer in use with

Ethernet. The original 10BASE5 Ethernet used coaxial cable as a shared medium. Later the

coaxial cables were replaced by twisted pair and fiber optic links in conjunction with hubs

or switches. Data rates were periodically increased from the original 10 megabits per

second to 100 gigabits per second.

Systems communicating over Ethernet divide a stream of data into shorter pieces called

frames. Each frame contains source and destination addresses and error-checking data so

that damaged data can be detected and re-transmitted. As per the OSI model Ethernet

provides services up to and including the data link layer. Since

its commercial release, Ethernet has retained a good degree of

compatibility.

b. Fast Ethernet:In computer networking, Fast Ethernet is a collective term for

a number of Ethernet standards that carry traffic at the

nominal rate of 100 Mbit/s, against the original Ethernet speed

of 10 Mbit/s. Of the Fast Ethernet standards 100BASE-TX is by far the most common and

is supported by the vast majority of Ethernet hardware currently produced. Fast Ethernet

was introduced in 1995 and remained the fastest version of Ethernet for three years

before being superseded by gigabit Ethernet. Fast Ethernet is an extension of the existing

Ethernet standard.

c. Profibus:PROFIBUS (Process Field Bus) is a standard for field bus

communication in automation technology and was first promoted in

1989 by BMBF (German department of education and research) and

then used by Siemens. It should not be confused with the PROFINET

Figure 5: Ethernet connector RJ45

Figure 6: Profibus Adapter


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standard for industrial Ethernet. The figure alongside shows a Profibus Adapter.

PROFIBUS is not an openly published and royalty-free protocol as MODBUS. PROFIBUS

was defined in 1991/1993 in DIN 19245, was then included in EN 50170 in 1996 and, since

1999, established in IEC 61158/IEC 61784. There are two variations of PROFIBUS in use

today; the most commonly used PROFIBUS DP, and the lesser used, application specific,

PROFIBUS PA:

1. PROFIBUS DP (Decentralized Peripherals) is used to operate sensors and actuators viaa centralized controller in production (factory) automation applications. The many

standard diagnostic options, in particular, are focused on here.

2. PROFIBUS PA (Process Automation) is used to monitor measuring equipment via aprocess control system in process automation applications. This variant is designed for

use in explosion/hazardous areas (Ex-zone 0 and 1). The Physical Layer (i.e. the cable)conforms to IEC 61158-2, which allows power to be delivered over the bus to field

instruments, while limiting current flows so that explosive conditions are not created,

even if a malfunction occurs. PA has a data transmission rate of 31.25 Kbit/s. However,

PA uses the same protocol as DP, and can be linked to a DP network using a coupler

device.

d. Profinet:PROFINET is the open industrial Ethernet standard of PROFIBUS & PROFINET International

(PI) for automation. PROFINET uses TCP/IP and IT standards, and is, in effect, real-time

Ethernet. The PROFINET concept features a modular structure so that users can select the

cascading functions themselves. They differ essentially because of the type of data

exchange to fulfil the partly very high requirements of speed. In conjunction with

PROFINET, the two perspectives PROFINET CBA and PROFINET IO exist. PROFINET CBA is

suitable for the component-based communication via TCP/IP and PROFINET IO used for

the real-time communication with real-time requirements in modular systems

engineering. Both communication options can be used in parallel.

PROFINET IO was developed for real time (RT) and isochronous real time (IRT)

communication with the decentralized periphery. The designations RT and IRT merely

describe the real-time properties for the communication within PROFINET IO. PROFINET

CBA and PROFINET IO can communicate at the same time on the same bus system. They

can be operated separately or combined so that a PROFINET IO subsystem appears as a

PROFINET CBA system from a system perspective.


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VIII.Human Machine Interface

Figure 7: Siemens HMI TP 117B

Human-machine interface is the part of the machine that handles the Human-machine

interaction. Membrane Switches, Rubber Keypads and Touchscreens are examples of that

part of the Human Machine Interface which we can see and touch. The HMI used is a Touch

Panel TP 117 B. It is a 6 touch screen. The HMI is used to monitor and control the inputs of

PLC and other devices connected to the HMI.

