Machine-to-Machine Communications in Smart Cities Hussein T. Mouftah Tier 1 Canada Research Chair and Distinguished University Professor School of Electrical Engineering and Computer Science University of Ottawa email: mouftah@uottawa.ca
Outline Smart Cities Electric Vehicles Electric Vehicles and Smart Grid Connected Electric Vehicles Vehicle-to-Infrastructure Communications in Smart Cities Charging load control Energy trading with EVs Vehicle-to-Vehicle Communications in Smart Cities Summary
Smart City A city can be defined as smart when investments in human and social capital and traditional transport and modern ICT communication infrastructure fuel sustainable economic development and a high quality of life, with a wise management of natural resources, through participatory action and engagement.
Smart Cities Main Infrastructures Smart Grids Intelligent Transportation Systems
Electric Vehicles (EVs) General definition for EV: An electric vehicle contains one or more electric motors that contribute, partly or entirely, toward providing the motive force to drive the vehicle Various types of EVs Battery Electric Vehicles (BEV) no combustion engine Hybrid Electric Vehicles (HEV) combustion engine + electric engine Fuel Cell Electric Vehicles (FCV) electric engine supplied by fuel (hydrogen) cell Plug-in Electric Vehicles (PEV) Electric engine topped up from the power grid
Electric Vehicles EV technology is a forward step towards nations energyindependence Transportation accounts for approximately 72% of global oil demand EV operating cost is low Ownership is subsidized by governments EVs are relatively* clean Transportation contributes to one third of CO2 emissions Replacing 25% of the current gasoline-based vehicles with EVs can reduce annual GHG emissions up to 3.4 million tonnes *Electricity production also emits GHG but less than the transportation sector Emissions highly depend on energy mix Penetration of renewable resources can further reduce GHG emissions of EVs
Plug-in Electric Vehicles (PEVs) PEV batteries are charged from the power grid This is where smart grid gets into the picture
PEV Residential Charging PEV is a part of Home Area Network (HAN) Controlled by Home Energy Management System (HEMS) and PEV is not only charging but also discharging to top up home battery or supply electricity to appliances (V2H) Source: inhabitat.com
First Electric Vehicles First EVs produced in mid-19 th century Problems: Low cruising speed Heavy and unreliable batteries Source: IEEE the Institute
Electric Vehicles - Today Source: plugndrive.ca Source: TOYOTA <#>
Electric Vehicles - Today Source: plugndrive.ca Source: TOYOTA <#>
Electric Vehicles - Today Source: plugndrive.ca Source: TOYOTA <#>
Plug-in Electric Vehicles (PEVs) Two types of Electric Vehicle Supply Equipment (EVSE) AC Charging Level 1 & Level 2 DC Charging (Fast charging) Voltage Amps Power (kva) Charge Time for Chevy Volt Level 1 120 12 1.44 < 10 hrs Level 2 208-240 12-80 2.88-19.2 < 8 hrs DC Fast Charging 200-450 200 90 30min
Public and Residential EVSEs in Montreal Downtown Source: PlugShare
PEV Charging Load PEV charging can have positive or negative impacts Off-peak charging can reduce systems costs Filling up valleys and reducing start-up (ramping) costs of generators But, peak charging is a challenge
PEV Charging Load on Smart Grid Uncontrolled charging Peak charging may cause failures in the distribution system Insufficient supply Transformer overloading Exceeding conductor capacity Source:EPRI
Inter-Vehicle Communications for Electric Vehicles Electric vehicle to Road Side Unit (RSU) communications for electric vehicle monitoring VANET server controlled charging station reservation The role of Dedicated Short Range Communications (DSRC) and Wireless Access in Vehicular Environments (WAVE) in Connected Electric Vehicles
Connected Electric Vehicles (CEVs) Electric Vehicle-to-Infrastructure (EV2I) communications is required for: Smart charging load control Capacity planning for ramping generators and renewable output regulation Demand response or Direct Load Control (DLC) for other loads Vehicle-to-Grid (V2G) applications Supplying appliances with EV batteries Store-then-supply cheap or clean electricity Compensate for brownouts Regulation (through an aggregator)
Connected Electric Vehicles Today mostly EV2I communications are implemented CEVs talk with utilities, assets or suppliers In the near future, EV2EV communications will be demanded for applications such as: EVSE Reservation On-route charge planning Social networking And many more emerging applications
Communication Technologies for CEVs EV2I Communications Power Line Communications (Homeplug GP, Auto-Rem) Zigbee (IEEE 802.15.4) Wi-Fi (IEEE 802.11a/b/g/n/s) Cellular (3G, 4G, XG) Ethernet Intra-vehicle PLC and Ethernet VANETs for EVs
