Life Long Learning Aalborg University By Kartheepan Balachandran kba@es.aau.dk

What thoughts we had for the course Like to have feed back afterwards

Would like to make the course interactive so

we avoid this ->

Communication network in smart grid Communication standards Use of existing technologies & research stuff Break Reliability in smart grid Research project: smartc2net Security and privacy

*5 minutes break inbetween each subject

What is Network? People take network for granted, WHY?

Bi-Directional flow of electricity and information

http://venturebeat.com/2010/12/08/smartgrid-europe-renewables/

Wide Area Network Field Area Networks

▪ (Field and Costumer application)

Home Area Networks

Connecting distributed small area networks A form of communicaiton backbone Gets data from Phasor Measuring Unites

(PMU) Transport SCADA data to control center Requirement

Data transfer within the frequency of sampling of the phasor data (PMU)

High bandwidth , low latency

Field based application

Supervisory Control and Data Aqusition (SCADA)

Distributed Energy Resources (DER) monitoring and control

Requirement

Realtime monitoring - Time sensitive

Dedicated network is good but costly

▪ Gives additional security

Costumer based application

Advanced metering Infrastructure (AMI)

Demand Response (DR)

Requirement

Highly scalable network

Time sensitive is not an issue

Doesn’t require a dedicated network

▪ Security has to be implemented

Customer domain:

Monitoring and control of smart devices

Demand Response

Realtime pricing (RTP)

Requirement

Secure two-way communication

Utility public broadcast for event and price signals

Use the internet? Pros: Already deployed

Cons: Reliability?

Deploy dedicated network? Maybe partially? Pros: Secure reliable network Cons: Very costly

What technology do we use? Power line, Wired or Wireless? Maybe a hybrid?

How do we know what technology to use? How do we define requirements for a network? How do we define Performance? What metrics do we use to measure and evaluate

the performance of a network?

Bandwidth

Latency

Jitter

Scalability , availability, QoS

Consequence of low bandwidth? Bottle neck

High delay

Packet loss

Wide area network requires Bandwidth

It act as a backbone network to connect all small area networks

Have to transfer large amount of data

Data collection from PMU’s

Case study:

If I have 10 Mbit internet connection, will I be able to deliver the data needed for smart grid?

Keyword: Delivery

Truck analogy

▪ Is it okay if I use a truck to send 1000 memory sticks of 2 MB of data to france but it will take 2 days to be received?

▪ Or do we prefer to send 2GB in less time?

IP over Avian Carriers ▪ Proposal to carry IP traffic by birds eg. Homing pegeons.

▪ RFC 1149 by D. Waitzman 1 april 1990

▪ Later improved the protocol with RFC 2549 IP over Avian Carriers with QoS

IPoAC has been successfully implemented, but for only nine packets of data, with a packet loss ratio of 55% (due to user error),[2] and a response time ranging from 3000 seconds (~54 minutes) to over 6000 seconds (~1.77 hours). Thus, this technology suffers from poor latency. Nevertheless, for large transfers, avian carriers are capable of high average throughput when carrying flash memory devices

Source: http://en.wikipedia.org/wiki/IP_over_Avian_Carriers#cite_note-1

The time it takes a packet to reach its destination and get back an acknowledgement (depending on the protocol)

The communication between the customer and the utility company is not time sensitive

Measuring the grid status require realtime data and require therefore low latency

Spikes in routing/switching delay Jitter can give spikes of latency Eg. caused by bittorrent which opens many

communication channels and thereby overload the routers scheduling mechanism

Gives data loss which can be experienced in phone conversation.

Not good for real time application

Prioritisation of traffic ISP setup QoS on router for VoIP service QoS might also be necessary if we want to use

the internet to send meter data or do Direct load control at the Customer.

Reliability Network must not go down

Delay sensitive Time sensitive data must be able to reach

destination Security

The network must be resilient against attacks and manipulation and ensure privacy

Cost efficient Must not be costly to deploy the network

Requirement Have to understand the problem to be able to set up

requirements

Understanding delay components The network will consist of many different network

tech. And components which introduce different delays in the system

Minimizing end-to-end delay Network tech. Selection and protocol development to

speed up time urgent messages.

In the end we want to avoid this from many point of views:

Standardisation activities

Guides for development of next generation electric power systems.

The ”famous” standards

▪ IEC Standards

▪ IEEE Standards

▪ ANSI

IEC - International Electrotechnical Commission IEEE - Institute of Electrical and Electronics Engineers ANSI - American National Standards Institute

IEC 61968-9 and 61970 (energy man. Syst.)