The HMI has an operating system installed on it. TP 117B uses Windows as the operating

system. Program is built and burned through TIA or WinCC Flexible software. The Tags are

kept same so that both PLC and HMI can use same inputs, outputs and memories.


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Chapter 2

Analysis of Household

Loads


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ANALYSIS OF HOUSEHOLD

LOADSThe analysis of common household Loads have been carried out. A three phase motor has

also been analyzed. The list of the analyzed loads is as follows:

a. Tube Lightb. Compact Florescent Lamps (CFL)c. Fand. Three Phase Induction Motor

The following parameters have been analyzed:

TubeLightPower

Current

CFLCFL Vs. CFL

CFL Vs. IncandascentLamp

Fan

THD by Fan

With Resistive Regulator

With Triac Regulator

VI analysis for TriacRegulator

InductionMotor

Power

THD

Voltage-Current

Power

Quality

Analysis


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Chapter 3

Programming of PLC

IntroductiontoTotallyIntegratedAutomation(TIA)Portal StepsinvolvedinProgrammingPLCS7300usingTIAProgramminginLadderLogic


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II. Steps Involved in Programming Siemens PLCS7300 using TIA

Step 1: Open TIA Software.

Figure 8: Totally Integrated Automation (TIA V11) startup window.

Step 2: Create a new Project.

Figure 9: Create a NEW Project


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Figure 10: Project Options

Step 3: Add device(s) from Devices and Network Tab

Figure 11: Add device(s)


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III. Programming in Ladder LogicLadder logic is the simplest relay logic programing language. Ladder logic is a programming

language that represents a program by a graphical diagram based on the circuit diagrams of

relay logic hardware. It is primarily used to develop software for programmable logic

controllers (PLCs) used in industrial control applications. The name is based on the

observation that programs in this language resemble ladders, with two vertical rails and a

series of horizontal rungs between them.

Ladder logic uses simple logic of opening or closing of switches (or relays). Some of the

functions are:

a. Normally Open: Represented as --| |--b. Normally Close: Represented as --|/|--c. Load: Represented as( )d. Timer ONe. Timer OFFf. Count UPg. Count DOWNh. Compare

[* Explain Ladder Logic]

A program in ladder logic looks like this:

Figure 14: AND Gate Simulated in Ladder Logic using TIA


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Tag_1 and Tag_2 are Inputs and Tag_3 is the output. The above program is a representation

of an AND gate.

The NO (Normally Open) contacts are closed when switched on and remain normally opened

when switched off. During closed condition, it allows the flow of current and during off

condition it provides infinite resistance to the current flow (ideally). The NC (Normally Closed)

contacts are opened when turned on and remains closed when turned off. At the ON state it

provides infinite resistance to current flow (ideally) and acts as short circuit otherwise.

Another program for a simple coffee dispensing machine simulated in LD Micro is shown

below:

Figure 15: Ladder Logic Program of a Coffee Dispensing Machine


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This coffee dispensing machine has three options:

- Tea- Coffee- Lemon Tea

The machine has three dispensers to mix the pre-mix coffee ingredient with hot water and

pour the mixture in a glass. This process is carried out as follows:

- The power of the machine is switched ON The required drink (Tea/ Coffee/ LemonTea) The response is stored in a memory (internal relay RT/ RC/ RLT ) The

memory is recalled and the corresponding motor is switched ON after checking that

all fuses are intact and there is no fault The mixture is poured by the Dispenser

(YDispenser).

- The fuses (FuseT/ FuseC/ FuseLT) are for protection and blow in case of a fault.


