SMART GRID - REFERENCE MODEL, CHARACTERISTICS AND IMPLEMENTATION Pavun R, Rajarajeshwari D, Electrical and Electronics Engineering, Thiruvalluvar College of Engineering and Technology, Vandavasi. Abstract-As one of the enabling technologies, a fast,

In this paper a review of some of the vulnerability

reliable and secure communication network plays a

risks that actual electric power systems face,

vital role in the power system management. The

showing some implementation issues of it are

network is required to connect the magnitude of

discussed leading to ensure a secure energy sourcing

electric devices in distributed locations and exchange

to the economy.

their status information and control instructions. The current communication capabilities of the existing

I.POWER SYSTEM COMMUNICATION

power systems are limited to small-scale local regions

With the addition of renewable energy sources, bi-

that implement basic functionalities for system

directional dynamic energy flows are observed in the

monitoring

power-line

power grid. To effectively manage this complex power

communications and the Supervisory control and

system that involves an enormous number of diversely

data acquisition (SCADA) systems, which do not

functional

yet

infrastructure is required to coordinate the distributed

and

meet

the

control,

such

demanding

as

communication

requirements for the automated and intelligent

devices,

a

co-located

communication

functions across the entire power system.

management in the next-generation electric power II.SMART GRID

systems. The Smart grid technology use increased monitoring

A smart grid is an electrical grid that uses information

and

System

and communications technology to gather and act on

accurate

information, such as information about the behaviors of

measurements and intelligent controllers. Since

suppliers and consumers, in an automated fashion to

several power control systems have been procured

improve the efficiency, reliability, economics, and

with openness requirements, cyber security threats

sustainability of the production and distribution of

become evident. Now the vulnerability of the power

electricity. In the smart grid, many distributed renewable

system is not mainly a matter of bulk power electric

energy sources will be connected into the power

system or physical system, is every day more a matter

transmission and distribution systems as integral

of Cyber security. A market participant unable to see

components.

accurately the market or a SCADA unable to control

CHARACTERISTICS

control

of

Communication

the

grid.

integrate

Power more

properly some facilities could be as disastrous as a

Self-healing

terrorist attack to some key power plants or

Motivates and includes the consumer

transmission lines.

Resists attack

Increases power quality

power grid a critical asset, and damage to it can have

Accommodates all generation and storage

devastating affects to our society's welfare. Parallels are

options

drawn between the electrical power grid and the Roman

Enables electrical markets

aqueduct system in. Over time the Roman aqueducts

Optimizes assets and operates efficiently

underwent design changes. As the Roman Empire grew,

III. THE SMART GRID WILL BE SELF-HEALING

the level of perceived threat lowered. This lead to design

This means that it can redirect and adjust the

changes that were less concerned with security and more

flow of electricity in the event that an electrical

with form and functionality. Then towards the end of the

transmission path is interrupted. This is done by a

Roman Empire these aqueducts became easy military

continuous self-assessment of the state of the power

targets for invading forces because of the design

system. As a result, this can reduce the frequency and

changes. Attacks against Roman aqueducts had major

duration of major blackouts. It is estimated that the

social impacts because they had become a critical system

August 14, 2003 blackout in the U.S. and Canada had a

that the Romans depended on. The electrical power

societal cost of $10 billion. Reducing the number of

system is a critical asset that we rely on, and it needs to

major blackouts and their severity will reduce the

be resilient to all forms of attack.

economic losses our society incurs during these blackouts.

VI.THE SMART GRID WILL PROVIDE AN INCREASE IN ELECTRICAL POWER QUALITY

IV.THE SMART GRID WILL MOTIVATE AND INCLUDE THE CUSTOMERS

Electricity is not only required to be available at all times from the power grid, but it must also maintain a

There is currently minimal interaction between

constant voltage. Some manufacturing processes are

customers and suppliers in the electrical power system.

very sensitive to voltage variations. A dip in voltage

The Smart Grid provides customers with more

lasting less than 100 milliseconds can have the same

information and options about their electrical power. In

effect as power loss for several minutes or more on some

theory this will allow customers to make better decisions

industrial processes. These voltage fluctuations are

about their power usage that will not only save them

estimated to cause productivity losses in commercial

money, but will also promote competition between

facilities ranging from thousands to millions of dollars

power suppliers. This is done by enabling two-way

per event. It is estimated that by 2011, 16% of the

communication

electrical load will require digital quality power.

