Principles of Management

Naresh Kumar Goel HOD Electrical, Govt. Polytechnic, Ambala City Learning Objectives

 Define Managers And Management.

 Explain What Managers Do.

 Describe The Competencies Used In Managerial Work And Assess Your Current Competency Levels. Introductory Concepts: What Are Managerial Competencies?

. Competency – a combination of knowledge, skills, behaviors, and attitudes that contribute to personal effectiveness

. Managerial Competencies – sets of knowledge, skill, behaviors, and attitudes that a person needs to be effective in a wide range of positions and various types of organizations Why are Managerial Competencies Important?

 You need to use your strengths to do your best  You need to know your weaknesses  You need developmental experiences at work to become successful leaders and address your weakness  You probably like to be challenged with new learning opportunities  Organizations do not want to waste human resources  Globalization deregulation, restructuring, and new competitors add to the complexity of running a business A Model of Managerial Competencies

Communication Competency Planning and Teamwork Administration Competency Competency

Global Strategic Awareness Action Competency Self-Management Competency Competency A Model of Managerial Competencies

Communication Competency Planning and Teamwork Administration Competency Managerial Competency Effectiveness Global Strategic Awareness Action Competency Self-Management Competency Competency What Is An Organization?

 A formal and coordinated group of people who function to achieve particular goals  These goals cannot be achieved by individuals acting alone

Characteristics of an Organization

 An organization has a structure.  An organization consists of a group of people striving to reach goals that individuals acting alone could not achieve.

Management Organization Two or more people who work together in a structured way to achieve a specific goal or set of goals.

Goals Purpose that an organization strives to achieve; organizations often have more than one goals, goals are fundamental elements of organization.

The Role of Management To guide the organizations towards goal accomplishment - People responsible for directing the efforts aimed at helping organizations achieve their goals. - A person who plans, organizes, directs and controls the allocation of human, material, financial, and information resources in pursuit of the organization’s goals. Management

 Management refers to the tasks and activities involved in directing an organization or one of its units: planning, organizing, leading, and controlling.

 The process of reaching organizational goals by working with and through people and other organizational resources. Function: A classification referring to a group of similar activities in an organization like marketing or operations.

Functional Managers: A manager responsible for just one organizational activity such as accounting, human resources, sales, finance, marketing, or production . Focus on technical areas of expertise

. Use communication, planning and administration, teamwork and self- management competencies to get work done Basic Managerial Functions

Organizing

Planning Leading

Controlling Management and Organizational Resources Planning involves tasks that must be performed to attain organizational goals, outlining how the tasks must be performed, and indicating when they should be performed. Planning

. Determining organizational goals and means to reach them . Managers plan for three reasons

1. Establish an overall direction for the organization’s future 2. Identify and commit resources to achieving goals 3. Decide which tasks must be done to reach those goals Organizing means assigning the planned tasks to various individuals or groups within the organization and cresting a mechanism to put plans into action. Organizing

. Process of deciding where decisions will be made, who will perform what jobs and tasks, and who will report to whom in the company . Includes creating departments and job descriptions Leading (Influencing) means guiding the activities of the organization members in appropriate directions. Objective is to improve productivity. Leading

. Getting others to perform the necessary tasks by motivating them to achieve the organization’s goals

. Crucial element in all functions

1. Gather information that measures recent performance 2. Compare present performance to pre-established standards 3. Determine modifications to meet pre-established standards Controlling

. Process by which a person, group, or organization consciously monitors performance and takes corrective action Top Managers

. Responsible for providing the overall direction of an organization . Develop goals and strategies for entire organization . Spend most of their time planning and leading . Communicate with key stakeholders—stockholders, unions, governmental agencies, etc., company policies . Use of multicultural and strategic action competencies to lead firm is crucial Levels of Management

 First-line Managers: have direct responsibility for producing goods or services Foreman, supervisors, clerical supervisors  Middle Managers:  Coordinate employee activities  Determine which goods or services to provide  Decide how to market goods or services to customers Assistant Manager, Manager (Section Head)  Top Managers: provide the overall direction of an organization Chief Executive Officer, President, Vice President First-line Managers