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SPEED CONTROL OF

INDUCTION MOTORAn induction motor is an asynchronous motor. This is a type of alternating current motor

where power is supplied to the rotor by means of electromagnetic induction. Such electric

motors operate because of a magnetic force (rotational torque) that is produced between the

stationary electromagnet called the stator and a rotating part called as a rotor. The three

induction motor rotates because of magnetic force exerted between a motionlesselectromagnet called the stator and a rotating electromagnet called the rotor. The motor is

either a slip ring type or a squirrel cage type. The squirrel cage type of motor runs at a constant

speed. Wound rotor or slip ring induction motor is of particular interest as we can have an

easy control over its speed.

Figure 16: Three Phase Induction Motor

Following methods are often used for the speed control of a Three Phase Induction Motor:

a. Rotor Resistance Speed Controlb. Variable Voltage Speed Controlc. Pole Changingd. Variable Frequency Speed Controle. Variable Voltage Variable Frequency (VVVF or V/F Control)


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I. Rotor Resistance Speed ControlThis is a conventional method of speed control of a three phase slip ring Induction Motor. This

involves stepping of resistance to change the effective rotor resistance and hence, change the

speed of motor. The advantage of using this control is that it is easy to implement. There are

few demerits of this control as well. Primarily, there is a constant power loss in the resistors.

Secondly, this is only possible for slip ring induction motors and not for squirrel cage type

induction motors.

Figure 17: Rotor Resistance Speed Control

Note that while the maximum torque and synchronous speed remain constant, the slip at

which maximum torque occurs increases with increase in rotor resistance, and so does the

starting torque. Whether the load is of constant torque type or fan-type, it is evident that the

speed control range is more with this method. Further, rotor resistance control could also be

used as a means of generating high starting torque. For all its advantages, the scheme has

two serious drawbacks. Firstly, in order to vary the rotor resistance, it is necessary to connect

external variable resistors (winding resistance itself cannot be changed). This, therefore

necessitates a slip-ring machine, since only in that case rotor terminals are available outside.

For cage rotor machines, there are no rotor terminals. Secondly, the method is not very

efficient since the additional resistance and operation at high slips entails dissipation.


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II. Variable Voltage Speed ControlIf the stator supply frequency is held at the rated value, the stator voltage cannot be increased

above the rated value Vs. but it can only be reduced. The torque equation tells that the

magnitude of torque is proportional to voltage squared. The shape of the torque-speed curve

will be independent of voltage. Torque speed curves for an induction motor with a variable

voltage supply are sketched in the figure below:

Figure 18: Characteristics for Variable Voltage Speed Control

The torque speed curves for a drive with a variable voltage supply do not obviously indicate

how a variable voltage supply system may provide speed control. In order to use this approach

for speed control, it is important to realize that the speed of an induction motor is dependent

of the mechanical load: steady state operation is reached when motor torque equals load

torque.

Variable voltage control can be easily achieved in practice by chopping the input sine wave,

using anti-parallel Thyristor, or triacs in low power applications. As a result, the control is

cheap, but introduces significant harmonic content into the supply and motor circuit,

reducing efficiency and power factor.


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Figure 21: Characteristics of Variable Voltage Variable Frequency


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rem P id0004|id0000|programmingbase.DigitalOut|375:119:111:46*3*rem C id0001:result|id0002:inrem C id0001:result|id0003:inrem C id0001:result|id0004:in

jsv_001f = _REALTIME / 500000AUTOSAVE(jsv_001c, 0)=jsv_001cAUTOSAVE(jsv_001e, 0)=jsv_001eAUTOSAVE(jsv_001d, 0)=jsv_001d

sub lbl_0005lbl_0004:

wait(MSYNC)jsv_0020 = _REALTIME / 500000 - jsv_001f

jsv_001f = _REALTIME / 500000jsv_001b =

= jsv_001bjsv_001c = jsv_001b

= jsv_001bjsv_001e = jsv_001b = jsv_001bjsv_001d = jsv_001b

goto lbl_0004endsub

gosub lbl_0005

The image below is the program written in graphic mode which is simpler but not all parameters can

be toggled here.