between

energy

consumers

and

suppliers. The Smart Grid can also interact with

VII.THE SMART GRID WILL ACCOMMODATE ALL

electrical appliances in a customer's home. This

GENERATION AND STORAGE OPTIONS AVAILABLE

interaction allows appliances to schedule their run time

The integration of renewable energy sources into

when electricity is at the cheapest price.

the electric power grid has several complications. The

V.THE SMART GRID WILL BE RESILIENT TO

current electric power grid is a broadcast model that is

ATTACKS AND NATURAL DISASTERS

designed to only allow the one-way flow of electricity

The Smart Grid will not only be resilient to

from a one-generation source to many consumers.

physical attacks, but also cyber attacks. The electrical

Renewable energy sources are often geographically

power grid is a complicated system that is at the root of

separated from traditional power sources, and when they

most U.S. economic growth. This makes the electrical

are integrated into the power grid it is as distributed

power sources. Since the electrical power grid was

will also reduce the chance of equipment failure since

designed for only a single power source and not multiple

the degradation of equipment can be tracked. The Smart

distributed power sources, this causes complications.

Grid will also incorporate new technologies that will

Germany has experienced issues related to problems in

reduce energy loss during electrical transit. This

their electrical power grid. Customers using solar panels

reduction in energy loss will increase the electrical

could overload the electrical power system when surges

power grid's efficiency by eliminating excess power

of power come from the solar panels .Fossil fuels are not

waste.

a sustainable energy source, and as a result new

SMART GRID REFERENCE MODEL

alternative power sources will be explored. The Smart

In the smart grid, many distributed renewable energy

Grid will be able to support these new energy sources

sources will be connected into the power transmission

along with the traditional power sources.

and distribution systems as integral components.

VIII.THE SMART GRID WILL ENABLE ELECTRICAL MARKETS Electrical markets in the Smart Grid will encourage competition among power suppliers. This competition will promote power suppliers to develop cheaper and more efficient means of power generation. This will drive down the prices of electrical power for customers as suppliers compete for their business. The Smart Grid will also support distributed power sources. This opens the door for new electrical power suppliers and electrical service providers to enter the electrical market. The electrical market will broadcast current electricity prices based on a supply-demand model. Electricity will be more expensive when the load or demand is high, and it will be cheaper when there is surplus electricity. Customers can use this information to schedule tasks that use large amounts of electricity at a time when electricity is cheaper.

BULK GENERATION Electricity is generated by using resources like oil, coal, nuclear emission, flowing water, sunlight, wind, tide, etc. This domain may also store electricity to manage the variability of renewable resources such that the surplus electricity generated at times of resource richness can be stored up for redistribution at times of resource scarcity. The bulk generation domain is connected to the transmission domain. It also communicates with the market domain through a market services interface over Internet and with the operations domain over the wide area network. It is required to communicate key parameters like generation capacity and scarcity to the other domains.

IX.THE SMART GRID WILL OPTIMIZE ASSETS AND OPERATE EFFICIENTLY

The

The features that will make the Smart Grid selfhealing can also be used for asset management. The Smart Grid will be able to automatically assess equipment

condition

and

manage

TRANSMISSION

equipment

configuration. This management automation can be done at substantially lower costs compared to manual management. The automation of equipment management

generated

electricity

is

transmitted

to

the

distribution domain via multiple substations and transmission lines. The transmission is typically operated and managed by a RTO or an ISO. The RTO is responsible for maintaining the stability of regional transmission lines by balancing between the demand and supply. The transmission domain may also support small

scale energy generation and storage. To achieve selfhealing functions and enhance wide area situational awareness and control, a lot of information will be captured from the grid and sent to the control centers. The control centers will also send responses to the devices in remote substations. DISTRIBUTION The dispatch of electricity to end users in the customer domain is implemented by making use of the electrical and communication infrastructures that connect the

Distributed functions across entire power system MARKET

transmission and customer domains. This domain includes distribution feeders and transformers to supply