▪ Defines the common information model for data exchange between devices and networks in the power distribution domain and the power transmission domain respectively.

IEC 62351 (information security)

▪ Defines the requirements to achieve different security objectives including data authentication, data confidentiality, access control and intrusion detection.

IEC 60870-6 (Inter-control center communiation)

▪ Data exchange between utility control center, utilities, power pools, regional control centers.

Source: W. Wang et al. / Computer Networks 55 (2011) 3604–3629 GÜNGÖR et al.: Smart grid technologies: communication technologies and standards

IEC 61850 (appl. Substation automation):

▪ Defines the communication between devices in transmission, distribution and substation automation systems.

Source: W. Wang et al. / Computer Networks 55 (2011) 3604–3629

IEEE P2030 (Customer side appl.)

▪ A guide for smart grid inter-operability of energy technology and IT operation with the electric power system.

IEEE P1901 (Home area network)

▪ High pseed power line communication for in-home multimedia, utility and smart grid application

IEEE 1547 (Field area network for D.E.R)

▪ Defines and specifies the electric power system that interconnects distributed resources.

Source: W. Wang et al. / Computer Networks 55 (2011) 3604–3629 GÜNGÖR et al.: Smart grid technologies: communication technologies and standards

IEEE 1646 (substation automation)

▪ Defines communication delivery times to substation. It also discuss the system and communcation capabilities required to deliver real-time support, message priority, data critcality and system interfaces.

Laverty, D.M. et al.: Practical evaluation of telecoms for Smart Grid measurements, control and protection

Source: GÜNGÖR et al.: Smart grid technologies: communication technologies and standards

ADSL WiMAX 3G/LTE FTTH GSM PLC

Two types of medium can be used, eg.

Wireles and wired.

Two types of information infrastructure are needed for information flow in smart grid system.

1. From sensor and electrical appliances to smart meters

2. From smart meters to the utility’s data centers.

From sensor to smart meter can be achieved by e.g.: PLC

▪ Advantage: Existing infrastructure, cost-effective, already used in HAN. ▪ Disadvantage: transmission are broadcasting, critical from security

aspect, the medium is noisy, effected by number and type of devices connected to the powerline, wiring distance between transmitter and receiver affect the quality of the transmitted signal.

ZigBee ▪ Advantage: Low power, range from 1-100m, low cost deployment and

standardized protocol IEEE 802.15.4

▪ Disadvantage:low processing capabilities, small memory size, subject to interference (2.4 Ghz), can be easily currupted by WiFI, Bluetooth and Microwave

Source: GÜNGÖR et al.: Smart grid technologies: communication technologies and standards

To send data from smart meter to data centers Cellular technologies

▪ Advantage: GSM, GPRS, UMTS, WiMAX, 3G, LTE already exist. No extra cost to build infrastructure. Widespread cost-effective benefits. Can reach rural areas. Low maintenance cost

▪ Disadvantage: power grid mission-critical applications need continuous availability of communication. The cellular networks are shared by customer market. Network congestion or decrease in performance can happen.

DSL

▪ Advantages: widespread availability, low-cost and high bandwidth data transmissions.

▪ Disadvantages: Reliability and potential down time may not be acceptable. Not reachable on rural areas due to high deployment cost

Source: GÜNGÖR et al.: Smart grid technologies: communication technologies and standards

Source: GÜNGÖR et al.: Smart grid technologies: communication technologies and standards

Laverty, D.M. et al.: Practical evaluation of telecoms for Smart Grid measurements, control and protection

Smart Grid Net simulator Reliable choice of Aggregator for connecting

Electric Vehicle to the Smart Grid

The metadology approach is building a smart grid simulator

We want to enhance a network simulator with smart grid communication features

Analysis of a specific usecase

Lookup for potential

aggregators

Fetch information

and decide on aggregator

Connect to aggregator

Waiting time (tw)

Delay 2 Delay 1 Aggregator1

Aggregator2

Aggregator3

DER

X

X

X X

X

X

X

Model: -Stationary processes

-Indepence and identic

distributed

Key parameters that impacts reliability

- Event interarrival times

- Communication delay btw. Aggregators and DER’s

- Waiting time

Aggregator 1 (Avg): Delay 70 ms,

Event time 78 sec.

Aggregator 2 (Avg) Delay 50 ms

Event time 18 sec.

Aggregator 3 (Avg) Delay 531 ms

Event time 20 sec.

Aggregator 4 (Avg) Delay 829 ms

Event time 92 sec.

Aggregator 5 (Avg) Delay 732 ms

Event time 25 sec.

How long shall we wait?

Optimal waiting time