Figure 23: Program for Power Quality Analyzer


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II. Control of Three Phase Induction MotorThe experiment is conducted in the SCADA and Industrial Automation Lab, Department of

Electrical Engineering, Aligarh Muslim University. The setup includes the following devices

and equipment:

a. Siemens PLC S7 300 Kit including:a. Digital Input-Output Interface Boardb. Analog Input-Output Interface Boardc. Power Supply (230 V, 50 Hz AC Supply)d. Communication Interface (RS 232)e.

Human Machine Interface (HMI)

b. Three Phase Slip Ring Induction Motorc. Three Phase Rated Supplyd. Relayse. Contactors

Figure 24: Siemens PLC S7 300 Kit with HMI


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III. Circuit Diagram for Rotor Resistance Speed Control

The figure above shows the circuit diagram that is being implemented to control the speed of

3 Slip Ring Induction Motor. The Contactors are used to reverse the direction of the motor.

For this purpose, the phase sequence of supply fed to the motor is reversed.

Speed control is achieved by rotor resistance variation. This variation takes place in steps as

the relays RELAY 1, RELAY 2 and RELAY 3 switch the external resistances connected in series

with the rotor windings.

The above circuit is simulated in HMI and interfaced with the PLC. The digital outputs of the

PLC can later be interfaced with the Relays and Contactors to control the Motor.

The Digital Input used are:

- I 0.4 : Forward Direction Motor ON- I 0.5 : Reverse Direction Motor OFF- I 0.1, I0.2, I 0.3 : Speed Control in Step 1, 2, 3.

Relay 1

Relay 2

Relay 3

R1

R2

R3

3 Slip Ring Induction Motor

Contactor 1

Normally Closed

Contactor 2

Normally Open

R

Y

B

Figure 25: Experimental Setup for Rotor Resistance Speed Control Scheme


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IV. Network Connection of PLC S7 300 and HMI

Figure 26: Network Connection for PLC, PQA and HMI over Ethernet

The above connection diagram is the communication network diagram for the devices to

communicate among each other. The HMI and PLC have same tags for same output and input

functions. This creates a synchronism in the operation, and only required inputs and outputs

are connected.

All the devices are based on IP Addressing and are configured on Class 3 with IPs starting from

192.168.0.xxx where xxx is the address of the Computers such that all the devices come

under same subnet.

Co

mputerS

ystem

(

192.168.0

.xxx) PLC S7 300

(192.168.0.1)

HMI Touch TP 117B(192.168.0.2)

Janitza UMG 511(192.168.0.111)


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Discussion:

The current in a florescent tube light is more at the beginning, nearly twice the rated curren

spike in the above graph. This is due to the presence of a series inductor known as Choke. A

draws rated current.


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Discussion:

The active Power in a florescent tube light is less at the beginning and then as the tube starts

rated power.


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Triac Controlled (Maximum Firing AngleMinimum Voltage)

Figure 27: Maximum Firing Angle

X Axis: Time in Seconds

Y Axis: Voltage in Blue. Current in Red

Triac Controlled (Minimum Firing AngleMaximum Voltage)

Figure 28: Minimum Firing Angle

X Axis: Time in Seconds

Y Axis: Voltage in Blue. Current in Red


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b) Compact Florescent Lamp:These days the use of CFL is increasing on account to its higher efficiency, compact design

and low maintenance. But they have a severe drawback, they are major source of

harmonics in supply. This creates grave problems as heating up of insulation of cables,

noise in transformers, etc. Thus, it is necessary to know how much distortion a power

electronic circuit is causing in the supply. Total Harmonic Distortion (THD) is a measure of

how much a wave is distorted from a pure sinusoidal wave.

The presence of high THD can be known if occasionally some unexplained occurrences

such as flickering of lights, alarms going off, or MCBs, MCCBs and Earth Leakage devices

tripping for no apparent reasons are experienced. Other signs are cables running hot,hot switchboards or overheating motors. Further, the wear and tear of bearings and

insulation in motors is a strong indication of the presence of harmonics.