This domain

electricity. It interacts with much different equipment,

electricity

such as DERs and sensors with communication

electricity, traders who buy electricity from suppliers

capability.

and sell it to retailers, and aggregates who combine smaller

OPERATION

to

consists

of

retailers

end users,

DER

supply

of

bulk

suppliers

resources between

who

for

bulk

Effective

This domain maintains efficient and optimal operations

communications

of the transmission and distribution domains using an

electricity, the DERs and the market is essential to match

EMS in the transmission domain and a DMS in the

the production of electricity with its demand.

producers

of

CUSTOMER

distribution domain. It uses held area and wide area networks in the transmission and distribution

the

sale.

Customers consume, generate (using DERs), or

domains.

An illustrative framework of next-generation power grid,

store

electricity.

This

domain

includes

home,

where A is a wind power plant, B is a large hydro power

commercial or industrial buildings. It is electrically

plant, C is a coal-?re power plant, D is a geothermal

connected to the distribution domain and communicates

power plant, E and F are houses with solar-electricity

with the distribution, operation, service provider and

generation, G and H are houses with wind-electricity

market domains. The customer domain also supports the

generation, I is the power transmission infrastructure, J

demand response process.

is the communication infrastructure, and K–Q are the

SERVICE PROVIDER

seven constituent domains that are bulk generation,

Service providers manage services like billing and

transmission, distribution, operation, market, customer,

customer account management for utility companies. It

and service provider, respectively information of the

communicates with the operation domain to get the

power system activities like monitoring, control, fault

metering information and for situational awareness and

management, maintenance, analysis and metering.

system control. It must also communicate with HANs in the customer domain through the ESI interface to provide smart services like management of energy uses and home energy generation.

X.OPEN COMMUNICATION SYSTEMS

VULNERABILITIES

Open communication systems are used extensively

Although effective attack responses will become

because

important for the continued operation of the grid, the

1. Hardware and software are relatively inexpensive

mitigation of grid cyber security vulnerabilities remains

2. Installation relies on familiar tools and techniques

critical and is a responsibility of manufacturers, utilities,

3. Existing communications infrastructure can often be

and

used

increasingly require the electric sector to protect its IT

4. Open protocols cut integration costs

and telecommunications infrastructure As the grid

5. Qualified personnel are widely available

modernizes, the growing prevalence of information and

First, open systems cut purchase costs because

communications technology in the system and the large

communications hardware and software based on

numbers of personnel with access to it will create an

Ethernet and the Internet are much less expensive than

ever-evolving cyber security situation, where the relative

their proprietary alternatives.

importance

Second, installation is eased because of a widespread

continuously as new types of attacks emerge. In

familiarity with these types

particular, the introduction of the Internet to grid

of

systems

among

the

government.

of

Achieving

specific

this

vulnerabilities

task

will

changes

contractors.

operations has introduced additional vulnerabilities to

Third, existing communications infrastructure can be

the power system, especially where corresponding

used in many cases, dramatically reducing installation

security controls have not been put in place. Cyber

and other related costs.

security vulnerabilities can arise from weaknesses in

Fourth, integration expenses for connecting different

personnel, processes, technology, and the physical

smart grid components are reduced because Ethernet is

environment. Security issues occur because of actions

used as a common communications hardware protocol.

taken by outside hackers and attackers, and also by

Fifth and last, on-going maintenance and operation costs

disgruntled employees. With their insider knowledge,

are reduced because many in the industry are familiar

these individuals may instigate significant damage.

with Ethernet and the Internet.

Open System Vulnerabilities

Open communication systems are a necessity because

The vulnerabilities are caused by

they keep costs down, but as the name implies these

1. Large number of interconnections creates multiple

systems are much more vulnerable to cyber attack than

vulnerabilities

their

2. Armies of professional hackers are familiar with open

proprietary

and

more

closed

alternatives.

Proprietary systems not only have fewer connections to

system protocols

other systems, they are also less familiar to professional

3. Browser-based Internet servers and clients create

hackers, creating a possible ―security through obscurity‖

entry points

defense. On the other hand—communication systems

4. Windows-based systems invite attack

based on Ethernet, TCP/IP protocols, the Internet and

5. Vulnerable TCP/IP software stacks are used across

widely used operating systems such as Windows invite

multiple platforms

attack from literally millions of hackers worldwide.

