SMART METERING AND

CONTROL OF TRANSMISSION

SYSTEMBY

M.SAI MANOBHIRAM

G.DURGA RAO

D.MOHITH

“Smart Grids”

“A smart grid uses digital technology to improve reliability, security, and efficiency (both economic and energy) of the electric system from large generation, through the delivery systems to electricity consumers and a growing number of distributed-generation and storage resources.”

Characteristics of Smart Grid

Self-healing

Motivates and includes the consumer

Increases power quality

Accommodates all generation and storage

options

Enables electrical markets

Optimizes assets and operates efficiently

SMART GRID vs EXISTING SYSTEM

Existing

• Not self healing

• Does not allow integration of

sources

• Real time data is not available

• Slow and manual

• Mostly involves analog functions

smart grid

• Self healing

• Smart grid is designed

to integrate sources

• Real time data is

available

• Fast and automatic

• A complete digital

system

SMART GRID INCLUDES:

• Integrated communications

• Sensing and measurement

• Smart meters

• Superconductive wires

• Storage devices

• Wireless communication

ADVANTAGES OF SMART GRID

TECHNOLOGY:

• Peak Leveling

• Self-Healing

• More Reliable Power

• More Efficient Renewable Power

• A Cleaner Mix of Energy Sources

• Reducing our carbon Footprints

Disadvantages of smart grid

technology:

Security and privacy cost.

Two way communications can be

hacked.

Technology components are expensive.

Present Infrastructure is inadequate and

requires augmentation to support the

growth of Smart Grids.

Challenges in adopting smart grid:

Costly

Complicated structure

Gain control of meters

Security and privacy

Hacker

Power theft

Smart Metering Infrastructure

SMI is the totality of the systems and networks that

are used to measure, collect, store, analyse, and

use energy usage data.

In other words, SMI includes smart meters and all

other infrastructure components—hardware,

software, and communication networks that are

needed to offer advanced capabilities.

A typical SMI network employs a two-way

communication system and smart metering

technology.

SMI also uses the same system equipment to

send information back through the network to

meters to capture additional data, control the

meters, or update the meters’ firmware.

Major System components of SMI

A SMI system is comprised of a number of

technologies and applications that have been

integrated into one solution. The four major SMI

components are:

• Smart meters

• Communication system

• Meter data management systems (MDMS)

• Home area networks (HAN)

Smart Meters

The measurements from both electromechanical meters

and non-smart digital meters are collected manually by

physical site visits and, thus, record only the readings at

the time of the visit.

Smart meters are intelligent, solid-state, programmable

devices that can perform many functions beyond

energy consumption recordings.

By using built-in memories, smart meters can record and

store readings at present intervals (e.g., 15 min, 30 min, or

hourly) and prescheduled times.

Typical smart meter functionalities include the following:

i. Record interval (daily, hourly, or sub hourly) energy

consumption and demand data

ii. Provide bidirectional metering, which will

accommodate distributed generations at customer

sites

iii. Provide notification on loss of power and service

restoration

iv. Provide tamper alarms and enable theft detection

v. Provide voltage measurement, voltage alarms, and

power quality monitoring

Enable TOU rate billing

Protect meter data security

Communicate and interact with intelligent appliances or

devices in a customer’s locality

Smart Meter Communications

Smart Meter communicates with the base station or the

control centre on a bi-directional mode.

Some of the important channels that are available in

India for communication are: GSM, Wi-Fi, PLCC, PSTN,etc

The type of communication available depends severely

on the geographic location. Thus the communication

mode used should be a combination of available

options.

Here we present a brief description of technology and

viability in Indian context.

PLCC

PLCC – Power Line Carrier Communication.

As the name indicates PLCC associates the use of power

conductor for communication by imposing a modulated

carrier frequency signal over them.

They are the prime modes of communication between

substation in power sector.

The carrier signal degrades gradually along the length of

the line. So public repeaters are used which improve the

strength of the signal by demodulation and re-

modulation

Zigbee

Zigbee is the only standard based wireless technology

designed to address the unique needs of low cost low

power wireless sensor and control networks.

The technology specified by short distance data

transmission.

It operates in the region of 2.4GHz

This bandwidth is enough for the implementation of SMI

and home automation

It is faster response than any other type of

communication

It can be made to work in 3 modes

Coordinator: It forms the basic root of the system. It has

the capability to communicate with any other node

connected to network. It can even acts as a bridge

between two networks.

Router: As the name indicates it indicates like a route

decider. It routes the data based on address information

received and pass it to respective destination

End Device: It has very limited functionality of just

communicating with the network co-ordinator.