. Directly responsible for production of goods or services . Employees who report to first-line managers do the organization’s work . Spend little time with top managers in large organizations . Technical expertise is important . Rely on planning and administration, self-management, teamwork, and communication competencies to get work done Middle Managers

. Responsible for setting objectives that are consistent with top management’s goals and translating them into specific goals and plans for first-line managers to implement . Responsible for coordinating activities of first-line managers . Establish target dates for products/services to be delivered . Need to coordinate with others for resources . Ability to develop others is important . Rely on communication, teamwork, and planning and administration competencies to achieve goals Introductory Concepts: What Are Managerial Competencies?

. Competency – a combination of knowledge, skills, behaviors, and attitudes that contribute to personal effectiveness

. Managerial Competencies – sets of knowledge, skill, behaviors, and attitudes that a person needs to be effective in a wide range of positions and various types of organizations Six Core Managerial Competencies: What It Takes to Be a Great Manager

 Communication Competency

 Planning and Administration Competency

 Teamwork Competency

 Strategic Action Competency

 Multicultural Competency

 Self-Management Competency Communication Competency

. Ability to effectively transfer and exchange information that leads to understanding between yourself and others . Informal Communication  Used to build social networks and good interpersonal relations . Formal Communication  Used to announce major events/decisions/ activities and keep individuals up to date . Negotiation  Used to settle disputes, obtain resources, and exercise influence  Deciding what tasks need to be done, determining how they can be done, allocating resources to enable them to be done, and then monitoring progress to ensure that they are done  Information gathering, analysis, and problem solving from employees and customers  Planning and organizing projects with agreed upon completion dates  Time management  Budgeting and financial management . Accomplishing tasks through small groups of people who are collectively responsible and whose job requires coordination . Designing teams properly involves having people participate in setting goals

. Creating a supportive team environment gets people committed to the team’s goals

. Managing team dynamics involves settling conflicts, sharing team success, and assign tasks that use team members’ strengths Strategic Action Competency

. Understanding the overall mission and values of the organization and ensuring that employees’ actions match with them

. Understanding how departments or divisions of the organization are interrelated

. Taking key strategic actions to position the firm for success, especially in relation to concern of stakeholders

. Leapfrogging competitors Multicultural Competency

. Understanding, appreciating and responding to diverse political, cultural, and economic issues across and within nations

. Cultural knowledge and understanding of the events in at least a few other cultures

. Cultural openness and sensitivity to how others think, act, and feel

. Respectful of social etiquette variations

. Accepting of language differences Self-Management Competency

 Developing yourself and taking responsibility

 Integrity and ethical conduct

 Personal drive and resilience

 Balancing work and life issues

 Self-awareness and personal development activities CIRCUIT BREAKER

WHAT IS A CIRCUIT BREAKER?

• A circuit breaker is an equipment that breaks a circuit either manually or automatically under all conditions at no load, full load or short circuit. Operating Principle

Two contacts called electrode remains closed under normal operating conditions. When fault occurs on any part of the system, the trip coil of the circuit breaker get energized and contacts are separated. Arc Phenomenon

• An arc is struck when contacts are separated. The current is thus able to continue. Thus the main duty of a circuit breaker is to distinguish the arc within the shortest possible time.

• The arc provides the low resistance path to the current and the current in the circuit remains uninterrupted.

The arc resistance depends upon the following factors.

Degree of ionization Length of the arc Cross Section of the arc Methods of Arc Extinction

High Resistance Method

Low Resistance Method TYPES OF CIRCUIT BREAKER

OIL AIR BLAST SF6 VACCUM CIRCUIT CIRCUIT CIRCUIT CIRCUIT BREAKER BREAKER BREAKER BREAKER Breaker Used In 132KV Grid Station

• Oil Circuit Breaker • Vacuum Circuit breaker • SF6 Circuit Breaker Bulk Oil Circuit breaker Air cushion Low Oil Circuit Breaker

Consists of two parts. Supporting Chamber. Circuit-Breaking chamber( consist of fixed and moving contact) Disadvantages Of Oil Circuit Breaker

• It is inflammable and there is a risk of fire. • It may form an explosive mixture with air. • It requires maintenance. • Absorbs moisture, so dielectric strength reduces. • Oil leakage problem. • Oil has to be replaced after some operations because of the carbonization of oil. Vacuum Circuit Breaker

• Vacuum is used as an arc quenching medium. • Have greatest insulating strength. • 10-7 to 10-5 pressure is to be maintained. • Used in 11KV panel in control room of grid station.

