Conclusions. Fall 2010

Transcription

1 Conclusions ECEN 2060 Fall 2010

2 ECEN 2060 Topics Introduction to electric power system Photovoltaic (PV) power systems Energy efficient lighting Wind power systems Hybrid and electric vehicles 2

3 Electric Power System Introduction ti to electricity it generation, transmission and distribution Electric circuits, power and energy DC, single-phase AC, 3-phase AC Average and RMS values of voltages and currents Transformers Efficiency Background: Textbook Chapters 1 and 2 Chapter 3, Lectures 2-6, HW1-2, HW12, ME1 v ac i 1 1:n i 2 v 1 v 2 R i a I DC I w R w I R v a R y V DC DC-DC converter V T1 V T2 DC-DC converter 1 : n n :1 V R R v c v b i b i n R y R y Generator site Transmission cable Load site i c 3

4 PV power systems: Solar resource Clear-sky insolation at the Earth s surface: 1 kw/m 2 Hours of full sun kwh m 2 day Textbook Chapter 7 Lectures 6 and 7, HW 2, HW12, ME1 4

5 PV cell physics, and circuit model Photovoltaic effect in semiconductors,, hc/ > E g, efficiency limits PN junction PV cell circuit model VD I I D R SC I D I PV 0 ISC s R V D R p _ PV cell I V D PVcell I o e V p V D / V D T R 1 s I PV Textbook Chapter 8 Lectures 7-11, 13 HW3, HW12, ME1 5

6 PV modules and arrays _ I PV bypass diode V PV bypass diode Ipv [A] Open-circuit voltage, rated 4 voltage, short-circuit 3.5 current, rated current, rated 3 power, standard test 2.5 condition 2 Temperature effect Effect of shading, by-pass 0.5 diodes Vpv [V] Ppv [W] Textbook Chapter 8 Lectures HW4-6, HW12, ME Vpv [V] 6

7 Grid-connected PV systems I PV Energy-storage capacitor i ac PV array V PV Boost DC-DC converter C V DC Single-phase DC-AC inverter v ac AC utility grid DC-DC control DC-AC control System and component functions and control Maximum power point tracking System design and economics Textbook Chapter 9 Lectures 14, HW6, HW12, ME1 7

8 Power Electronics Switched-mode d power converter circuits, it pulse-width modulation Boost, buck, and buck-boost DC-DC converters Inductor volt-seconds balance, DC conversion ratio, switching ripples Power semiconductor devices Conduction and switching losses Averaged circuit models Efficiency Single-phase inverter Lectures HW5-6, HW12, ME1 V g I g 1:n I out V out n M ( D ) 1 1 D I g R L I out 1D : 1 V g I sw V out 8

9 Stand-alone PV systems System and component functions and control Battery charge control Reliability and economics Textbook Chapter 9 Lectures 20, HW7, HW12 9

10 Lead-Acid Batteries Porous lead Pb Lead dioxide PbO ev Sulfuric acid H 2 SO 4 H 2 O ev Cell chemistry and characteristics Capacity [Ah] depends on rate of discharge (Peukert s law) Energy efficiency, energy density, cost Types of lead-acid batteries Circuit model Charge management Battery charge controller Life cycles (DOD) Textbook Sections Lectures 20, 23 HW7, HW12, ME2 10

11 Energy efficient lighting Lighting energy, luminous flux, luminous efficacy Lighting technologies Solid-state (LED) lighting g Cost of light Lectures HW 8, HW12, ME2 11

12 Wind Power Systems Wind resource, power in the wind Wind turbine operation, Betz efficiency limit, power coefficient C p, tip speed ratio (TSR), power curve Drive trains: constant speed and variable speed architectures Mechanical torque, speed and power, gear box Variable-speed drive trains 3-phase AC machines 3-phase power electronics (rectifiers and inverters) Textbook, Chapter 6 Lectures HW 9, 10, 12, ME2 v n 1 Permanent-magnet synchronous generator stator windings a s b s c s variable-frequency variable-amplitude 3ac AC-AC constant frequency 3ac grid a b c 12

