Smart-Box for Efficient Energy Utilization Group 68 Jaime Gaya Fuertes, Somnath Deshmukh & Ziheng Wu ECE 445 – Senior Design TA – Jackson Lenz

Introduction Consumer level energy sharing An innovative way to trade energy Increased flexibility in the energy market Economic and resourceful tool for renewable energy market

Objectives Trade system to allow purchase and sale of energy between a network of consumers independently Cloud system to collect information from every house Real time tracking of battery capacity and power consumption Central cloud Market analysis of current energy usage and market price evaluation User interface allowing consumer to interact with the cloud to sell or purchase energy

System Overview Hardware: – Power supply, Battery charger, Boost-buck converter, Linear rectifier – Power sensor, Microcontroller Software: – Microcontroller with WiFi Shield – Cloud database server, User interface

Block Diagram

Power System – General Schematic

Battery 3 cells V Li-ion chemistry 3600 mAh V max = 4.2 V V min = 3 V Source: Battery university

Rectifier Ripple =0.011 V

LT 1513 I max = 1.15 A (at 12.6 V) Max supply voltage = 30 V Charge any number of cells up to 20 Constant output 1% Voltage Accuracy for Rechargeable Lithium Batteries Source: linear technology

Battery charger (IC) R7> K

Ripple= Output voltage

Output current Ripple = A

Rectifier Battery charger PCB Design Output Input

LT8580 (main features) Boost Converter Input voltage: 2.55 – 40 V Max switch current at 1.5 MHz -> 1.5 A

Boost Converter V input = 11. V V output = 30 +/- 2 V

Ripple = V Output voltage

Input Output PCB Design

LT8609 (main features) Buck Converter Input voltage: 3V - 42 V 2 A max input / 3 A peak transient Efficiency above 90 %

Buck Converter V in = 30 +/- 2 V V out = 14 +/- 0.5 V

Ripple = V Output Voltage

Input Output PCB Design

RV table TaskRV TABLESIMULATION Rectifier14 +/- 1 V[ ] V Battery charger12.8 +/- 0.2 V 1.0 +/- 0.2 V [ ] V [0.996 – 1.036] A Boost converter30 +/- 2 V[ ] V Buck Converter14+ / V[ ] V

Power Sensor Requirements – – Input: 3.7V to 12.6V – Li-ion compatible – Multiple cell operation (2 series and 3 series) – Measures battery voltage, remaining capacity and state of charge of the battery – I2C communication

Choice 1 - LTC V battery gas gauge from Linear Technology 3.6V to 20V Operating range for Multiple cells 1% Voltage, current, charge accuracy I2C/SMBus interface

LTC-2943 Schematic

Design Considerations Advantages – – Simple circuit integration with battery and micro-controller – Low cost (ordered samples for free) Disadvantages- – 8-lead DFN Package – not suitable for integration with design

Choice 2 – BQ34Z100-G1 Supports Li-Ion Chemistry Uses Impedence Track™ technology for batteries from 3V-65V Supports 2 wire I2C communicatio n

BQ34Z100-G1

Design Considerations Disadvantages – Complicated circuit design – Expensive model with added components Solution – BQ34Z100-EVM Gas gauge evaluation module

Final Choice – BQ34Z100-EVM Supports Li-Ion chemistry BQ34Z100 circuit module I2C communication Uses Impedence Track™ technology for obtaining battery chemistry data

BQ34Z100-EVM

Testing and Integration Procedure – – Developed Arduino test code for obtaining battery chemistry data – Secured I2C connection using appropriate pull up resistors between arduino and EVM module Observation – – Non responsiveness from the gas gauge – Stagnant chemistry data received through I2C

Power Sensor Conclusion Repetitive incorrect values signify EVM is not configured EV 2300 component required for configuring battery chemistry algorithm for the EVM module Non-sustaining for our system

Software User Interface -Web Application Cloud Computing Unit -Data storage and back-end computing algorithm Arduino Programming with Wi-Fi Shield 101 -Data transmission between the micro controller and web server

User Interface Display the battery information Display the energy market information Allow users to request transactions and project information

User Interface Login page

User Interface Main page

User Interface Selling page

User Interface Market page

Pseudo Code of Transaction Algorithm

Cloud Computing Unit Web Server - Website domain: eventclicker.web.engr.illinois.edu eventclicker.web.engr.illinois.edu Database Server (MySQL) - private data - public data Computing Algorithm - Setting the market price - recommendation for the lowest price

Arduino Wi-Fi Shield 101 (Connected with Arduino mega 2560) -Send the measured data to the server -Keep receiving the trading state data from the server -Output signal from pin6 to relay Arduino Wi-Fi Shield Arduino mega 2560

Arduino Pseudo Code

More Software Details Tools used: C panel (MySQL, phpMyAdmin, etc.) Programming Language: -Arduino: C/C++ -Client: HTML&CSS -Server: php CSS Reference: Bootstrap

Challenges Unable to equip gas gauge functionalities, leading to loss of real data Faulty batteries not equipped for safe use Battery charging takes a long time – 1.1V increase in 9 hours – Not equipped for consumer use Proof of concept only for one-to-one power transfer

Future Hardware Development Finish the trade process Integrate solar panels for promoting the use of renewable systems Enable consumer grid level power sharing

Future Software Development Graphical and Dynamic Display of the Energy Fluctuation Actual Price Fluctuation Model Android/IOS apps

Smart-Box Future Goals Try to enable the proof of concept within a network of 4 batteries Integrate with renewable households or solar communities Enable efficient intra-household battery allocation

Credits Jackson Lenz

References Institute of Electrical and Electronics Engineers. 7.8 IEEE Code of ethics, 8.html D. Wart, Power Electronics. McGraw-Hill Education, "Arduino - ArduinoBoardMega2560." Arduino. Arduino, n.d. Web. March 1, “BQ34z100-EVM 1s to 16s Impedance Track fuel gauge battery evaluation module” q34z100-evm&tisearch=Search-EN-Everythinghttp:// q34z100-evm&tisearch=Search-EN-Everything

Questions?