Modeling and Analysis of the Distribution Grid in the Presence of Electric Vehicles and Energy Storage Systems By Stephen M. Cialdea A Thesis Submitted to the Faculty Of WORCESTER POLYTECHNIC INSTITUTE In partial fulfillment of the requirements for the Degree in Master of Science In Electrical and Computer Engineering May 1st, 2014 Approved: Professor Alexander E. Emanuel Professor John. A. Orr Table of Contents Table of Figures ............................................................................................................................................. 3 Table of Tables .............................................................................................................................................. 5 Table of Equations ........................................................................................................................................ 6 1 Introduction .......................................................................................................................................... 8 2 Background ......................................................................................................................................... 10 2.1 Electric Vehicles .......................................................................................................................... 10 2.1.1 History of EVs ...................................................................................................................... 10 2.1.2 Current EV Technology ....................................................................................................... 13 2.1.3 EV Proliferation ................................................................................................................... 17 2.1.4 Effects on Distribution Grid ................................................................................................. 20 2.2 Outages and Feeder Upgrade ..................................................................................................... 22 2.3 Economic Justification Methods ................................................................................................. 25 2.4 Load Profiles ................................................................................................................................ 26 2.5 The Cost of Electricity ................................................................................................................. 31 2.6 Large Capacity Energy Storage Systems ...................................................................................... 33 2.6.1 Energy Storage Technologies .............................................................................................. 33 2.6.2 Use Cases ............................................................................................................................ 35 3 Development of the Modeling System ............................................................................................... 38 3.1 Substation and End Blocks .......................................................................................................... 39 3.2 Line Block .................................................................................................................................... 41 3.3 Transformer Block ....................................................................................................................... 43 3.4 Generation/Load Block ............................................................................................................... 45 3.5 Capacitor Block ........................................................................................................................... 45 3.6 Battery Energy Storage System Block ......................................................................................... 46 3.7 Economic Calculations ................................................................................................................ 47 4 BESS Algorithms .................................................................................................................................. 49 4.1 Dynamic Programming for Optimum Economic Operation ........................................................ 49 4.2 Power Flow Smoothing ............................................................................................................... 54 4.3 Peak Shaving ............................................................................................................................... 62 5 Stability Enhancement ........................................................................................................................ 64 6 Test Feeder Configuration .................................................................................................................. 67 7 Results and Analysis ............................................................................................................................ 68 7.1 Base Case .................................................................................................................................... 69 7.2 Electric Vehicle Penetration ........................................................................................................ 70 1 7.3 Photovoltaic Generation ............................................................................................................. 73 7.4 System with BESS ........................................................................................................................ 76 7.5 Electric Vehicle Penetration and Distributed Generation ........................................................... 78 7.6 BESS and Electric Vehicle Penetration ........................................................................................ 79 7.7 BESS, Electric Vehicle Penetration, and Photovoltaic Generation .............................................. 81 7.8 BESS for Stability ......................................................................................................................... 83 7.8.1 Simple Stability Example ..................................................................................................... 88 8 Conclusions ......................................................................................................................................... 97 References .................................................................................................................................................. 99 2 Table of Figures Figure 1: EV Timeline .................................................................................................................................. 11 Figure 2: United States Commute Time Census Data [6] ............................................................................ 13 Figure 3: Example Charging Profile of Nissan LEAF with Assumed Ramp Rates ......................................... 16 Figure 4: EV and PHEV Sales per Month ..................................................................................................... 18 Figure 5: Cumulative EV and PHEV Sales to Date ....................................................................................... 19 Figure 6: Residential Load Profile ............................................................................................................... 28 Figure 7: Small Commercial Load Profile .................................................................................................... 28 Figure 8: Medium Commercial Load Profile ............................................................................................... 29 Figure 9: Medium Industrial Load Profile ................................................................................................... 30 Figure 10: Large Industrial Load Profile ...................................................................................................... 30 Figure 11: 2012 Eastern Massachusetts LMP ............................................................................................. 32 Figure 12: Model Signal Flow ...................................................................................................................... 39 Figure 13: Ideal Response ........................................................................................................................... 40 Figure 14: Tuned Response ......................................................................................................................... 40 Figure 15: Substation Parameter Prompt ................................................................................................... 41 Figure 16: Line Block Signal Flow Diagram .................................................................................................. 42 Figure 17: Line Block Parameter Prompt .................................................................................................... 42 Figure 18: Transformer Parameter Prompt ................................................................................................ 44 Figure 19: Load/Generation Block Signal Flow Diagram ............................................................................. 45 Figure 20: Battery Energy Storage System Parameter Prompt .................................................................. 46 Figure 21: Battery Energy Storage System Block Signal Flow Diagram ...................................................... 47 Figure 22: Simple Map ...............................................................................................................................