Smart Grid Coordination in the Process Industry

Transcription

1 Smart Grid Coordination in the Process Industry Donald J. Chmielewski

2 Presentation Outline What is the smart grid? (intuitive answer) What is the smart grid? (decomposed answer) Operation of smart grid coordinated processes Design of smart grid coordinated processes 2

3 Acknowledgements Current and Former Students: Jin Zhang Diego Franco Avery Brown David Mendoza-Serrano Oluwasanmi Adeodu Jianyuan Feng Benjamin Omell Ming Yang Technical Guidance and Informal Discussions: Gabriela Hug (ECE, CMU) Zuyi Li (ECE, IIT) Mats Larsson (ABB), Iiro Harjunkoski (ABB), Kiran Sheth (ExxonMobil) Don Bartusiak (ExxonMobil) Dennis O Brien (Jacobs) David Heitzer (EDF) Funding: National Science Foundation (CBET ) Wanger Institute for Sustainable Engineering Research (IIT) 3

4 What is the Smart Grid? Wikipedia: A smart grid is an electrical grid that uses information and communications technology to gather and act on information, such as information about the behaviors of suppliers and consumers, in an automated fashion to improve the efficiency, reliability, economics, and sustainability of the production and distribution of electricity. ABB Website: A smart grid is an evolved grid system that manages electricity demand in a sustainable, reliable and economic manner, built on advanced infrastructure and tuned to facilitate the integration of all involved. 4

5 What is the Smart Grid? $ $ $ $ $ $ $ $... $ $ $ $ $ $ $ $... Market Layer Cyber Layer Generator Generator Generator e - e - e - e - e - e - e - e - e - Transmission Network Physical Layer e - e - e - e - e - e - e - e - e - Consumer Consumer Consumer Smart Grid: The Basics What? Why? Who? How? (CEP, Aug 2014) 5

6 What s wrong with the Dumb Grid? Gas Turbines Coal Fired Consumers Nuclear A balance between power generation and power consumption must be maintained at all times. Consumer Demand 6

7 What s wrong with the Dumb Grid? Gas Turbines Coal Fired If demand is low then few generators needed Consumers Nuclear Consumer Demand 7

8 What s wrong with the Dumb Grid? Gas Turbines Coal Fired If demand is high then many generators needed Consumers Nuclear Consumer Demand 8

9 What s wrong with the Dumb Grid? Gas Turbines Coal Fired Consumers Nuclear Renewable Sources Consumer Demand 9

10 The Dispatch Problem Gas Turbines Coal Fired If demand is low and renewable high then some generators many need to be off-line Consumers Nuclear Renewable Sources Consumer Demand 10

11 The Dispatch Problem Gas Turbines Coal Fired If demand is high and renewable low then there may not be enough generators Consumers Nuclear Renewable Sources Consumer Demand 11

12 Some Solutions to the Dispatch Problem Gas Turbines Coal Fired Advanced The Smart Communication Grid Network Consumers Nuclear Renewable Sources Consumer Flexibility Demand Massive Energy Storage 12

13 What is the Smart Grid? $ $ $ $ $ $ $ $... $ $ $ $ $ $ $ $... Market Layer Cyber Layer Generator Generator Generator e - e - e - e - e - e - e - e - e - Transmission Network Physical Layer e - e - e - e - e - e - e - e - e - Consumer Consumer Consumer Smart Grid: The Basics What? Why? Who? How? (CEP, Aug 2014) 13

14 Centralized Power Systems Gas Turbines Consumers Coal Fired Electric Consumers Nuclear Utility Renewable Consumers 14

15 Deregulated Power Systems Gas Turbines Consumers Coal Fired Nuclear Independent System Operator I S Consumers Renewable O Consumers 15

16 Power Generation Cost and Electricity Price If demand is 600MW then, electricity Electricity Price ($/MWhr) price is $18/MW-hr Coal Plant Gas Turbine Power Output (MW) 16