Wi-Fi

Operating in the unlicensed 2.4GHz ISM band.

It involves broadcast and reception of data through

radio signals in an encrypted format and its advantage

is it cut the cost of the cables.

The main advantage of this over Zigbee is it can be used

for the communications over the range of 1-10KM

Proposed Communication

architecture

Nodes 1-7 represent the customers or the meters associated with them.

The nodes or meters are connected to main module placed at distribution transformer through Zigbee

As the ordinary meter transmits data of nearly 34MB per month. Based on memory it transfers it will be charged.

As the range of Zigbee is less the distance between Distribution transformer and nearest residential customer ranges from 10-50m

The data collected at various distribution trsnformer is sent to its parent substation through WiFi network as the distance varies from 1-10KM

The backbone of the Smart Grid will be its network.

This network will connect the different components of the Smart Grid

together, and allow two-way communication between them.

Net- working the components together will introduce security risks

into the system.

The number of entry points that can be used to gain access to the

electrical power system will increase when all of the components

are networked together.

Cyber security

Cyber security is a concept that has become increasingly prevalent

with the development of the smart grid technology with the

increased use of digital information and controls technology to improve reliability, security, efficiency of the electric grid and the

deployment of smart technologies (real - time, automated,

interactive technologies that optimize the physical operation of

appliances and consumer devices) for metering, communications

concerning grid operations and status, and distribution automation.

Problems Occurred Due to Lack Of

Cyber Security In 2001, hackers penetrated the California Independent System Operator, which

oversees most of the State’s electricity transmission grid; attacks were routed through California, Oklahoma, and China.

Ohio’s Davis-Besse (Oak Harbor, Ohio, the United States )nuclear power plant safety monitoring system was offline for five (5) hours due to the Slammer worm in January 2003.

In March 2005, security consultants within the electric industry reported that

hackers were targeting the U.S. electric power grid and had gained access to

U.S. utilities electronic control systems.

In April 2009, the Wall Street Journal reported that spies hacked into the U.S. electric grid and left behind computer programs that could allow them to disrupt service. Associated Press on August 4, 2010 reported “Hackers Try to Take overPower Plants.” In September 2010, cyber experts discovered for the first time a malicious computer code, called a worm, specifically created to take over systems that control the inner workings of industrial plants.

Worm

A worm is a small piece of software that uses security holes within

networks to replicate itself. The worm scans the network for another

computer that has a specific security hole. It copies itself to the new machine exploiting the security hole, and then starts replicating

from that system as well. Once infected, the worm may send itself to

everyone in your address book. Using a network in this manner,

worms expand extremely quickly. The greatest danger from worms is

that they will eventually use all the memory available to a computer

or a network.

The Stuxnet Worm was reported in an Industrial Control Systems

Cyber Emergency Response Team Advisory on September 29, 2010.

Stuxnet is a Malware Targeting Siemens Control Software. It can be used to infiltrate industrial control systems used in the power grid,

power plants and other infrastructure. It is reported to have the

ability to damage or possibly destroy control systems.

The North American Electric Reliability Corporation (NERC) and

DOE released a report titled High-Impact, Low-Frequency Event Risk

to the North American Bulk Power System (June 2, 2010)16 that

identifies a certain class of high-impact, low-frequency risk shown to

have the potential to significantly affect the reliability of the North American bulk power system..

Cyber Security includes

Availability

Integrity

Confidentiality

Availability

Availability refers to ensuring timely and reliable access to

information, which is the primary security goal of a smart-grid

metering and control system. Malicious attacks targeting availability can be considered as denial-of-service attacks, which intend to

delay, block, or even corrupt the communication in the system.

The jamming attack is able to defer the transmission of messages

and to distort the transmitted data signal. As a result, the legitimate

receiver cannot recover messages out of the damaged data packets.

On the other hand, many man-in-the-middle attacks can be

launched only when the full or partial communication channels can

be jammed.

Integrity

Integrity refers to preventing or detecting the modification or

destruction of information by unauthorized persons or systems.

Malicious attacks targeting the integrity of a smart grid attempt to stealthily manipulate critical data such as meter readings, billing

information, or control commands

Integrity protection can be achieved by authentication,

certification, and attestation

Confidentiality

Confidentiality refers to protecting personal privacy and proprietary

information from unauthorized access. Malicious attacks targeting

confidentiality aim at obtaining desirable information(e.g., power usage, customer’s account information).

An emerging trend is for the smart meters to aggregate usage data

for billing purposes and support load-balancing and other

monitoring functions through peer-to-peer protocols that preserve

the consumer’s privacy.