Vacuum Circuit Breaker Advantages

• Compact, reliable and have longer life. • No fire hazards. • No generation of gas during and after operation. • Can interrupt any fault current. • No noise is produced while operating. • Require less power for control operation. SF6 Circuit Breaker

1. Sulphur Hexafluoride (SF6) gas is used as an arc quenching medium. 2. SF6 is an electro-negative gas. 3. It has strong tendency to absorb electrons. 4. When contact are opened in a high pressure flow of SF6 gas, arc produced. 5. Free electron in the arc are captured by the gas. 6. Which build up enough insulation strength to extinguish arc. 7. it is much effective for high power and high voltages services, Advantages

• Simple construction, less cost. • SF6 gas is non flammable, non toxic & chemical inert gas. • Same gas is recirculated in the circuit. • Maintenance free C.B. • Ability to interrupt low and high fault current. • Excellent Arc extinction.

Advantages Of SF6 Over Oil Circuit Breakers

• Short arcing time • Can interrupt much larger currents • Gives noiseless operation due to its closed gas circuit • No moisture problem • No risk of fire • No carbon deposits. So no tracking and insulation problems • Low maintenance cost Transformer

An A.C. device used to change high voltage low current A.C. into low voltage high current A.C. and vice-versa without changing the frequency In brief, 1. Transfers electric power from one circuit to another 2. It does so without a change of frequency 3. It accomplishes this by electromagnetic induction 4. Where the two electric circuits are in mutual inductive influence of each other. Principle of operation

It is based on principle of MUTUAL INDUCTION. According to which an e.m.f. is induced in a coil when current in the neighbouring coil changes. Constructional detail : Shell type

• Windings are wrapped around the center leg of a laminated core. Core type

• Windings are wrapped around two sides of a laminated square core. Sectional view of transformers

Note: High voltage conductors are smaller cross section conductors than the low voltage coils Construction of transformer from stampings Core type

Fig1: Coil and laminations of Fig2: Various types of cores core type transformer Shell type

• The HV and LV windings are split into no. of sections • Where HV winding lies between two LV windings • In sandwich coils leakage can be controlled Fig: Sandwich windings Transformer with conservator and breather Working of a transformer

1. When current in the primary coil changes being alternating in nature, a changing magnetic field is produced 2. This changing magnetic field gets associated with the secondary through the soft iron core 3. Hence magnetic flux linked with the secondary coil changes. 4. Which induces e.m.f. in the secondary.

Ideal Transformers • Zero leakage flux: -Fluxes produced by the primary and secondary currents are confined within the core • The windings have no resistance: - Induced voltages equal applied voltages • The core has infinite permeability - Reluctance of the core is zero - Negligible current is required to establish magnetic flux • Loss-less magnetic core - No hysteresis or eddy currents Ideal transformer

V1 – supply voltage ; I1- noload input current ; V2- output voltgae; I2- output current Im- magnetising current; E1-self induced emf ; E2- mutually induced emf Phasor diagram: Transformer on No- load Transformer on load assuming no voltage drop in the winding

Fig shows the Phasor diagram of a transformer on load by assuming 1. No voltage drop in the winding 2. Equal no. of primary and secondary turns Transformer on load

Fig. a: Ideal transformer on load Fig. b: Main flux and leakage flux in a transformer Phasor diagram of transformer with UPF load Phasor diagram of transformer with lagging p.f load Phasor diagram of transformer with leading p.f load Equivalent circuit of a transformer

No load equivalent circuit:

Equivalent circuit parameters referred to primary and secondary sides respectively Transferring secondary parameters to primary side Transformer Tests

•The performance of a transformer can be calculated on the basis of equivalent circuit •The four main parameters of equivalent circuit are: - R01 as referred to primary (or secondary R02) - the equivalent leakage reactance X01 as referred to primary (or secondary X02) - Magnetising susceptance B0 ( or reactance X0) - core loss conductance G0 (or resistance R0) •The above constants can be easily determined by two tests - Oper circuit test (O.C test / No load test) - Short circuit test (S.C test/Impedance test) •These tests are economical and convenient - these tests furnish the result without actually loading the transformer

Electrical Machines

Open-circuit Test

In Open Circuit Test the trasforer’s secondary winding is open-circuited, and its primary winding is connected to a full-rated line voltage.