17 Pay as Maximum Bid If demand is 1200MW then, electricity Electricity Price ($/MWhr) price is $33/MW-hr Coal Plant Gas Turbine Power Output (MW) 17

18 Time Dependent Pricing for Electricity Energy Value ($/MWhr) time (days) 80 Energy Value ($/MWhr) time (days) PJM Western Hub, Day-Ahead prices: June 1, 2001 through June 20, 2001, 18

19 Real-time Pricing for Electricity Electricity Price ($/MWhr) Electricity Price ($/MWhr) Texas Hub: July Time (days) Time (days) 19

20 Load-Serving Entity Gas Turbines Consumers Coal Fired I LSE Consumers Nuclear S LSE Renewables O LSE Consumers Electricity price to consumers is the annual average 20

21 Presentation Outline What is the smart grid? (intuitive answer) What is the smart grid? (decomposed answer) Operation of smart grid coordinated processes Design of smart grid coordinated processes 21

22 Time-Scale Decomposition Unit Commitments Operational Time-Scale Hours Real-time Optimization Optimal Power Flow Minutes Multivariate Constrained Control Frequency Control Seconds Regulatory (PID) Control Electric Power Network Chemical Plant Security Constraints and Contingency Response Seconds Safety Systems and Emergency Shutdown 22

23 The Transmission Network 23

24 Some Transmission Network Examples 6 Bus Network 118 Bus Network 24

25 Power System Model - Load Flow Analysis Bus 1 I 1 E 1 E 2 Bus 2 I 2 Bus 4 Bus 5 Bus 3 E 4 E 5 I 4 I 5 E 3 I 3 Voltage at each bus: E [ E1 E2 E3 E4 E5] T Current injected at each bus: I [ I1 I2 I3 I4 I5] Admittance Matrix gives voltage-current relation: T I YE 25

26 Load Flow Analysis Power Calculations Power injected at bus k: S * k EkYk E * * is complex conjugate S k PE k k Y * jq k E * k P k - Active Power Q k - Reactive Power U k - Voltage Magnitude k - Voltage Angle Voltage in phasor form: E k U k e j k 26

27 Load Flow Analysis (bus types) Source Buses P 1 Q 1 1 U 1 Bus 1 Bus 2 P 2 Q 2 2 U 2 Slack Bus Bus 4 Bus 5 Bus 3 P 4 Q 4 4 U 4 P 5 Q 5 5 U 5 Load Buses P 3 Q 3 3, U 3 27

28 Time-Scale Decomposition Unit Commitments Operational Time-Scale Hours Real-time Optimization Optimal Power Flow Minutes Multivariate Constrained Control Frequency Control Seconds Regulatory (PID) Control Electric Power Network Chemical Plant Security Constraints and Contingency Response Seconds Safety Systems and Emergency Shutdown 28

29 Frequency Control P 1 Q 1 1 U 1 Bus 1 Bus 2 P 2 Q 2 2 U 2 Bus 4 Bus 5 Bus 3 P 4 Q 4 4 U 4 P 5 Q 5 5 U 5 P 3 Q 3 3, U 3 29

30 Frequency Control Servo-loop at each generator Control Variable: System frequency Manipulated Variable: Active power Disturbance: Load power 30

31 Time-Scale Decomposition Unit Commitments Operational Time-Scale Hours Real-time Optimization Optimal Power Flow Minutes Multivariate Constrained Control Frequency Control Seconds Regulatory (PID) Control Electric Power Network Chemical Plant Security Constraints and Contingency Response Seconds Safety Systems and Emergency Shutdown 31

32 Optimal Power Flow? System operator selects generator states such that - all load demands are met: Pk and Q k - all buses satisfy voltage constraints: - all transmission lines are below limits: Optimizes with respect to - operating cost - transmission line losses - active and reactive reserves at loads fixed P 0.9 U 1.1p.u. km k Pkm P km U k X U km m max sin( m ) k 32