6. Older closed protocols lack security when ported to open protocols like TCP/IP

Cyber security issues

Also some breakers, switch gears and pumps have its own connections and can be managed through telephone lines. Many power plants and substations have many modems, being another easy target to hackers. Hackers find these modems dialing phone numbers sequentially and once they are connected they can map the system and spy for passwords. More secure systems use dial back modems (they respond to a password by dialing a confidential phone number for confirmation) this system are hacked by trying sequentially different passwords. Nowadays many field devices, designed to do specific tasks are still based on low cost micro processor such as Intel 8088 and they can’t run encrypted authentication

Categories of cyber threats to power system

schemes fast.

XI.SCADA SYSTEM AND SCADA SECURITY Application of conventional network security measures work well in IT environment, but it is not always possible to implement in industrial control systems. These systems assume that devices are competent to answer a password and identify it, but most PLCs can’t answer passwords. The problem is that PLCs and SCADA systems were designed without security in

PROTOCOL ATTACKS The protocols used in the power system, such as ICCP, IEC 61850, DNP3, could be potentially exploited to launch cyber attacks if they are not secured properly. This calls for secure versions of these protocols that not only provide security guarantees, but also the required latency and reliability guarantees needed by the grid applications.

mind. Designers implicitly assumed that these systems would be isolated, no connected to other systems, and also assumed that only authorized people would have access to the system, and it is not a good assumption today. The fact is that every day more and more employees have been replaced by automated controls at substations, pipelines, etc., and now thousands of these facilities are being controlled by SCADA systems linked to networks. Nowadays, many SCADA systems carry some data through Internet in order to avoid more expensive private lines. In addition to this, almost all RTU’s (Remote Terminal Units that coordinate a facility’s automated field devices) or control systems are Web or Network enabled and often times we use these features.

ROUTING ATTACKS This refers to cyber attack on the routing infrastructure of the Internet. Although this attack is not directly related to the operation of the grid, a massive routing attack could have consequences on some of the power system applications, such as real- time markets, that rely on them. INTRUSIONS Wireless systems are especially vulnerable to attacks. Some people use these systems in their networks and feel secure because they think firewall would protect them from unauthorized access, and therefore some people don’t use security features of the wireless equipment. In fact, if you are close to a wireless system and you have a directional antenna such as Pringles Antenna (look at Google to know how to build an

antenna with a can of Pringles), you can go into the

perceived as a source of concern in recent years as

network without need to overcome the firewall.

identified in many federal documents.

Wireless security standards are easily defeated, wireless

XII.CYBER SECURITY

transmitters use IEEE 802.11b and it has serious security

Cyber security must address deliberate attacks such as

flaws. Simply using free software, such as AirSnort and

internal breaches, industrial espionage and terrorist

NetStumbler, a hacker can have enough tools to crack

strikes—as well as inadvertent compromises of the

wireless codes within 15 minutes. After they get the

information infrastructure due to user errors, equipment

wireless encryption key, they can use a freebie protocol

failures and natural disasters.

analyzer like Ethereal or Sniffit to spy on the network.

OBJECTIVES

At this point, they can see people login into different

Availability. Availability is the most important security

equipment's

Logic

objective. The availability of the electrical power grid is

Controllers PLC), and since people tend to repeat

its most important factor. The critical real-time systems

passwords, they probably could log into other PLCs and

in the Smart Grid have an estimated maximum latency

network.

of 4 milliseconds. These systems continuously monitor

(for

example

Programmable

MALWARE This

refers

to

malicious

software

the state of the electrical power grid, and a disruption in that

exploits

communications can cause a loss of power.

vulnerabilities in system software, programmable logic controllers, or protocols. The malware generally scans

Integrity. Integrity is the next important security

the network for potential victim machines, exploits

objective in the Smart Grid. The Smart Grid uses data

specific vulnerabilities in those machines, replicates the

collected by various sensors and agents. This data is

malware payload to the victims, and then self-

used to monitor the current state of the electrical power

propagation. In recent years, malware attacks are

system. The integrity of this data is very important.

