EE 334: Power Systems
Course Overview Anupama Kowli
Indian Institute of Technology Bombay, India
Outline of Today’s Lecture
Introduction to each other Course overview Background and motivation
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My Background I was born and brought up in Mumbai, completed my B. E. in 2006 from University of Mumbai (VJTI) I got my Ph.D. in Electrical and Computer Engineering from University of Illinois at Urbana-Champaign in 2013 While at UIUC, I interned with Kema Inc and Pacific Northwest National Laboratory My research interests include power grid operations, resource planning, electricity markets, ancillary services and integration of emerging resources as well as technologies On a personal front, I am married to Prof. Ankur Kulkarni and am the proud mother of Ananya (she’s just completed 2 years) 3/1
Course Contents Evolution of Power Systems, Energy sources structure of bulk power systems, Basic three phase system concepts, Power system components: Generators, Loads, Transformers, Transmission Lines etc, Modeling, performance and constraints of these components, Formulation/solution of steady state equations for interconnected systems: Balanced and Unbalanced systems. Positive Sequence Network, Per Unit System, Ybus formation Simple example of a load-flow solution Introduction to generator swing equations and stability issues, Simple Example of Loss of synchronism Interconnected System Operation and Control: Operational Objectives, Frequency Control, Voltage Control and Power Flow Control: introduction to HVDC transmission and FACTS Economic Issues in Power Systems. Analysis of Faulted Power Systems and Protection: Unbalanced System Analysis using Sequence Components, Equipment Protection Schemes: Overcurrent, Differential and Distance Protection, Relay coordination Preventive Control and Emergency Control System Protection Schemes) Blackouts and Restoration 4/1
A Historical Perspective 1830’s – Discovery of electricity, development of generators 1860’s – Practical use of electricity with telegraph and arc lighting 1880’s – Setting up of electric distribution companies in UK, US, Germany,India; discovery of motors and transformers 1890’s – Introduction of three-phase systems 1900’s – Monopoly systems, growing reliance on electricity – electric trains, motor loads, and so on; privatization 2000’s – Increasing use of renewables, introduction of electric vehicles, complex electricity trading Electrification was called“the greatest engineering achievement of the 20th Century” by the National Academy of Engineering 5/1
A Look at Indian Scenario Growth of Installed Generating Capacity in India 300
Generating Capacity (GW)
250
200
150
100
50
0 1947
1950
1956
1961
1966
1969
1974 Coal
1979 Gas
1980 Diesel
1985 Nuclear
1990 Hydro
1992
1997
2002
2007
2012
2013
2014
2015
RES
Private sector foray into electricity business Emphasis on rural electrification 6/1
One Sychronized Indian Grid
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Associated Challenges
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Key Perspectives
System point of view Large-scale, nonlinear, interconnected system Modeling issues and assumptions entailed in system analysis Course objectives: teach analytic aspects of power systems study the modeling, analysis and problem formulation introduce major considerations in operations of power systems equip students with skills to read the relevant literature
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Power System Basics Major components Generators: produce electricity Loads: consume electricity Lines (T&D): transport energy from generators to loads
Three-phase AC systems generation and transmission equipment is usually 3-φ industrial loads are 3-φ residential and commercial loads are often 1-φ and distributed equally among the phases
Reliability and economics have driven the need for interconnection of power systems – it allows for transmission of power over a wider region with subsystems operating at different voltage levels 10 / 1
Power System Basics Generators are usually synchronous machines (except wind, solar), with output voltages typically ranging in 13.8 kV to 24 kV (except wind and solar with output voltages of few hundred volts) While residential loads usually operate at 220 V, commercial and industrial loads may consume power at voltage levels ranging upto a few kV The transmission network forms the backbone of the interconnection and operates at high voltages (110 kV and above) =⇒ lower losses Transformers are used to suitably step up/down voltages
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The Energy Delivery System Generators convert energy from one source to electricity while loads consume electricity produce heat, light, sound, mechanical energy, etc
The widespread use of electricity is due to its ability to transport and control efficiently and reliably 12 / 1
Fundamental Characteristics
Absence of large-scale storage capabilities results in a “just-in-time” type manufacturing system Constraints: physical laws, limits on generation and transmission Power flows through paths of least resistance, and the transfer is almost instantaneous Supply and demand balance is critically monitored at all times to prevent grid collapse Reliability, economics and environmental considerations are the key drivers in power system operation and planning
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Requirements from a Power System The system must track load continuously and maintain balance between supply and demand Electric power delivery by the system must meet minimum standards of power quality minimal frequency deviations minimal voltage fluctuations adequate reliability
System must be able to deliver power even when subjected to “credible” contingencies, such as the loss of a transmission line or outage of a generator System operator plays a crucial role in ensuring these requirements are met – analytical tools are needed to enable decision making This is a foundation course in power system analysis 14 / 1
Course Contents Evolution of Power Systems, Energy sources structure of bulk power systems, Basic three phase system concepts, Power system components: Generators, Loads, Transformers, Transmission Lines etc, Modeling, performance and constraints of these components, Formulation/solution of steady state equations for interconnected systems: Balanced and Unbalanced systems. Positive Sequence Network, Per Unit System, Ybus formation Simple example of a load-flow solution Introduction to generator swing equations and stability issues, Simple Example of Loss of synchronism, Interconnected system operation and control: Operational Objectives, Frequency Control, Voltage Control and Power Flow Control: introduction to HVDC transmission and FACTS Economic Issues in Power Systems, Analysis of Faulted Power Systems and Protection: Unbalanced System Analysis using Sequence Components, Equipment Protection Schemes: Overcurrent, Differential and Distance Protection, Relay coordination Preventive Control and Emergency Control System Protection Schemes) Blackouts and Restoration 15 / 1
Reference Books
Power system analysis by J. J. Grainger and W. D. Stevenson Electrical Energy System Theory by O. I. Elgerd Power System Analysis by A.R. Bergen and V. Vittal Modern power system analysis by D. P. Nagrath and I. J. Kothari Power System Stability and Control by P. Kundur
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Other Resources
Course/lecture notes from UIUC, UMD, UWash, Imperial College NPTEL: Power System Analysis and other courses for stability and mathematics Presentations by Tom Overbye, Daniel Kirschen, George Gross and others Google!!
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Grading Scheme
Midterm exam Final exam Two quizzes
45 % 30 % 25 %
Attendance is mandatory!∗
∗
Institute attendance policy will be followed
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