33 Time-Scale Decomposition Unit Commitments Operational Time-Scale Hours Real-time Optimization Optimal Power Flow Minutes Multivariate Constrained Control Frequency Control Seconds Regulatory (PID) Control Electric Power Network Chemical Plant Security Constraints and Contingency Response Seconds Safety Systems and Emergency Shutdown 33

34 Unit Commitment Problem Similar to Optimal Power Flow Explicit load flow analysis Optimizes with respect to - Costs, losses, reserves (same as OPF) - Integer variables for unit start-up and shut-down Larger horizon (day-ahead and hour-ahead) 34

35 Time-Scale Decomposition Unit Commitments Operational Time-Scale Hours Real-time Optimization Optimal Power Flow Minutes Multivariate Constrained Control Frequency Control Seconds Regulatory (PID) Control Electric Power Network Chemical Plant Security Constraints and Contingency Response Seconds Safety Systems and Emergency Shutdown 35

36 What if a generator trips off-line? Gas Turbines Coal Fired Consumers Nuclear A balance between power generation and power consumption must be maintained at all times. 36

37 Spinning Reserves and N-1 Security Q k P k 37

38 Time-Scale Decomposition Unit Commitments Operational Time-Scale Hours Real-time Optimization Optimal Power Flow Minutes Multivariate Constrained Control Frequency Control Seconds Regulatory (PID) Control Electric Power Network Chemical Plant Security Constraints and Contingency Response Seconds Safety Systems and Emergency Shutdown 38

39 The Not So Dumb Grid! 39

40 Centralized Operation Gas Turbines Consumers Coal Fired Electric Consumers Nuclear Utility Renewable Consumers 40

41 Decentralized Operation Gas Turbines Consumers Coal Fired I LSE Consumers Nuclear S LSE Renewables O LSE Consumers 41

42 Deregulated Operation 42

43 Consumer Participation 43

44 Presentation Outline What is the smart grid? (intuitive answer) What is the smart grid? (decomposed answer) Operation of smart grid coordinated processes Design of smart grid coordinated processes 44

45 Alcoa and Aluminum Smelting 40% of cost to produce aluminum is electricity Production is proportional to power input 45

46 Evolution of Alcoa Demand Response Hrs of Traditional Operations (470 MW) Hr Load Profile with Reliability Interruption 550 May 31, MW's of Direct Load Control Base Load Consumption Traditional Demand Response Dynamic Demand Response Smelting provides steady 24/7 grid load Limited collaboration with energy system Alcoa provides emergency shutdown capability Smelter a last resort ancillary service MISO remotely controls 75 MW of smelter load in real time Enables dynamic grid regulation 46

47 Chemical Processing Plants P 2 Electric Grid P 4 P 1 P 3 Hot Oil Based Utility Plant Hot Oil Utility 47

48 Hot Oil Utility Plant Hot Utility Oil (to the process) Cold Utility Oil (from the process) Fuel Furnace 48

49 Utility Plant with Electric Power Option Hot Utility Oil (to the process) Cold Utility Oil (from the process) Electric Heater Electric Power (from the grid) Fuel Furnace 49

50 Energy Costs in 2005 Energy Costs 2005 Energy Cost ($/MWhr) Electricity Natural Gas Day ofthe Year

51 Energy Costs 2008 and 2012 Energy Cost ($/MWhr) Electricity Natural Gas Energy Costs Day ofthe Year Energy Cost ($/MWhr) Electricity Natural Gas Energy Costs Day ofthe Year 51

52 Operating Profiles in 2005 Energy Rate (MW) or Cost ($/MWhr) Energy Rate (MW) or Cost ($/MWhr) Day ofthe Year Electricity Cost Fuel Cost Electric Power Fuel Usage Electricity Cost Fuel Cost Electric Power Fuel Usage Day ofthe Year

