ROBUST RAPID PROTOTYPING SYSTEM FOR MODEL PREDICTIVE CONTROL OF SINGLE ZONE RESIDENTIAL BUILDINGS by Maxwell Thomas Harris A thesis submitted to the Faculty and the Board of Trustees of the Colorado School of Mines in partial fulfillment of the requirements for the degree of Master of Science (Mechan- ical Engineering). Golden, Colorado Date Signed: Maxwell Thomas Harris Signed: Dr. Paulo Cesar Tabares-Velasco Thesis Advisor Golden, Colorado Date Signed: Dr. Gregory Jackson Department Head Department of Mechanical Engineering ii ABSTRACT Buildings in the United States are responsible for around 75% of total electric energy usage. Advanced controls are one way to minimize the energy use and cost; however, they require co-simulation platforms to study the effects on buildings and occupants. This thesis develops a platform to simulate advanced air conditioning controllers using model predictive controls (MPCs). MPCs require the use of co-simulation software which includes building energy simulation (EnergyPlus), optimization (AMPL), and MATLAB software used for simulation and investigation. MPCs require fast energy models as MPCs might require thousands of iterations to find an optimal solution. Thus, the platform uses an autoregressive statistical reduced order model (ROM) that quickly predicts building cooling energy use. Nine case studies test the newly developed platform with a residential building in Austin, Texas, under three different variable electric rates, along with three baseline temperature controllers. Results show that the developed MPC can save upwards of 29% energy while, at the same time, reducing cost by upwards of 45%. iii TABLE OF CONTENTS ABSTRACT ......................................... iii LISTOFFIGURES .....................................vii LISTOFTABLES...................................... xi LISTOFABBREVIATIONS ................................xii ACKNOWLEDGMENTS ..................................xv DEDICATION ........................................xvi CHAPTER1 INTRODUCTION ...............................1 1.1 ResearchObjectives. .. ....3 1.2 TechnicalApproachOverview . ....4 1.3 ThesisContributions . ....5 1.4 ThesisOrganization.............................. ....6 CHAPTER2 LITERATUREREVIEW . .7 2.1 MPC..........................................7 2.2 ROM.........................................12 2.3 Co-SimulationSoftware. .... 16 CHAPTER 3 REDUCED ORDER MODELS FOR RESIDENTIAL AND COMMERCIALBUILDINGS. 18 3.1 Introduction.................................... 18 3.2 BlackBoxModelingMethodDevelopment . ..... 21 3.3 SelectionofInputParameters . ..... 29 iv 3.3.1 ROMDevelopmentandValidation . 30 3.4 Discussion...................................... 34 3.5 Conclusion...................................... 35 CHAPTER 4 MODELING PLATFORM FOR BUILDING OPTIMIZATION-BASEDCONTROL . 37 4.1 Introduction.................................... 37 4.2 PrototypingPlatformDevelopment . ...... 40 4.3 CasestudyEnergyPlusModel . 42 4.4 ReducedOrderModel ............................... 43 4.5 MPCOptimizationModel . 45 4.5.1 Mathematical Formulation of the MPC Model . .... 46 4.6 SimulationandResults. 49 4.6.1 Prediction Horizon Parametric Analysis. ..... 49 4.6.2 MPCSimulation .............................. 52 4.6.2.1 Day Ahead Market Price (DAMP) Simulation Results . 52 4.6.2.2 Time-of-use (TOU) Simulation Results . 55 4.6.2.3 Time-of-use (EZ3) Simulation Results . 58 4.6.2.4 EnergyandCostSavingsResults . 58 4.7 Discussion...................................... 60 4.8 ConclusionandFutureWork. 62 CHAPTER5 CONCLUSION................................ 63 5.1 ResearchContributions. .... 63 5.1.1 DevelopmentofaROM . 64 v 5.1.2 Development of a Rapid MPC Prototyping Platform . ..... 65 5.2 BroaderImpact ................................... 66 5.3 FutureWork.....................................67 REFERENCESCITED ................................... 68 APPENDIX A - PLOTS OF INDIVIDUAL ZONES ON MULTIPLE ZONE ARC FIT . 77 APPENDIX B - ROM WEIGHTING MATRIX VALUES . 87 APPENDIX C - PLOTS NOT SHOWN FOR MPC SIMULATIONS . 93 vi LIST OF FIGURES Figure 1.1 MPC Modeling Environment Control Loop. ........3 Figure 2.1 Represents the receding horizon for an MPC over two time-steps. .8 Figure3.1 SystemIdentificationFlowchart. ....... 22 Figure3.2 Singlezoneresidentialbuilding. .........23 Figure3.3 Fivezonecommercialbuilding. ...... 23 Figure 3.4 System identification program used in Simulink. ...........26 Figure 3.5 A zoomed version of system identification model building on addition oftheperturbationtosystem. 27 Figure 3.6 ARMAX ROM vs EnergyPlus comparison of single zone building. 31 Figure 3.7 ARMAX ROM vs EnergyPlus comparison of single zone building. 31 Figure 3.8 ARX ROM vs EnergyPlus comparison of 5 zone building training data. Core zone is located on left and perimeter 4 zone located on right . 