Some of the common and unpredictable effects of excessive harmonic include:

Overheating and sustained damage to bearings, laminations and winding insulationon generators, transformers and induction motors causing early life failure, which

could potentially result in fire.

Overheating of the stator and rotor of fixed speed electric motors; risk of bearingcollapse due to hot rotors. Overheating of cables and additional risk of failure due to resonance. Harmonics

also decrease the ability to carry rated current due to 'skin effect', which reduces a

cables effective cross sectional area.

Disruption in the operation of Uninterruptible Power Supplies (UPS). Spurious tripping or failure of sensitive electronic and computer equipment,

measurement and protection relays.

Voltage resonances leading to transient overvoltage and overcurrent failures in theelectrical network.

Electromagnetic interference (EMI) resulting in disruption to communicationequipment. Malfunction of circuit breakers and fuses.

There are various companies that manufacture CFLs. Here an analysis is done between

Crompton and Greaves and Oreva CFLs. Further, a comparison between an

incandescent lamps and a CFL is done.


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The red plot is of CFL. The above graph shows that incandescent lamps has THD less than

CFL but as its efficacy is less than that of CFL for same power consumption, CFL is preferred

over Incandescent lamps.

But in some industries the generated THD is a source of serious problems like heating and

deterioration of insulation which reduce the life of equipment.

Following is a graph for active power consumption. This graph tells primarily that the

actual power consumed is more than rated (Incandescent lamp: 100W, CFL: 18W)

Figure 31: Active Power Consumption by Incandescent Lamp and CFL

Further, it is to be noted that the power consumed by the incandescent lamps varies

exponentially (nearly quadratic curve) as the voltage is increased. Also, initially there is a

spike for the incandescent lamps. This is because at the time of start, the resistance of

filament is high therefore more current flows and hence more power is consumed. But as

it gets hotter and resistance increases, the power loss decreases for the same magnitude

of voltage.


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Following is the graph of the reactive power consumed by CFL and Incandescent lamps.

Figure 32: Reactive Power Consumption by Incandescent Lamp and CFL

The incandescent lamps filament acts as an inductor and consumes inductive power at

the time of start. The red plot shows the same. On the other hand, the CFL consumes

capacitive power due to the capacitor present in its circuit. As the firing angle is decreased

i.e. the voltage is increased, there is an appreciable drop in the reactive power

consumption but rise in active power. But the reactive power, like wise active power,

remains nearly constant for the CFL.


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c) Fan:Fan used in houses is a single phase squirrel cage induction motor. It runs at rated supply

voltage of 230V and usually consumes 40W to 150W power. The speed regulation of fan

is a very important aspect. Resistive speed regulators consume more power as a

considerable amount of heat is lost in resistance. Further, it is also bulky and needs a

bigger space on the switch board.

On the other hand, triac controlled speed regulator have higher efficiency and are small

in size. Although, they have a problem of higher THD as compared to the resistive speed

controllers. This problem is cleared by the use of filters in the triac circuits.

The graph below shows the Voltage (Blue) and Current (Red) waveforms for maximum

firing angle () i.e. minimum voltage.

Figure 33: V-I Waveform for Maximum Firing angle

Here the waveform is highly distorted and will have maximum THD.

The graph below shows the Voltage (Blue) and Current (Red) waveforms for minimum

firing angle () i.e. maximum voltage.


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Figure 34: V-I Waveform for Minimum Firing angle

Here the waveform is least distorted and will have lesser THD. The filter present in the

regulator suppresses the effect of harmonics.

The following graph represents the THD from a resistive speed controller. It is to be

noted that the THD is nearly zero at steady state (after switching).

Figure 35: THD generated by a Resistive Speed Regulator plotted against time


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The following graph shows the THD for a triac controlled speed regulator. As the firing

angle () is decreased, the THD decreases and finally reduces to zero at minimum firing

angle ().

Figure 36: THD generated by a Triac Controlled Speed Regulator plotted against time


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d) Three Phase Induction Motor:The induction motor used here is a 3 phase, 4 pole induction motor. The waveform as

obtained by the PQ analyzer for Voltage and Current is shown below.