V Core loss  W  V I cos R  0 oc 0 0 0 0 I W w cos   oc V 0 V I X  0 0 0 0 I I or I  I cos c w 0 0 I G  w Usually conducted on I or I  I sin  I 2-I 2 0 • m  0 0 0 w V0 H.V side I0 I I0  V0Y0 ; Yo  B0  • To find V0 V0

(i) No load loss or core 2 Woc Woc  V0 G0 ; Exciting conductance G 0  2 loss V0 2 2 (ii) No load current Io & Exciting susceptance B 0  Y0  G0 which is helpful in

finding Go(or Ro ) and Bo (or Xo )

Short-circuit Test In Short Circuit Test the secondary terminals are short circuited, and the primary terminals are connected to a fairly low-voltage source The input voltage is adjusted until the current in the short circuited windings is equal to its rated value. The input voltage, current and power is measured.

• Usually conducted on L.V side • To find (i) Full load copper loss – to pre determine the efficiency

(ii) Z01 or Z02; X01 or X02; R01 or R02 - to predetermine the voltage regulation 2 Full load cu loss  Wsc  I scR01

Wsc R 01  2 I sc

Vsc Z01  I sc

2 2 X01  Z01  R01 Formula: voltage regulation

In terms of secondary values V V I R cos  I X sin % regulation  0 2 2  2 02 2 2 02 2 0 V2 0 V2 where '' for lagging and '-' for leading In terms of primary values V V ' I R cos  I X sin % regulation  1 2  1 01 1 1 01 1 V1 V1 where '' for lagging and '-' for leading Transformer Efficiency

Transformer efficiency is defined as (applies to motors, generators and transformers): P   out 100% Pin P   out 100% Pout  Ploss Types of losses incurred in a transformer: Copper I2R losses Hysteresis losses Eddy current losses Therefore, for a transformer, efficiency may be calculated using the following: V I cos   S S x100% PCu  Pcore VS IS cos Losses in a transformer

Core or Iron loss:

Copper loss: All day efficiency

out put in watts ordinary commercial efficiency  input in watts

output in kWh   ( for 24 hours) all day Input in kWh

•All day efficiency is always less than the commercial efficiency Introduction to Energy

Solar Energy

1 Definition of Energy: Energy can be defined as the ability (or) capacity to do work The different forms of energy: Energy can be obtained in number of way. It may be in the form of

(1) Chemical energy - due to chemical reaction (2) Electrical energy - due to flow of electron (3) Heat energy - due to thermal vibration (4) Light energy - due to radiation of light (5) Mechanical energy – due to moving parts (6) Nuclear energy - due to nuclear reaction The SI unit of energy is Joule (or) N/m.

2 Law of conservation of energy

According to law of conservation of energy, Energy can neither be created nor destroyed. But, one form of energy can be converted to another form.

Example:

 A battery generates electrons from chemical reactions, which are used to make electrical energy.

 A heater convert electrical energy into heat energy.

 The human leg converts the chemical energy stored in the muscles into mechanical energy when you pedal a bicycle.

3 Category of energy resource On the basis of availability, the energy resources are broadly categories as,

• Primary energy resources • Secondary energy resources

Primary energy: All energy originates from natural sources such as coal, solar, wind, hydro are called primary energy resources.

Secondary energy: The energy converted from primary energy sources. For example, the solar energy can be converted into electricity

4

Types of Energy sources 1. Conventional energy sources (or) Non-renewable energy sources 2. Non-Conventional energy sources (or) Renewable energy sources (1) Conventional energy (or) Non-renewable energy Conventional (or) Non-renewable energy sources are those, which cannot be replaced continuously.