32 Figure 3.9 ARX ROM vs EnergyPlus comparison of 5 zone building validation data. Core zone is located on left and perimeter 4 zone located on right . 32 Figure 4.1 Represents the receding horizon for MPC over two timesteps.. 39 Figure 4.2 MPC Modeling Environment Control Loop. ....... 41 Figure 4.3 Simulink interface with MLE+ and AMPL S-function for simulation of theMPC. ...................................42 Figure4.4 Singlezoneresidentialbuilding. .........43 Figure 4.5 Comparison plot indicating the price profile for either DAMP, TOU, or EZ3vs. occupancyusedwithintheMPCstudy . 50 Figure 4.6 Plot of the prediction horizon parametric analysis showing cost savings andenergysavingsvspredictionhorizon. 51 vii Figure 4.7 Temperature comparison for the MPC and a baseline, constant temperature, controller. Both are based on DAMP pricing with Indoor Air Temperature (IAT), set-point temperature (TSP), Outdoor Air Temperature(OAT),andOccupancy. 53 Figure 4.8 Temperature comparison for the MPC and a baseline, temperature setback, controller. Both are based on DAMP pricing with Indoor Air Temperature (IAT), set-point temperature (TSP), Outdoor Air Temperature(OAT),andOccupancy. 54 Figure 4.9 Electrical consumption results from the temperature comparison plots for the MPC and a constant temperature control based on DAMP pricing ....................................54 Figure 4.10 Electrical consumption results from the temperature comparison plots for the MPC and a temperature setback control based on DAMP pricing ....................................55 Figure 4.11 Temperature comparison for the MPC and a baseline, constant temperature, controller. Both are based on TOU pricing with Indoor Air Temperature (IAT), set-point temperature (TSP), Outdoor Air Temperature(OAT),andOccupancy. 56 Figure 4.12 Temperature comparison for the MPC and a baseline, temperature setback, controller. Both are based on TOU pricing with Indoor Air Temperature (IAT), set-point temperature (TSP), Outdoor Air Temperature(OAT),andOccupancy. 56 Figure 4.13 Electrical consumption results from the temperature comparison plots for the MPC and a constant temperature control based on TOU pricing . 57 Figure 4.14 Electrical consumption results from the temperature comparison plots for the MPC and a temperature setback control based on TOU pricing . 57 Figure 4.15 Temperature comparison for the MPC and a baseline precool controller. Both are based on the EZ3 pricing with Indoor Air Temperature (IAT), set-point temperature (TSP), Outdoor Air Temperature(OAT),andOccupancy. 58 Figure 4.16 Electrical consumption results from the temperature comparison plots for the MPC and the simple precool controller based on the EZ3 pricing . 59 Figure A.1 ARX ROM vs EnergyPlus comparison of 5 zone building, core zone shown. ....................................77 viii Figure A.2 ARX ROM vs EnergyPlus comparison of 5 zone building, perimeter 1 zoneshown. .................................78 Figure A.3 ARX ROM vs EnergyPlus comparison of 5 zone building, perimeter 2 zoneshown. .................................79 Figure A.4 ARX ROM vs EnergyPlus comparison of 5 zone building, perimeter 3 zoneshown. .................................80 Figure A.5 ARX ROM vs EnergyPlus comparison of 5 zone building, perimeter 4 zoneshown. .................................81 Figure A.6 ARX ROM vs EnergyPlus comparison of 5 zone building, core zone shown. ....................................82 Figure A.7 ARX ROM vs EnergyPlus comparison of 5 zone building, perimeter 1 zoneshown. .................................83 Figure A.8 ARX ROM vs EnergyPlus comparison of 5 zone building, perimeter 2 zoneshown. .................................84 Figure A.9 ARX ROM vs EnergyPlus comparison of 5 zone building, perimeter 3 zoneshown. .................................85 Figure A.10 ARX ROM vs EnergyPlus comparison of 5 zone building, perimeter 4 zoneshown. .................................86 Figure C.1 Temperature comparison for the MPC and a baseline, precool temperature, controller. Both are based on DAMP pricing with Indoor Air Temperature (IAT), set-point temperature (TSP), Outdoor Air Temperature(OAT),andOccupancy. 93 Figure C.2 Electrical consumption results from the temperature comparison plots for the MPC and a precool temperature control based on DAMP pricing ....................................94 Figure C.3 Temperature comparison for the MPC and a baseline, precool temperature, controller. Both are based on TOU pricing with Indoor Air Temperature (IAT), set-point temperature (TSP), Outdoor Air Temperature(OAT),andOccupancy. 94 Figure C.4 Electrical consumption results from the temperature comparison plots for the MPC and a precool temperature control