Cyber Solutions

Data encrypton

Authentication

Digital signatures

Data Encryption

Cryptography

Cryptography has been the most widely used technique to protect information from adversaries. A message to be protected is transformed using a Key that is only known to the Sender and Receiver. The process of transformation is called encryption and the message to be encrypted is called Plain text. The transformed or encrypted message is called Cipher text. At the Receiver, the encrypted message is decrypted.

Substitution cipher

Transposition cipher

Authentication

Authentication is required to verify the identities of communicating

parties to avoid imposters gaining access to information.

Digital Signatures

A digital signature allows the signing of digital messages by the Sender

in such a way that:

1. The Receiver can verify the claimed identity of the Sender (authentication).

2. The Receiver can prove and the Sender cannot deny that the

message has been sent by the specific user (non-repudiation).

3. The Receiver cannot modify the message and claim that the

modified message is the one that was received from the Sender

Cyber solutions (academic)

An experimental study about the performance of a symmetric-key

cipher (i.e., DES-CBC) and a public-key cipher (i.e., RSA) on an intelligent electronic device (IED) called TS7250 has been

conducted (Wang and Lu, 2013), where the IED is used for sending

the transformer status and receiving commands from the control

centre.

These experimental results show that the computational ability of an

IED becomes a bottleneck for the delay performance when

performing asymmetric-key cryptography

Due to the limited computational capabilities of devices, stringent

timing requirements, and high data-sampling rates in the smart grid,

traditional authentication schemes might not be applicable.

Universal Key:The heterogeneous communication architecture of

the smart grid has made the key management particularly

challenging, and it is not practical to design a universal key-management scheme for the entire smart grid.

Authentication Security

Authentication is crucial to protect the integrity of data and devices

in the smart grid.

A number of authentication schemes have been proposed in the literature for smart grids. Szilagyi and Koopman (2009 and 2010)

proposed flexible and low-cost multicast authentication schemes for

embedded control systems

The basic idea is to verify truncated message authentication codes

(MACs) across multiple packets, thereby achieving a good trade-off

among authentication cost, delay performance, and tolerance to attacks.

Although many encryption, authentication, and key-management

schemes have been proposed, their performance does not seem to

fulfill the stringent timing requirements of the smart grid. Therefore,

fine-grained and advanced security protocols still need to be

developed for protecting different communication networks in

smart grids.

MACs

Imagine that you are communicating with your friend through a

chat client. How will your friend's machine know that the message

he received is exactly the same message that you send?. And how will he verify that the message was not altered in the middle.

Even after implementing a secure authentication and data

encryption, integrity of the message needs to be versified, to

confirm, that the data was not tampered in the middle.

In communication everything send over wire is data. So the thing

that will give the sender and the receiver the assurance, of

untampered data is also a small fixed length data called MAC(Message authentication code).

Confidentiality Security

In a smart grid, the utility company needs the real-time power-

consumption data for planning purposes as well as for providing

accurate and authentic billing. For the utility company, the correctness of the calculated bills is the most important issue

Researchers have designed privacy-preserving billing protocols

using advanced cryptographic techniques such as zero-knowledge

proof and homomorphic encryption

Zero-knowledge proof

If proving the statement requires knowledge of some secret

information on the part of the prover, the definition implies that the

verifier will not be able to prove the statement in turn to anyone else, since the verifier does not possess the secret information.

Homomorphic Encryption

Homomorphic encryption is a form of encryption which allows

specific types of computations to be carried out on ciphertext and

generate an encrypted result which, when decrypted, matches the result of operations performed on the plaintext.

This is a desirable feature in modern communication system

architectures. Homomorphic encryption would allow the chaining

together of different services without exposing the data to each of

those services, for example a chain of different services from

different companies could 1) calculate the tax 2) the currency

exchange rate 3) shipping, on a transaction without exposing the

unencrypted data to each of those services.[

Using those advanced cryptographic techniques, utility companies

only receive the commitments of the real-time power consumption

instead of the raw data from smart meters, and customers can prove to the utility company that a utility bill has been correctly

generated

However, from the customer’s perspective, privacy is the main

concern.

Garcia and Jacobs (2012) proposed the use of homomorphic

encryption to prevent the utility company from accessing the power

consumption data of individual households. Using those advanced cryptographic techniques, utility companies only receive the

commitments of the real-time power consumption instead of the

raw data from smart meters, and customers can prove to the utility

company that a utility bill has been correctly generated

SELF HEALING

What is Self Healing??