13 3-phase AC machines Rotating magnetic field Machine windings, poles, generation of magnetic flux Generation of torque, torque angle, motor or generator operation Synchronous machine Induction (asynchronous) machine Textbook Section 6.6 Lectures HW10, HW12, ME2 13

14 HEV s, PHEV s and EV s Vehicle traction power and performance specs HEV efficiency improvements Series drive train: sizing of components, battery energy storage, electric drives, efficiency, fuel economy and economics HEV, PHEV and EV drive train architectures Lectures HW 11,12 14

15 Final exam Tuesday, Dec 14, 7:30-10:00pm in class Comprehensive exam, covering materials from the entire semester Review class notes, textbook, HW, sample exams and midterm exam problems Calculators are allowed, but no devices with network or information storage capabilities are allowed Prepare notes You are allowed to have notes on both pages of one sheet (letter size) 15

16 Electrical Energy Engineering In the late 19 th century Electrical Engineering started the revolution in generation, transmission and distribution of Electric Power Nikola Tesla Tesla s polyphase ac power distribution, and motors/generators based on rotating magnetic field In the 20 th century, Electrical Engineering revolutionized Communication and Computing William Shockley, John Bardeen, Walter Brattain Transistor, Bell Labs, Dec quad-core processor, more than 500 million transistors Electrical Engineering g is now at the core of many existing and emerging green energy technologies 16

17 ECEN 2060 Objectives and Outline Introduction to Electrical l Energy Engineering i Improve generation Reduce consumption Renewable Energy Sources Photovoltaic power systems Wind power systems Transmission, Distribution, Conversion and Storage Energy Efficiency Energy efficient lighting Drives in hybrid and electric vehicles Understanding of electrical engineering fundamentals in renewable sources and energy efficient systems Practical knowledge of engineering i design issues in system examples Background and motivation for follow-up studies 17

18 Related and follow-up courses EE/ECE core courses 2260 Circuits as Systems, 2270 Electronics Design Lab, 3250 Microelectronics 2350 Digital Logic, 3350 Programming of Digital Systems, 3360 Digital Design Lab 3300 Linear Systems 3400 EM Fields Renewable Energy Track ECEN3170 Energy Conversion 1 (electromechanical and power systems) ECEN4167 Energy Conversion 2 (electric machines) Power Electronics Track ECEN4797 Introduction to Power Electronics ECEN4517 Renewable Energy and Power Electronics Lab 18

19 Beyond coursework Undergraduate research, teaching and service opportunities, CU College of Engineering Active Learning Research Discovery Learning Apprenticeship Undergraduate Research Opportunities Program (UROP) Teaching and service Earn-Learn Apprenticeship Summer Internships ECEE Department BS/MS program Efficiently earn MS degree _ MS.html Teaching Assistantship opportunities Research Assistantship opportunities 19

20 Research Project Example Grid-Interactive DC-Link PV Charging Station Satcon & CU-Boulder collaboration project sponsored by Hawaii Renewable Energy Development Venture CU-Boulder PI: Dragan Maksimovic (ECEE Department) Fast (Level-3) DC Chargers Grid-interactive inverter EV PHEV Utility Control Objectives Ultra high-efficiency, fast (Level 3) DC 100 charging of EV s and PHEV s directly 90 from the PV array and/or from the grid System 80 PV smoothing via built-in energy storage: vehicle-to-dc (V2DC) and four-quadrant grid-interactive inverter Optimum resource utilization Effective oil displacement, minimum carbon footprint power output without energy storage with V2DC

21 Research Project Example Field Study of Plug-In Hybrid Electric Vehicles Data Collection, Modeling and Analysis Study Partners University of Colorado at Boulder Toyota Motor Sales, USA Xcel Energy NREL Vehicle data Electricity data and charge management Fleet of 18 Toyota Prius PHV s in Boulder SmartGridCity TM The study s purpose is to learn about vehicle performance integration The study s purpose is to learn about vehicle performance, integration of the vehicles on the electric power grid, and the perceptions, preferences, and experiences of households with the PHVs

22 Thank you and good luck in the finals 22