1. Fall 2003Electric Power Engineering Professor Charles A. Gross Electrical and Computer Engineering VOX 334.844.1812 FAX 334.844.1809 gross@eng.auburn.edu ELECTRICAL POWER ENGINEERING Restricted permission to use this copyrighted material for personal education is granted to all students officially enrolled in Busi/Engr 3510 in the 2003 Fall Semester at Auburn University. Any other use is strictly prohibited.

2. Fall 2003Electric Power Engineering © C. A. Gross 2 Perspectives ENGINEERING is... the application of science, mathematics, and technology to the design, fabrication, and use of practical devices and systems. ELECTRICAL Engineering is... that part of engineering which utilizes electrical and magnetic phenomena to achieve the engineering mission. Electrical POWER Engineering is... that part of electrical engineering which deals with the generation, transformation, transmission, and utilization of bulk electrical energy. It is characterized by high voltage, current, and power levels.

3. Fall 2003Electric Power Engineering © C. A. Gross 3 Power is flow rate of energy P = W/T W = Energy in joule (J) T = Time in seconds (s) P = Power in J/s, or watt (W) A joule is a watt-second; a "kilowatt-hour" (kW-hr) is 60 x 60 x 1000 = 3600000 joules = 3.6 MJ

4. Fall 2003Electric Power Engineering © C. A. Gross 4 Why energy in the electrical form? CONTROLLABILTY….Consider the incredibly precise control that must be employed to create a TV picture. EFFICIENCY….Generators, motors, transformers, lines, etc can be designed to have efficiencies above 95%. SPEED….can be transmitted at the speed of light. CONVERTABILTY….electrical energy can usually be easily converted to other form

5. Fall 2003Electric Power Engineering © C. A. Gross 5 Natural Electrical Energy Sources NONE (almost) Some possibilities… Static electricity (lightning, walking across the carpet) Bioelectricity (e.g. electric eels, fireflies) None is of sufficient capacity or practicality to use.

6. Fall 2003Electric Power Engineering © C. A. Gross 6 Electrical Energy Sources So where do we get electrical energy? We convert energy from other forms into electrical energy, primarily from mechanical. A device that converts mechanical energy into electrical energy is called a "generator".

7. Fall 2003Electric Power Engineering © C. A. Gross 7 An (Electrical) "Generator" A "Generator" is a device that converts energy (usually in mechanical form) into electrical form. INPUT POWER OUTPUT POWER P IN = T  P OUT = V I Torque x Angular Velocity Voltage x Current GENERATOR PRIME MOVER GRID T  - +V I-+V I-

8. Fall 2003Electric Power Engineering © C. A. Gross 8 (Electrical) Generation

9. Fall 2003Electric Power Engineering © C. A. Gross 9 Traditional Types of Generation: Hydro

10. Fall 2003Electric Power Engineering © C. A. Gross 10 Traditional Generation: Thermal

11. Fall 2003Electric Power Engineering © C. A. Gross 11 Thermal Energy Sources Fossil Fuels Coal Natural Gas Oil Biomass Nuclear Fuels Fission Fusion Solar (thermal) Geothermal

12. Fall 2003Electric Power Engineering © C. A. Gross 12 Emerging Generation Technologies Wind Power Solar-Electric (Photovoltaics) Fuel Cells Tidal (Oceanic) Power

13. Fall 2003Electric Power Engineering © C. A. Gross 13 Resistance (R – ohm,  ).... A fundamental loss mechanism in power transmission is "resistance (R) " (a measure of opposition to the flow of current). Ohm's Law.... Power Loss.... +V - IRIR

14. Fall 2003Electric Power Engineering © C. A. Gross 14 Transmission Loss Consider transmission of 100 MW through a line whose resistance is one ohm @ 100 V....

15. Fall 2003Electric Power Engineering © C. A. Gross 15 Transmission Loss Consider transmission of 100 MW through a line whose resistance is one ohm @ 100 kV....

16. Fall 2003Electric Power Engineering © C. A. Gross 16 Conclusion: Transmission of bulk electrical energy is practical only at high voltage! Hence, we need a device to "transform" voltage levels.

17. Fall 2003Electric Power Engineering © C. A. Gross 17 The Power Transformer I1+V1-I1+V1- I2+V2-I2+V2-

18. Fall 2003Electric Power Engineering © C. A. Gross 18 The Power Transformer

19. Fall 2003Electric Power Engineering © C. A. Gross 19 Power Transmission Lines

20. Fall 2003Electric Power Engineering © C. A. Gross 20 The Electric Power System... Generation Transmission Load Transformation

21. Fall 2003Electric Power Engineering © C. A. Gross 21 More Realistically…

22. Fall 2003Electric Power Engineering © C. A. Gross 22 For a large utility, typically... Tens of Generators Tens of major Tlines ("I-85") Scores of minor Tlines ("US 280") Hundreds of main distribution "feeders" ("College street") Tens of Thousands of distribution lines ("Tiger Street") Hundreds of Thousands of Transformers Millions of Loads

23. Fall 2003Electric Power Engineering © C. A. Gross 23 The US-Canadian Interconnected Grid Tens of major interconnected utilities About a 100 minor interconnected systems Distributed generation

24. Fall 2003Electric Power Engineering © C. A. Gross 24 System Operational Criteria No component may be overloaded. The voltage must be "near normal" at every point in the system. Power must be available instantly on demand. Power should be uninterruptible in the face of any reasonable combination of component failures. Generation must match load (plus losses) at all times. System should operate at near minimum cost. All players must meet their contractual obligations at each instant in real time.

25. Fall 2003Electric Power Engineering © C. A. Gross 25 Final Perspectives…. The studies of Mathematics and Science are two of the most worthy of human endeavors. Engineering uses M&S knowledge to provide practical solutions to problems related to human existence. Business, in partnership with Government, creates societal structures that provide the motivations and rewards for individuals to constructively participate in this process. Electrical Engineering achieves the engineering mission using electromagnetic systems and devices, and focuses on two general areas of application:  Information Processing  Energy Processing Both are critical to a modern functional civilization.