Figure 37: V-I Waveform of Three Phase Induction Motor

The above graph clearly shows that the motor is inductive as the current waveform (Red) lags

the voltage waveform (Blue) by approximately 90o.

The graph below shows the reactive and active power consumption:

Figure 38: Active Power Consumption (1: Red, 2: Black, 3: Blue)


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II. Speed Control of Three Phase Slip Ring InductionMotor using PLC and HMI

The setup is a rotor resistance speed control scheme for slip ring induction motor. The process

flow is given below:

a. Motor will run as the Forward Mode button is pushed.b. This will switch on the Forward contactor with phase sequence: RYB.c. Speed 1 to 3 is achieved by closing of relays 1, 2 and 3.d. Motor will run in opposite direction as the Reverse Mode button is closed.e. This will switch on the Reverse contractor.f. Speed 1 to 3 is achieved by closing of relays 1, 2 and 3.g. The motor will not run if the above mentioned flow is disturbed or both Forward

and Reverse Mode buttons are pressed together.

The PLC and HMI both are programmed using TIA but the HMI can also be programmed using

WinCC Flexible. The tags used in PLC and HMI are same so that each corresponds to the

same function. The input from PLC and HMI are stored in memory tags which can be

frequently changed by toggling the switch from HMI as well as the PLC Digital Inputs.

Figure 41: Control Panel on HMI

The program in ladder logic is attached as a project report generated by TIA along with the

tag table.


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Chapter 7

Project Report Generated

by TIA


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AttachedSeparetly.


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Figure 43: Introduction and Objective


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Figure 44: About Us


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Figure 45: Control Panel to Control the Induction Motor


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Chapter 8

Conclusion


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CONCLUSION

The following conclusions were derived from the work carried in the project titled, Power

Quality Analysis of House Hold Appliances and Speed Control of Three Phase Induction Motor

using PLC and HMI.

a. Power Quality Analysis of Household Loads:i. The Power Quality Analysis of common household loads such as Incandescent

Lamps, CFLs and Fan were carried out. The analysis showed that the power

consumed by these loads were more than the rated and as specified by the

manufacturers.

ii. The CFLs produced more THD as compared to the incandescent lamps (whichproduced nearly zero THD).

iii. Two CFLs were compared for THDs. One of them that had filter installed(Crompton and Greaves CFL) produced less THD and the other (Oreva CFL)

produced more THD.

iv. Analysis of active and reactive power consumption revealed that the CFLs canoperate at voltages as low as 100V and consume rated power. The

incandescent lamps, on the other hand, consume power depending upon the

supply voltage (as P=V2/R).

v. It was also observed that at cold/ switch ON time the incandescent lampallowed a very high current to flow for a very short duration. The reason was

found to be the resistance at cold condition is very low as compared to the

resistance when it is glowing. (P=V2/R, at start condition R is less therefore, P

is high)

vi. A fan was connected initially to a resistive speed regulator and then to a traiccontrolled speed regulator. The waveform were analyzed for the current at

maximum firing angle and minimum firing angle. It was observed that at

maximum firing angle the THD was least and at minimum firing angle, THD was

maximum.


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vii. Analysis of a three phase induction motor was also carried out where thephases 1 and 3 were found healthier than phase 2. Phase 2 consumed

maximum power but generated least THD.

b. Speed Control of Three Phase Induction Motor:i. The PLC (S7 300) was programmed for the speed control of motor using rotor

resistance control scheme.

ii. The HMI was programmed and interfaced with PLC. The inputs were soprogrammed that they can be toggled from the digital input panel on PLC and

the HMI touch screen as well.


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FUTURE WORK

The project titled, Power Quality Analysis of House Hold Appliances and Speed Control of

Three Phase Induction Motor using PLC and HMI, can be further worked upon in the

following directions:

a. The Power Quality Analyzer can be interfaced with PLC S7 300 and HMI to obtain acomplete solution for control of Household Appliance by implementing SCADA and

ERP.