• Generally, non-renewable energy sources come out of the ground as liquids, gases and solids.

Examples: The conventional (or) Non-renewable energy sources are Oil, Coal, Petroleum and natural gas, Nuclear energy

5 Non-Conventional energy (or) Renewable energy Renewable energy is a source of energy that can never be exhausted and can be replaced continuously

We can obtain renewable energy from the sun, from the water, from the wind, from crop residues and waste

The types of Non-conventional (or) Renewable energies are

Solar energy Tidal energy Wind energy Hydro energy Biomass energy Biofuels Geothermal Wave Power

6 Solar energy

Solar energy comes from the light of the sun, which means it is a renewable source of energy. We can use the sun light to create pollution free electricity

The solar cell is the system used to convert the sunlight energy into electrical energy

7 Solar collectors

8 Areas of the world with high Solar radiation

• The basic resource for all solar energy systems is the sun.

• Knowledge of the quantity and quality of solar energy available at a specific location is of prime importance for the design of any solar energy system

9 • Although the solar radiation is relatively constant outside the earth's atmosphere, local climate influences can cause wide variations in available radiation on the earth’s surface from site to site.

• In addition, the relative motion of the sun with respect to the earth will allow surfaces with different orientations to intercept different amounts of solar energy.

• It is the primary task of the solar energy system designer to determine the amount, quality and timing of the solar energy available at the site selected for installing a solar energy conversion system.

10 LVDT

• You’re expected to learn – Linear Variable Differential Transformer (LVDT) • Architecture • Diagram • Application

1 LVDT-Inductive T

A reliable and accurate sensing device that converts linear position or motion to a proportional electrical output.

2 LVDT

The cross sectional view of the DC LVDT at left shows the built-in signal conditioning electronics module. The module is secured with a potting compound that is not shown in this drawing

3 Applications of LVDTs

4 LVDT

Among the advantages of LVDT are as follows:

• It produces a higher output voltages for small changes in core position. • Low cost • Solid and robust -capable of working in a wide variety of environments. • No permanent damage to the LVDT if measurements exceed the designed range.

5 LVDT

Primary Secondary

A A

B B

An inductor is basically a coil of wire A transformer is made of at over a “core” (usually ferrous) least two coils wound over the It responds to electric or magnetic core: one is primary and fields another is secondary Inductors and tranformers work only for ac signals Vout VA VB 6 EXAMPLES OF LVDT APPLICATION

7 LVDT Operation

Windings are connected “series opposing” polarities of V1 and V2 oppose each other if we trace through the circuit from terminal A to B.

If the core at the center, V1=V2, Vo=0 When the core is away from center

toward S1, V1 is greater than V2 and the output voltage Vo will have the polarity V1. When the core is away from center

toward S2, V2 is greater than V1 and the output voltage Vo will have the polarity V2.

8 LVDT Operation

That is, the output ac voltage inverts as the core passes the center position The farther the core moves from center, the greater the difference in

value between V1 and V2, consequently the greater the value of

Vo.

Thus, the amplitude of Vo is a function of the distance the core has moved, and the polarity or phase indicates which direction is has moved. If the core is attached to a moving object, the LVDT output voltage can be a measure of the position of the object.

9 LVDT Operation

10 Example

An ac LVDT has the following data; input 6.3V, output 5.2V, range ±0.50 cm. Determine: a) Plot of output voltage versus core position for a core movement going from +0.45cm to -0.03cm? b) The output voltage when the core is -0.35cm from the center? c) The core movement from center when the output voltage is -3V? d) The plot of core position versus output voltages varying from +4V to -2.5V.

11 Student’s activity for next class

• Based on each measurement, I expect you to gather all the information in the following order – Type sensors – Architecture – Operation – Application – Diagram • You will need to prepare study materials/notes based on the information above • I will collect them by the end of next class (soft copy)

12 PLC’s Are ... • Similar to a Microcontroller: – Microprocessor Based – Onboard Memory for Storing Programs – Special Programming Language: Ladder Logic – Input/Output Ports PLC’s Are...