growing in numbers and sophistication, and this has

Unauthorized modification of the data, or insertion of

been a source of major concern for critical infrastructure

data from unknown sources can cause failures or damage

systems (e.g., Stuxnet) including the power grid.

in the electrical power system. The electricity in the

DENIAL OF SERVICE ATTACKS

power grid not only needs to always be available, but it

Any attack that denies normal services to legitimate

also has to have quality. The quality of the electrical

users is often called denial of service. This could also

power will be dependent on the quality of the current

mean denial of control in the power grid context. These

state estimation in the power system. The quality of the

attacks are typically created through massive resource

state estimation will rely on many factors, but integrity

exhaustion attacks that flood the communication

of input data is very important.

network or the server with huge volumes of traffic or

Confidentiality.

spurious workloads, thus denying service to legitimate

confidentiality. The loss of data confidentiality in the

users.

Smart Grid has a lower risk than loss of availability or

The

final

security

objective

is

INSIDER THREATS

integrity. There are certain areas in the Smart Grid where

An insider abuses their current system privileges to

confidentiality is more important. The privacy of

perform a malicious action. This form of threat is

customer information, general corporation information, and electric market information are some examples

XIII.STEPS TO CYBER SECURITY

storage media. Eliminating these types of elementary

1. Understand existing regulatory requirements

errors will go a long way towards improving cyber

2. Understand the nature of cyber threats

security.

3. Identify non-compliance areas and vulnerabilities

The fifth step is to install hardware and software that

4.

will protect against cyber attacks. For existing systems,

Create

and

enforce

company-wide

security

procedures

retrofits and replacement of components on a selective

5. Install hardware and software to ensure compliance

basis is the common path. For new substations and other

and protect vulnerabilities

facilities, systems can be designed from the ground up

6. Continuously monitor as technology and regulations

with cyber security in mind.

evolve

ACTIONS DENIAL-OF-SERVICE DEFENSE.

Cyber security must address deliberate attacks such as

All the information availability attacks interfere with

internal breaches, industrial espionage and terrorist

the normal information exchanges by injecting false

strikes—as well as inadvertent compromises of the

or useless packets into the communication networks. The

information infrastructure due to user errors, equipment

false information confuses the packet recipients in

failures and natural disasters.

recognizing the correct information. The useless packets

As outlined, there are six steps to protect utility T&D

consume a significant share of network bandwidth such

systems from cyber threats. The first is understanding

that the legitimate traffic is knocked out in the network.

regulatory requirements. Industry seminars can help, as

Both types of attacks deny the information availability in

can good consultants and the right suppliers. Discussions

the communication networks. Solutions to defend

with peers at industry events are also a good way to

against the denial-of-service attacks rely on a careful

glean information about the most relevant aspects of

discretion of the legitimate traffic from the attack traffic.

regulation.

An effective solution must be able to filter out the attack

Much of the same information gathering path can be

traffic to protect the legitimate information exchanges.

taken towards the second step: understanding the nature

INTEGRITY PROTECTION

of cyber threats. As outlined in the sidebar, SCADA

To prevent messages from unauthorized changes during

Systems and Cyber Attacks, threats are now expanding

transmission, mechanisms are needed for the message

from attacks on general purpose computer systems to

recipients to verify the originality of the received

attacks on hardware and software platforms commonly

messages. The integrity protection solutions rely on the

used to perform real-time control and monitoring of

established agreements between message senders and

power systems.

receivers on the use of message encryption keys. The

The third step is to identify areas of non-compliance and

message senders use the encryption keys to compute a

vulnerabilities. This is most often accomplished by a

message digest for each message and the message

system audit, typically by engaging a technical services

receivers use the corresponding decryption keys to verify

firm specializing in this area of SCADA security.

the correctness of the received message digest. The

The fourth step is to create and enforce

encryption and decryption keys can be either identical or

company-wide security procedures. A large percentage

asymmetric.

Usually

identical

keys

have

lower

of security breaches are caused by simple mistakes such

computational over- head than asymmetric keys. In order

as poor password selection or use of unauthorized

to establish the encryption and decryption key pairs, key

exchange protocols must be completed before the message integrity can be protected.

