Clean and reliable energy. DTU Electrical Engineering, Technical University of Denmark

Transcription

1 Clean and reliable energy 1

2 UC- Denmark Summer School on Renewable Energy Systems UC Santa Cruz UC Davis, July August 2014 The Electric Power Grid Assoc. Prof. Chresten Træholt DTU Department of Electrical Engineering/CEE Denmark 丹麦 2

3 Outline Danish framework Basics on electricity and electric power The power system The smart grid PLDK (if time) Projects (rock stars) 3

4 Danish Gov. Energy Target towards % wind in the electricity system No coal 100% RE in electricity and heating systems 100% RE (incl. transport and industry) 4

5 Conversion path electricity [P. Douglass, 2013] Primary Sources Coal Oil Methane Biomass Wind Solar Legend Conversion Tools Furnace Combustion Engine Turbine Semi-Conductor Solar Thermal Collector Gassifier Fuel Cell Lamp Most Efficient Electric Devices Electric Motor Heat Pump LED Energy Services Transportation Materials Heat Cold Light Least Efficient 5

6 Electric Power System in Denmark General observations It appears that renewables are of importance for society and the world; to moderate impact on climate, ensure security of supply, promote green growth It appears that a transformation towards a sustainable energy system is on way Renewables and Conversion Efficiency favor Electricity Balancing renewables isn't easy at high penetration levels (intermittency) Present case Denmark (facts) Case: Wind power generation >30% of electricity demand in 2013 Funding: 20% of EU s Smart Grid R&D projects takes place in Denmark (ref: EU) Policy: Wind doubles to 50% in 2020; 100% RES in 2050 (ref: DK Parliament) Expectation: Electricity doubles to ~70% of the total energy system (ref: Climate commission) Response New technology and development of an intelligent power system (Smart Grid) is a prerequisite for efficient integration of high share of renewable energy 6

7 Smart Grid resolved? Technological challenges Storage, H2, battery Demand side management Real time market Coupling to the other systems Heat/cooling Transportation Waste water treatments/circulation pumps Gas infrastructure Curtailment (last resort) 7

8 Basics Danish framework Basics on electricity and electric power The power system The smart grid PLDK (if time) Projects (rock stars) 8

9 Where does electricity come from? 9

10 What is electricity? q I U P E DC + - AC 3 phase AC» H U=R*I P=U*I ~ 10

11 Power = Energy per unit time EE = PPPPPP EE 3.6kJ = W 3600s = Wh P = de/dt Units: W = J/s dddd dddd dp/dt Ramp rate dd 2 EE dddd 2 11

12 -> AC Lorentz force F= q(e + v B) 12

13 Electrical machines gen/motor sinusoidal Up Urms Uph-gr/Uph-ph P, Q and S Flux Φ U = ddφ dddd DC 13

14 Electrical machines gen/motor types Induction synchronous dc/pm Industry Ship propulsion Wind Circ. pumps Hydro Thermal Nuclear Some wind Appliances Cars Older industry Cell phones 14 DC

15 AC basics sinusoidal Voltage [kv] 2πf = ω f = 1/Τ Up Urms Load/impedance e( t) = ê sin(2 π f t + ϕ); f = 50Hz Degree msec Z R ωl RMS value : E T 2 ê RMS = e ( t) dt = 1 T P = 1/T e(t). i(t)dt ê. î sin 2 (ωt+ϕ)dt 0 2 ½. Ê. î =E rms. i rms Or P = E rms. i rms cosϕ 15

16 Active n reactive power P = E rms. i rms cosϕ = S cosϕ P, Q, S and power factor PF Combined Resistive and Inductive Load Instantaneous power can be negative!

17 3 phase P = E rms. i rms cosϕ = S cosϕ P, Q, S and power factor PF Power Factor P : PF = = cosϕ S S P Q Q S 2 2 S = P + Q 2 P

18 3 phase Up Urms Uph-gr/Uph-ph 30 degrees rotated Phase Voltages Line Voltages U R U U S RS U RT U U T ST U U U T R S = = = ^ U ^ U ^ U e e e jϕ π 180 2π j( +ϕ 3 2π j( +ϕ 3 π 180 ) π 180 ) 18 18

19 The Power System Danish framework Basics on electricity and electric power The power system The smart grid PLDK (if time) Projects (rock stars) Power plant Load 19

20 Power Systems must Balance Production and Consumption (power)

21 Transmission system California

22 Power system 3 phase + neutral + PE Well known components Generators (synchronous, frequency) Transformers (LV, MV, HV) Overhead lines Switches Cables Loads Power plant R S T N Load PE 22

23 The Power System OH lines or cables Switches/breakers Three phase, Single phase [figure from report on US-Canada black-out August 2004] 23

24 Power plant 24

25 Power plants 25

26 Power plants integrated design Amager waste incineration plant 26

27 Power system cables n OH 27

28 Power system transformers 28

29 Power system of west DK (2008) Production Capacity per voltage level US 765kV, 345kV, 230kV, 138kV US 69kV, 26kV 13kV, 4kV US 0.240kV, 0.120kV (double/single phase) DK 50Hz, US 60Hz

30 Balancing Must Occur at ALL time scales... Source: Amperion.net

31 Power system characteristics Objective: balance load & production, Hz Top-down power flow Production follows demand Large inertia (rotating machines) Protection schemes (protec. & safety) Well proven market (Nord Pool, ) Over dimensioned? 31

32 Smart Grid Danish framework Basics on electricity and electric power The power system The smart grid PLDK (if time) Projects (rock stars) Power plant Power plant Power plant Power plant Power plant Load 32 Power Power plant Power plant Power plant plant

33 Power Systems must Balance Production and Consumption (power)

34 Power and load curves Time 24h

35 DK Power generation landscape 35

36 Smart Grid high RE penetration 3 phase + neutral + PE New components Induction generators (microchp, freq.) Wind, batteries & PV (intermittent) Buck-boost/inverter electronics Rectifiers Cables Overhead lines Loads

37 Power system as of today! HV 30% MV LV 37 Smart Grid

38 Vision looking into what? HV X 50% MV LV 38 Smart Grid

39 Power plants 39

40 Power plants V2G inv BMS Battery Charger 40

41 Demand Must be Met at All Times (but flexible?) Source: Energy Policy, Volume 35, Issue 5, May 2007, Pages

42 Incentive

43 Technology monitoring n control Market place Software layer ICT net Electric grid Primary energy infrastructure

44 Coupling to other domains, & storage District heating, heat pumps Circulation pumps Electric vehicles Electric grid Primary energy infrastructure

45 Smart Grid Objective: balance load & production, Hz Bottom-up power flow (also) Flexible demand, demand response Lack of inertia (batteries, FC, ) Protection schemes (protec. & safety) Market? (aggregation) Distributed control by freq., prize incentive Lean dimensioned or oversized? 45

46 Clean and reliable energy