• Dissimilar to Microcontrollers: – Intended for Industrial Applications – I/O Designed to interface with Control Relays – Emphasis on Maximum Reliability PLC’s

• Widely Applied in Every Industry • Were Developed to Simplify the Implementation of Control Automation Systems in Plants and Assembly Lines • Designed to Minimize the Number of Control Relays in a Process and Maximize the Ways Relays can be Used • First Applied to Automobile Industry in the Late 1960’s • Flexible, Reliable and Low Cost PLC Components

I/O Modules

• Input Modules: Input Signals can be AC or DC, Analog or Digital • Output Modules: Outputs are either AC or DC Analog Signals (Although it is possible to ‘Construct’ Digital Outputs) • Modern PLC’s have Expansion Ports to Increase the Number of Available Inputs and Outputs Examples of I/O Signals • Inputs: – Pushbutton (Energizing or Grounding an Input) – Relay Contact Output – DC Voltage Level – Digital Logic Signal (+5V or 0 V, etc) • Outputs: – 24 V ac – 120 V ac – 120 Vdc – etcetera

PLC’s Use Ladder Logic

• Ladder Logic Diagrams Provide a Method to Symbolically Show How Relay Control Schemes are Implemented • Relay Contacts and Coils, Inputs and Outputs lie on “Rungs” Between the Positive and Ground Rails Example of Ladder Diagram Relays

• In General, Relays Transform a Control Signal into a Control Action • Relays Provide: – Isolation Between Input and Output – Leverage (Small Signal Can Control Large Action) – Automation (Minimize Human Interaction with a Control Process) Relay Applications

• Relays can be Designed to Perform Many Functions – Detect Out of Limit Conditions on Voltages and Currents – Start Motors – Prevent Motors from Over Heating – Control Assembly Lines – Adjust Lighting

PLC Timers and Motor Protection Industrial Communications

• RS-422 (EIA 422): Asynchronous Serial Communications , similar in many respects to RS-232 • Faster (up to 100 Kbps) than RS-232 • Better Noise Immunity – Differential (Balanced signal) Protocol – Makes use of Twisted Pair lines - 1 pair for transmit, one pair for receive (4 Lines vs. 3) EIA-422 Basics

• Can be 1 Master Transmitter feeding up to 10 Slave Receivers • Can be Peer-to-Peer, like RS-232 • Data is sent and received via Differential Ports - Common Mode Rejection (Noise common to both inputs is attenuated) • Twisted Pair also reduces EMI at low cost EIA 485 (RS-485) • More Modern, Faster and Flexible (supports TCP/IP) • Since it uses a differential balanced line over twisted pair (like EIA-422), it can span relatively large distances (up to 4000 feet or just over 1200 metres). • In contrast to EIA-422, which has a single driver circuit which cannot be switched off, EIA-485 drives need to be put in transmit mode explicitly by asserting a signal to the driver. This allows EIA-485 to implement linear topologies using only two lines. IEEE 802.3 (Ethernet) • Star Topology (Hub and spokes) • Standard for computer networks since the 1990’s • Becoming more and more popular in Industrial settings • Uses twisted pair data cables terminated in 8P8C (sometimes incorrectly called RJ45) modular plugs, wired according to TIA/EIA- 568-B Twisted Pair Cables

• Twisting a pair of wires that act as a communication channel will: – Minimize the loop area between the pair (minimize the self-inductance and capacitance) – Which in turn tends to cancel out much of the electromagnetic interference from external sources and crosstalk from adjacent pairs – Improve the efficiency of the channel PLC Special Features

• Time Delay Relays • Counter Relays • Special Functions • User Defined Functions • Special Bits Time Delay Relays

• When TD Relay Pick-Up Coil is Energized, a Delay is Initiated • Normally Open Contacts Wait to Close until Delay is Completed • Normally Closed Contacts Wait to Open until Delay is Completed • Very Useful for Creating a Sequence of Control Events Making Use of Delays • Delay Motor Start While Alarm Sounds for Safety Counters • Counter Relays must “Count” a pre- determined number of events before changing contact status • Can Count Up (UpCounter) or Count Down (DownCounter) • e.g. An UpCounter is set to 8 and is programmed to detect every occurrence of a 5 Volt pulse. When it has detected 8 such occurrences, the NO Contacts close and the NC contacts open. • Great for making Real-Time Clocks, etc Special Functions