53 Comparison of 2008 and 2012 Energy Rate (MW) or Cost ($/MWhr) Electricity Price Fuel Price Electric Power Fuel Usage Day of the Year Energy Rate (MW) or Cost ($/MWhr) Electricity Price Fuel Price Electric Power Fuel Usage Day ofthe Year

54 Annual Operating Costs (in millions) Baseline $37.4 $32.9 $18.8 With Electric Heater $33.7 $30.3 $18.3 Savings $3.7 $2.6 $0.5 Percent Savings 10% 8% 3% 54

55 Presentation Outline What is the smart grid? (intuitive answer) What is the smart grid? (decomposed answer) Operation of smart grid coordinated processes Design of smart grid coordinated processes 55

56 Utility Plant with Electric Power Option Hot Utility Oil (to the process) Cold Utility Oil (from the process) Electric Heater Electric Power (from the grid) Fuel Furnace 56

57 Electric Heaters 57

58 Cost of Electric Heaters Cost of 5MW electric heater is $1.1 million Installed cost of 5MW heater is $3.3million If economy-of-scale is linear, then o 35MW installed is $23.1 million If economy-of-scale is 0.6 rule, then o 35MW installed is $10.6 million 58

59 Payback Period Savings from electric heater Heater Cost (Linear EOS) $3.7 $2.6 $0.5 $23.1 $23.1 $23.1 Payback (years) Heater Cost (0.6 Rule EOS) $10.6 $10.6 $10.6 Payback (years)

60 Utility Plant with Thermal Energy Storage Hot Utility Oil (to the process) Cold Utility Oil (from the process) Electric Power (from the grid) Heat Exchanger Electric Heater Fuel Furnace Molten Salt Energy Storage 60

61 Integrated Gasification Combined Cycle 61

62 Simplified view of IGCC N min PG ( t) t 0 1 C e ( t) P G ( t) n coal Compressed Air Storage (M A ) n s,a n C n ASU Gasification Block (Includes ASU Distillation, Gasifier and Acid Gas Removal) n H2 n s,h2 n G H 2 Storage (M H2 ) MAC ASU Main Air Compressor P C P N P G Power Block (Includes Expansion Turbine, Combustion Turbine, HRSG, and Steam Turbine) 62

63 Economic MPC operation Value of Electricity ($/MW) Power Generated (MW) H 2 in Storage (tonnes) Value of Electricity Time (days) EMPC Time (days) 500 EMPC Time (days) 63

64 Dispatch Requires Equipment Upgrade n coal Compressed Air Storage (M A ) n s,a n ASU Gasification Block (Includes ASU Distillation, Gasifier and Acid Gas Removal) n H2 n s,h2 H 2 Storage (M H2 ) n C n G MAC ASU Main Air Compressor P C P N P G Power Block (Includes Expansion Turbine, Combustion Turbine, HRSG, and Steam Turbine) Net Present Value analysis is required 64

65 Smart Grid Equipment Design Problem Design problem is a Stochastic Program min Equip Size PV f OpCost OpCost CapCost min 1 N 0OpVar k EqipSize k1 If no energy storage, then two-stage problem If energy storage is allow, then a multistage problem N InstOpCost ( OpVar k ) 65

66 A Solution Method Capital Cost = c c max M H 2 where 0,1 NPV(Equip Size) is non-convex Search over NPV min { Capital Cost + Operating Costs } Equipment Size Monte Carlo Simulation using EMPC Average Operating Cost 66

67 Neg Net Present Value NPV has Local Optima Equipment Variables 67

68 Neg Net Present Value Approximate NPV for Global Search Equipment Variables 68

69 Neg Net Present Value Starting Point for Gradient Search Equipment Variables 69

70 Novel Two-Step Solution Procedure Global Search over approximate NPV Initial Search Point Search over NPV min { Capital Cost + Operating Costs } Economic Linear Optimal Control (ELOC) as surrogate policy Equipment Size Monte Carlo Simulation using EMPC Average Operating Cost 70

