HIERARCHICAL COMMUNICATIONS INFRASTRUCTURE IN SMART GRIDXiaoxia Zhangx79zhang@bbcr.uwaterloo.ca

OUTLINE Cognitive Radio Based Hierarchical

Communications Infrastructure for Smart Grid Hierarchical communciation structure Challenges on the design of communication

architecture Cognitive radio based architecture

Reliable Overlay Topology Design for the Smart Microgrid Network

Microgrid Smart microgrid Overlay topology design for smart microgrid networks

Cognitive Radio Based Hierarchical Communications Infrastructure for Smart Grid

HIERARCHICAL STRUCTURE

HIERARCHICAL STRUCTURE Home area network (HAN) - communicate with various smart devices to

provide energy efficiency management and demand response

Neighborhood area network (NAN) - connect multiple HANs to local access point Wide area network (WAN) - provide communication links between NANs

and the utility systems to transfer information

CHALLENGES ON THE DESIGN OF COMMUNICATION ARCHITECTURE Tremendous data amount - explosive growth of data gathered by smart meters and sensors - utilities handle 10,780 Tbytes in 2010, 75,200 Tbytes in 2015 Energy sources - balance utility source and renewable energy sources Highly varying traffic - peak hour requires high data rate and more reliable services Interoperability - ensure operation among generation, transmission, distribution and

user networks Quality of service - meter data needs higher priority and QoS, while price data needs

normal priority and QoS Security - computer networks for controlling and monitoring, exposed to attacks

COGNITIVE RADIO BASED ARCHITECTURE Motivations:

Increasingly intensive radio systems in HAN. CR improves spectrum utilization and

communication capacity to deal with large amount of data.

CR devices could manage context awareness to enable the realization of the heterogeneous network.

COGNITIVE RADIO BASED ARCHITECTURE

COGNITIVE RADIO BASED HAN HGW: cognitive home gateway used to

transmit data and manage spectrum band. Two components: spectrum access controller

and power coordinator.

COGNITIVE RADIO BASED NAN NGW allocates spectrum bands to HGWs. Guard channel strategy: some reserved channels for

handoff for both PUs and SUs to guarantee QoS. Pd: dropping prob. Pb: blocking prob. NG: guard channal NC: common channel

COGNITIVE RADIO BASED WAN/NAN A WAN has K NANs.

Reliable Overlay Topology Design for the Smart Microgrid Network

MICROGRID Small-scale, self-contained medium/low power system. Distributed generators (DG), controllable loads, small-

scale combined heat and power units (CHP) and distributed storage (DS).

Two operation modes: grid-conected and islanded.

SMART MICROGRID Less transmission loss and less cable loss Reduce carbon emission Fault isolation in case of a failure or attack Ease of DG handling Energy trading among microgrids (future) SMGs can form a network SMGN to maximize

the utilization of renewable energy resources.

OVERLAY TOPOLOGY DESIGN FOR SMGN Target survivability (stay in working condition in

case of a failure) utilization of the renewable resources more

effectively

Method Form clusters in a SMGN

OVERLAY TOPOLOGY DESIGN FOR SMGN Step1: Cluster SMGs. SMGN: G(t)={V,E(t)} where V is the set of

SMG and E(t) is set of logical links among SMGs. |V|=N.

Link between two SMGs (u,v)€E(t) means u and v can share the storage bank.

is binary, 1 if and only if SMG i and SMG j are on the same cluster.

Survivability for Cluster r

OVERLAY TOPOLOGY DESIGN FOR SMGN Step2: Find a Hamiltonian cycle in each

cluster.

SIMULATION RESULT

Questions and Discussion?

Thank you!

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