IMPLEMENTATION ISSUES The first issue with the implementation of these

XIV.AUTHENTICITY ENFORCEMENT

standards is the higher cost. To increase the security

Message origins must be verified in the power system

standards in the system brings higher operational costs

communication networks

sophisticated

and also requires important investments. To start a new

attackers from impersonating legitimate power devices

program of considerable investment in a company that

to transmit forged messages. The solutions to guarantee

operates in the market requires many months, semesters

message authenticity are built on top of the mechanisms

or a year, in order to include this program in the

that require message senders prove their identities. The

investment budget of the next year (more equipment,

identity proofs are usually presented in the form of

software, personnel, etc., usually require share holder

demonstrating the knowledge of certain secrets that are

approval).

known by the message senders. The secrets used for

The second issue is the implementation of a transition

identification are usually the same message encryption

period, where companies that are currently not

keys used for integrity, protection and therefore the

accomplishing the standards are allowed to keep

authenticity enforcement schemes employ either the

operating in the market without penalty in order to give

symmetric or the asymmetric encryption and decryption

them a reasonable time to improve their security

key pairs. Key exchange protocols are necessary in order

standards. Once this period is finished the companies

to establish the key pairs.

that are not accomplishing the standards should not be

to prevent

SECURITY POLICIES

allowed to keep working in the electric market because

Password policy

they represent a risk for the whole power system.

Periodic changing of passwords,

Other issue emerges when different market participants

Replacement of default passwords on newly

merge in one, and they have very different cyber security

installed equipment.

systems and procedures and they may not be easily

Identification and Authentication of Users

merged with the ones of the preexisting company. The

Periodic review of computer accounts and

lack of transparency or a small delay in process a

access rights.

requirement of data can produce a problem of

Disabling of unauthorized accounts.

asymmetric information, since information is valuable

Secure E--mail protocols.

not only for market participants but also for the whole

Intrusion detection.

market. Every day the automated systems are moving

Disabling of unused network services and ports.

toward more open architecture, potentially increasing

Secure modem connections.

security vulnerabilities.

Firewall software.

CONCLUSION

Install updated anti-virus software's.

The development of an attack resilient electric grid

System Backup and Recovery plan.

is necessary to address increasing concerns to the

Operator logs, application logs, and intrusion detection

security of the nation’s critical infrastructure. As

logs shall be maintained as appropriate for the purpose

cyber attacks become more prevalent, attackers are

of checking system anomalies and for evidence of

expanding their focus to address industrial control

suspected unauthorized activity.

system environments, such as the electric grid.

Additionally,

the

deployment

of

smart

grid

technologies expand the grid becomes increasingly dependent

on ICT

for

control

and

monitoring

functions which introduces greater exposure to cyber attack. The development of an attack resilient electric requires substantial research efforts, which explore methods to create a secure supporting infrastructure along

with

robust

power

applications.

The

developing of a secure cyber infrastructure will limit an attacker’s ability to gain unauthorized access

to

security

critical

grid

resources.

Infrastructure

enhancements require the expansion and

tailoring of current cyber protection mechanisms such as authentication, encryption, access control, and intrusion

detection

systems.

Unfortunately

infrastructure level protection mechanisms may not prevent all cyber attacks. The development of more robust control applications will ensure the grid can still operate reliably during an attack by leveraging information about expected system states and operating conditions. REFERENCES. [1]. Bloom Energy (http://electronicsforu.com/electronicsforu/circuitarchives/view_article.asp?s no=1832#.U-yFnWPYCQ&title%20=%20Bloom+Energy%3A+Another+Renewable+Energy+Sour ce&b_type=new&id=13118&group_type= ) [2]. India Survey: Power Shortage May Worsen (― http://online.wsj.com/news/articles/SB10001424127887324662404578329783 138937470 :) th [1] Bimbhra, P.S: Electrical Machinery, 7 ed., Khann Publishers, New Delhi, 2005. pp. 544-.

[2] Specification for 25 KW brushless alternator with rectifier cum regulator equipment for 110 volt DC SG AC coaches, Power supply and EMU directorate, Research Designs and Standards

[3] Iqbal Tariq , Three Phase Power Regulator, Electronic World, August 2000