71 ELOC Simulation Value of Electricity ($/MW) Power Generated (MW) Time (days) EMPC ELOC Value of Electricity Time (days) H 2 in Storage (tonnes) EMPC ELOC Time (days) 71

72 Economic ELOC Based Linear Design Optimal (Global Control Solution) min s, m, q, z, z, X,, Y, max min q, q s. t. s g ( D op op.cos.cos t t z q ( q ) max As Bm sqrt( diag( x X q D Y ) u X GwG ( AX BY ) z z T T Gp )) T g cap.cos t z z ( D q q q x ( q min, q min X DuY ) X ( AX BY ) X D s D m x max ) 0 u 0 Generalized Benders Decomposition Master Problem (BARON) Primal Problem (SDP solver) 72

73 Example of ELOC Based Design n coal Compressed Air Storage (M A ) n s,a n C n ASU Gasification Block (Includes ASU Distillation, Gasifier and Acid Gas Removal) n H2 n s,h2 n G H 2 Storage (M H2 ) MAC ASU Main Air Compressor P C P N P G Power Block (Includes Expansion Turbine, Combustion Turbine, HRSG, and Steam Turbine) Capital Cost = where and H 2 G H 2 0 H 2 c c G 0 H 2 1 c 0,1 0,1 G M c G 1 max H new P 0. 6 max max 0 M H 2 H 2M H 2 G max max 0 PG GPG 73

74 Discontinuous Non-convex Capital Costs Capital Cost (million $) Capital Cost (million $) max Hydrogen Storage Unit Size - M H2 (tonnes ) new New Power Block Size - P G (MW) 74

75 Grid Search and Two-Step Search 2000 Negative NPV Generated Power (MW) H 2 in Storage (tonnes) 75

76 EMPC with Different Equipment Sizes Value of Electricity ($/MW) Value of Electricity Time (days) Power Generated (MW) ELOC Search Gradient Search Time (days) 2000 H 2 in Storage (tonnes) Time (days) 76

77 Global Solution? 500 Negative NPV 400 NNPV ($10 6 ) Generated Power (MW) H 2 in Storage (tonnes) 77

78 Global Solution? Negative NPV NNPV ($10 6 ) Generated Power (MW) NNPV ($10 6 ) H 2 in Storage (tonnes) C e 20 2 $ / MWh 78

79 Change in Electricity Price Variance? 120 Negative NPV NNPV ($10 6 ) NNPV ($10 6 ) Generated Power (MW) H 2 in Storage (tonnes) C e 15 2 $ / MWh 79

80 Other Smart Grid Opportunities n coal Gasification Block (Includes ASU Distillation, Gasifier and Acid Gas Removal) n H2 n CO2 n L MeOH Plant n ASU CO2 Storage n s,c n s,h2 H 2 Storage Compressed Air Storage n s,a P CC CO 2 Compressor n G n C Air Compressor P AC P G Power Block (Includes Expansion Turbine, Combustion Turbine, HRSG, and Steam Turbine) P N 80

81 Conclusions Control of a power network is similar to that of a chemical plant. Market layer gives opportunities for chemical plants to lower operating costs / generate new revenue streams. Smart grid coordinated operation likely to require new or expanded equipment. Novel design strategy for smart grid coordinated systems has been proposed. 81

82 Other Smart Grid Opportunities n coal Gasification Block (Includes ASU Distillation, Gasifier and Acid Gas Removal) n H2 n CO2 n L MeOH Plant n ASU CO2 Storage n s,c n s,h2 H 2 Storage Compressed Air Storage n s,a P CC CO 2 Compressor n G n C Air Compressor P AC P G Power Block (Includes Expansion Turbine, Combustion Turbine, HRSG, and Steam Turbine) P N 82

83 Other Smart Grid Opportunities 83

84 District Cooling System 84

85 District Cooling System 85

86 District Cooling System with Storage 86