The measured parameters from PQAs will act as a controlling parameters for the PLCs

to run/ stop a process. As an example, an occupancy sensor based healthy power

control module can be built over PLC and PQA where only good Quality Power (power

quality parameters will be measured by PQA) will be switched ON only when there is

occupancy (Detected by sensors connected to PLC) inside the room.

b. The PLCs and PQAs can be interconnected via Industrial Ethernet Backbone and acomplete Automation Pyramid can be modelled. The setup will include ERP and SCADA

layer as well. The backbone will consist of Ethernet, Profinet, Profibus and Optical

Fiber communication protocols.

c. The HMI can be used to run SCADA using WinCC Flexible. The touch screen modulewill be used to display and control the various processes in real time. It will also keep

a track on the generated alarms and events.


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REFERENCES

[1] Electrical Machinery Fundamentals, Stephen J. Chapman, 4th Edition, 2005.[2] Electrical Machinery, A. E. Fitzgerald, 6th Edition, 2003.[3] Fundamentals of Electric Drives, G. K. Dubey, 2nd Edition, 2001.[4] PLC Programming for Industrial Automation, Kevin Collins, Chapter 1, page 5.[5] Application Layer protocol for decentralized periphery and distributed automation,

Specification for PROFINET, Version 2.3, October 2010, Order No.: 2.722, PROFIBUS

Nutzerorganisation e.V. (PNO)[6] Industrial communication with PROFINET, Manfred Popp, Order no.: 4.182,

PROFIBUS Nutzerorganisation e.V. (PNO)

[7] Ethernet: the Definitive Guide, Charles E. Spurgeon, O'Reilly Media. p. 156. ISBN978-1-56592-660-8(2000).

[8] Switched, Fast, and Gigabit Ethernet, Robert Breyer and Sean Riley, MacmillanTechnical Publishing. p. 107(1999).

[9] "The Ethernet: A Local Area Network", Digital Equipment Corporation, IntelCorporation, Xerox Corporation ACM SIGCOMM Computer Communication Review

(1980) Version 1.0 of the DIX specification.

[10] "Ethernet", Internetworking Technology Handbook. Cisco Systems. Retrieved April11, 2011.

[11] The Second Information Revolution, Gerald W. Brock, Harvard University Press. p.151. ISBN 0-674-01178-3. (2003).

[12] SIMATIC S7-300 CPU 31xC and CPU 31x: Installation and Operating Instructions,Manual on S7 300, Siemens.

[13] SIMATIC PCS 7 Evolution, Presentation by Tobias Koziol, Siemens AG, Germany.[14] PLC Programming for Industrial Automation, Instruction Set, Kevin Collins.[15] SIMATIC Programming with STEP 7 Lite V3.0, Siemens.[16] Speed Control of Induction Motor, Prof. Krishna Vasudevan, Prof. G. Sridhara Rao,

Prof. P. Sasidhara Rao, Chapter 8, NPTEL, IIT Madras, India.

[17] SIMOVERT MASTER DRIVES Operating Instructions Part II, Siemens.


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[18] Technical Support:a. Siemens India, Indiab. ZMS Technology, Germany

[19] Software Used:a. Grid Vis, Janitzab. LD Micro, Open Source, Jonathan Westhues.c. Totally Integrated Automation, Siemens.d. WinCC Flexible 2008, Siemens.

ListofFigures:Figure 1: Richard Morley .......................................................................................................... 10

Figure 2: Architecture of a Programmable Logic Controller .................................................... 11

Figure 3: Representation of S7 300 in TIA ............................................................................... 12

Figure 4: Automation Pyramid ................................................................................................. 14

Figure 5: Ethernet connector RJ45 .......................................................................................... 15

Figure 6: Profibus Adapter ....................................................................................................... 15

Figure 7: Siemens HMI TP 117B ............................................................................................... 17

Figure 8: Totally Integrated Automation (TIA V11) startup window. ................................... 22