Power Line Communications (PLC) Uses existing power lines Easily integrates with intra-vehicle communication systems Integrated PLC-Zigbee solutions are available e.g., Hybrii-XL GV7011 System-on-Chip PLC for EV to EVSE communications Zigbee for EV to central EVSE system communications PLC is challenging due to overhearing issues and noise
Zigbee Alliance s Solution Zigbee is based on the IEEE 802.15.4 standard Its maximum data rate 250kbps (in 2.4GHz band) Its transceiver cost is much less than the cost of a battery Its transmission rates are fast enough to transmit the data needed every second as is required for frequency regulation services Its range is adequate to reach every EV in a large parking lot with only a small number of repeaters It is flexible; new devices can be added easily Zigbee Smart Energy is particularly designed for smart grid applications Zigbee Smart Energy Profile offers a global standard for IP-based control for energy management in Home Area Networks (HANs)
Zigbee A pilot project at Victoria, Australia, for integrating home energy management with EV charging: Utility issued Zigbee Smart Energy Demand Response/Load Control (DRLC) messages are mapped to EVSE Maximum current drawn by the EV is adjusted accordingly Source: Dius
Cellular Networks (GSM, CDMA, LTE, LTE-A, NG) Low Capital Expenditure (CAPEX) due to existing infrastructure E.g.,Qualcomm is developing chargers with cellular technology using Verizon infrastructure for 15,000 EVSEs Hochgraf et al. proposes to use the GSM network and SMS messages for charging control PEV information and utility commands are delivered via SMS messages If a feeder is overloaded the operator can interrupt charging by sending an SMS to the EVSE Downside is SMS messages are costly C. Hochgraf, R. Tripathi, and S. Herzberg, Smart Grid Charger for Electric Vehicles Using Existing Cellular Networks and SMS Text Mouftah Messages, MoWNet2016 in IEEE SmartGridComm 2010, pp. 167-172.
Ethernet Ethernet interface allows EVSE to share a common network with other EVSE devices and to be connected to the central EVSE system or server Most EVSE manufacturers support Ethernet Ethernet may be more reliable for indoor parking lots due to penetration problems of wireless signals
Wi-Fi Alliance s Solution Wi-Fi is adopted in many EVSEs E.g., GE WattStation comes with Wi-Fi connection Wi-Fi is also used for municipality scale networks IEEE 802.11a/b/g/n most popular standards IEEE 802.11s is the recent mesh network standard An integrated WIMAX and 802.11s based charging load control solution has been proposed by Erol- Kantarci et al. M. Erol-Kantarci, J. H. Sarker, H. T. Mouftah, Communication-based Plug-in Hybrid Electrical Vehicle Load Management in the Smart Grid, in Proc. of IEEE Symposium on Computers and Communications (ISCC), Corfu, Greece, June 28- July 1, 2011. 25/35
Charging Load Control via 802.11s When a PEV is plugged in, the EVSE communicates with the local substation control center (SCC) via 802.11s links SCC schedules charging based on utility set limits which are delivered through the WIMAX links The SCC and the EVSEs form a Wireless Mesh Network (WMN) using IEEE 802.11s EVSEs can communicate with each other to share charging status Reliability and delay has been shown to adhere to smart grid requirements
Energy Trading with EVs Mobile Energy Buffers (MEBs): EV batteries Delay-Tolerant Loads (DTLs): Dryer, washing machine, pool pump, etc. Energy Management System (EMS): Aggregator at the distribution system Token: Smallest unit of transaction Local buffers at homes and offices M.Erol-Kantarci, J.H. Sarker, H. T. Mouftah, Energy Routing in the Smart Grid for Delay-Tolerant Loads and Mobile Energy Buffers, in Proc. of IEEE Symposium on Computers and Communications (ISCC), Split, Croatia, July 7-10, 2013.
Energy Trading with EVs (cont d) Four-way handshake protocol to negotiate on seller and buyer EVs are eager to sell energy and make revenues DTLs can benefit from lower electricity rates due to EVs capability to store cheap electricity over night Substation EMS DTLs MEB
Summary ITS and Smart Grid are Smart Cities main infrastructues Charging load of PEVs impacts the grid M2M Communication-enabled load control techniques are imperative M2M Communication is also required for V2G applications Current communication technologies evolve around EV2I PLC, Zigbee, WiFi, cellular, ethernet are alternative solutions For intra-vehicle M2M communications adoption of PLC and Ethernet is emerging Future technologies will cover EV2EV communications to empower new set of applications Many open issues in the domain of applying VANETs for the benefit of EVs and the smart grid
Thank you Questions