• Modern PLCs can perform many Math and Logic Functions without additional Ladder Logic Programming – Differentiation, Integration – +, -, *, / – Boolean Logic Functions (AND, NOT, OR) – Master Control Functions (Reset, etc) Motor Protection

• Essential Part of Motor Control • Protect against: – Under Voltage – Under Frequency (AC Machines Only) – Over Current – Over Heating – Over Speed – Over Load Motor Protection Schemes

• Incorporated Directly in Ladder Logic Control Schemes ELECTRIC TRACTION INTRODUCTION:

 The locomotion in which the driving force is obtained from electric motor is called the electric traction system.  There are various system of electric traction existing such as electric train, trolley buses, diesel-electric vehicles and gas turbine electric vehicles ELECTRIC TRACTION SYSTEM MAJOR CLASSIFICATIONS OF TRACTION

 Non-electric traction: examples steam engine drive ic engine drive  Electric traction: examples diesel electric drive gas turbine electric drive

REQUIREMENTS OF AN IDEAL TRACTION SYSTEM

 The starting tractive effort should be high so as to have rapid acceleration.  The wear on the track should be minimum.  The equipments should be capable of withstanding large temporary loads.  Speed control should be easy.  Pollution free.  Low initial and maintenance cost.  The locomotive should be self contain and able to run on any route.

MERITS OF ELECTRIC TRACTION

 High starting torque.  Less maintenance cost  Cheapest method of traction  Rapid acceleration and braking  Less vibration  Free from smoke and flue gases hence used for underground and tubular railway. DEMERITS OF ELECTRIC TRACTION

 High capital cost.  Problem of supply failure.  The electrically operated vehicles have to move on guided track only.  Additional equipment is required for achieving electric braking and control.

DIFFERENT SYSTEMS OF TRACTION:

 Direct steam engine drive  Direct IC engine drive  Steam electric drive  IC engine electric drive  Petrol electric traction  Battery electric drive  Electric drive IC ENGINE ELECTRIC DRIVES SUPPLY SYSTEMS FOR ELECTRIC TRACTION:

 D.C system  A.C system  Single phase  Three phase  Composite system  Single phase AC to DC  Single phase to three phase

SPEED TIME CURVE FOR TRAIN MOVEMENT

 Acceleration  Constant acceleration  Speed curve running  Free run or constant speed period  Coasting period  Retardation or braking period

TYPICAL SPEED TIME CURVES FOR DIFFERENT SERVICES

 Urban or city services  Sub urban services  Main line services

TYPES OF SPEED IN TRACTION  crest speed  Average speed  Schedule speed

FACTORS AFFECTING ENERGY CONSUMPTION

 Distance between the stops.  Train resistance  Acceleration and retardation.  Gradient  train equipment. TRACTION MOTORS

 DC series motor  Ac series motor  Three phase induction motor

TRACTION MOTOR ELECTRICAL FEATURES

 High starting torque  Simple speed control  Regenerative braking  Better commutation  Capability of withstanding voltage fluctuations. MECHANICAL FEATURES  Light in weight.  Small space requirement.  Robust and should be able to withstand vibration. TRACTION MOTOR CONTROL

 Rheostat control  Series parallel control  Field control  Buck and boost method  Metadyne control  Thyristor control  Phase control  Chopper control

BRAKING

ELECTRIC BRAKING  Plugging or reverse current braking  Rheostatic braking  Regenerative braking  DC shunt motor  DC series motor  Induction motor MECHANICAL BRAKING  Compressed air brakes  Vacuum brakes MAGNETIC TRACK BRAKES

RECENT TRENDS IN ELECTRIC TRACTION

 Tap changer control  Thyristor control  Chopper control  Micro processor control

MICRO PROCESSOR CONTROL

QUESTIONS ? “If fail to Plan, you plan to fail” THANK YOU