Figure 9: Create a NEW Project ............................................................................................... 22

Figure 10: Project Options ....................................................................................................... 23

Figure 11: Add device(s) ........................................................................................................... 23

Figure 12: Select Appropriate CPU (CPU 314 C-2 PN/DP in our case) ..................................... 24

Figure 13: Main Console (GUI) for programming PLC (S7 300) ............................................... 24

Figure 14: AND Gate Simulated in Ladder Logic using TIA .................................................... 25

Figure 15: Ladder Logic Program of a Coffee Dispensing Machine ......................................... 26

Figure 16: Three Phase Induction Motor ................................................................................. 29Figure 17: Rotor Resistance Speed Control ............................................................................. 30

Figure 18: Characteristics for Variable Voltage Speed Control ............................................... 31

Figure 19: Pole changing from initial (a) to final (b) ................................................................ 32

Figure 20: Characteristic for Variable Frequency Speed Control ............................................ 33

Figure 21: Characteristics of Variable Voltage Variable Frequency ........................................ 35

Figure 22: Experimental Setup for Power Quality Analyzer .................................................... 37

Figure 23: Program for Power Quality Analyzer ...................................................................... 38

Figure 24: Siemens PLC S7 300 Kit with HMI ........................................................................... 39Figure 25: Experimental Setup for Rotor Resistance Speed Control Scheme ......................... 40
http://f/Projects/SCADA/thesis.docx%23_Toc368329468http://f/Projects/SCADA/thesis.docx%23_Toc368329468http://f/Projects/SCADA/thesis.docx%23_Toc368329472http://f/Projects/SCADA/thesis.docx%23_Toc368329472http://f/Projects/SCADA/thesis.docx%23_Toc368329473http://f/Projects/SCADA/thesis.docx%23_Toc368329473http://f/Projects/SCADA/thesis.docx%23_Toc368329492http://f/Projects/SCADA/thesis.docx%23_Toc368329492http://f/Projects/SCADA/thesis.docx%23_Toc368329492http://f/Projects/SCADA/thesis.docx%23_Toc368329473http://f/Projects/SCADA/thesis.docx%23_Toc368329472http://f/Projects/SCADA/thesis.docx%23_Toc368329468


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Figure 26: Network Connection for PLC, PQA and HMI over Ethernet ................................... 41

Figure 27: Maximum Firing Angle ............................................................................................ 46

Figure 28: Minimum Firing Angle ............................................................................................. 46

Figure 29: THD in CFL (C&G vs. Oreva) plotted vs. time .......................................................... 48

Figure 30: THD in Incandescent Lamp vs. CFL plotted vs. time ............................................... 48

Figure 31: Active Power Consumption by Incandescent Lamp and CFL .................................. 49

Figure 32: Reactive Power Consumption by Incandescent Lamp and CFL .............................. 50

Figure 33: V-I Waveform for Maximum Firing angle ............................................................... 51

Figure 34: V-I Waveform for Minimum Firing angle ................................................................ 52

Figure 35: THD generated by a Resistive Speed Regulator plotted against time .................... 52

Figure 36: THD generated by a Triac Controlled Speed Regulator plotted against time ........ 53

Figure 37: V-I Waveform of Three Phase Induction Motor ..................................................... 54

Figure 38: Active Power Consumption (1: Red, 2: Black, 3: Blue) ..................................... 54

Figure 39: Reactive Power Consumption (1: Red, 2: Green, 3: Blue) ................................ 55

Figure 40: THD generated by Induction Motor (1: Red, 2: Green, 3: Blue) ....................... 55

Figure 41: Control Panel on HMI.............................................................................................. 56

Figure 42: Root Screen ............................................................................................................. 59

Figure 43: Introduction and Objective ..................................................................................... 60

Figure 44: About Us ................................................................................................................. 61

Figure 45: Control Panel to Control the Induction Motor ....................................................... 62

Documents

Power Quality Analysisof Household Appliances andSpeed Control of Three Phase Induction Motor using PLC and HMI