SELF-HEALING of power delivery systems is a concept that enables the identification and isolation of faulted system components and the restoration of service to customers supplied by healthy elements.

Self-healing of power distribution systems is conducted via Distribution Automation (DA), specifically through smart protective and switching devices that minimize the number of interrupted customers during contingency conditions by automatically isolating faulted components and transferring customers to an optional source when their normal supply has been lost.

Distribution Automation: Distribution Automation (DA) is a set of technologies that enable an electric utility to monitor, coordinate, and operate distribution components in a real-time mode from remote locations.

An illustration of self healing

Automatic fail over scheme for transmission fault

so that if one supply line fails, the customers supplied via that circuit are quickly transferred to the backup source by automatic failover control circuitry.

The limitation is while switching the load from second line to first line, the we need to check supply should be greater than load

There are several additional practical aspects that need to be

considered when implementing self-restoration, besides the DA

system architecture it is necessary to consider loading ratings and voltage limits, since transferring load to a highly loaded and long

feeder may end up generating power quality complaints (low

voltage in this case),

FLISR an application of Distribution

Automation

The smart grid concept is driving the implementation of a series of self-restoration schemes in the form of DA applications. The most popular of these is FLISR, which consists of the utilization of advanced protective and switching devices to automatically locate and isolate faulted feeder sections and restore the maximum number of customers possible located on healthy sections.

FLISR benefits include

Improve SAIDI, SAIFI, and other reliability statistics

Reduce “energy not supplied” (kWh)

Reduce fault investigation time

Provide “premium quality” service

Monetary benefits:

Reduce customer cost of outage

Increase revenue (sell more energy)

Advantages of implementing FLISR

the advantages of implementing FLISR versus conventional

operation for a typical distribution feeder when conventional

operation (without FLISR)

there is a need for investigating the specific fault location and

conducting manual switching to isolate the faulted area and restore

service to customers located on healthy feeder sections.

Here customer trouble call may play an important role.

FLISR on the other side allows detecting faults and restoring affected

customers faster and with limited human intervention.

When FLISR is used power is quickly restored to customers located on

healthy sections of a feeder.

The overall objective of this approach is to identify those locations and combinations of devices that attain the greatest cost-benefit ratio.

RENEWABLE

RESOURCES

The key goal of smart grid is to promote active customer

participation and decision making as well as to create the

operation environment in which both utilities and electricity users influence each other.

In smart grids, users can influence utilities by adding distributed

generation sources such as photovoltaic (PV) modules or energy

storage at the point of use, and reacting pricing signals.

SMART GRID RENEWABLE ENERGY

SYSTEM

The electricity grid to accommodate higher percentage of

renewable energy would need large quantities of conventional

back up power and huge energy storage.

Smart grid technologies and concepts reduce barriers to the

integration of renewable resources and allow power grids to support

a greater percentage of variable renewable resources.

Enabling smart grid technology, such as distributed storage,

demand response, advanced sensing, control software, information

infrastructure, and market signals, increases the ability to influence and balance supply and demand.

With smart grid technology, grid operators can better coordinate

and control the system in response to grid conditions, thus allowing

integration of increasingly greater levels of renewable resources

more effectively and at lower cost.

Advanced Metering Instrument (AMI) and internet-based services

engage demand response and distributed storage to

accommodate higher penetration and cost-effective integration of renewable energy generation.

Advanced and automated integration systems, such as inverters

and converters with communications software interfaces, enable

distributed management and application integration for renewable

generation.

SOLAR PV DESIGNS FOR SMART GRID

INTEGRATION

A typical solar PV should provide two-way flows of power and

communication between the smart grid and the solar PV system.

Three solar PV inverters are available which are the string, the

central and the newly developed micro inverter, known also as

integrated AC module inverter.

CENTRAL INVERTERS:

The conventional solar PV installations feed DC voltage to a central inverter for

conditioning and distribution locally or across the power grid.

The DC voltage carried through the array to the

central inverter may have significant fire and safety

hazards, leading to increased costs for cabling and,

in turn, higher costs for installation and

maintenance.

STRING INVERTERS

string inverters eliminate the need for a central inverter

by providing DC-AC conversion at the output of

each string.

MICRO INVERTERS:

Recent researches focus on micro inverters

which take the concept of string inverters to the

next level - providing DC-AC conversion from

each individual panel rather than an entire string.

algorithms for efficient DC-AC conversion, circuit protection

and PV panel power optimization through maximum power-point tracking

(MPPT) (di/dv) + (i/v) of the PV array is zero (derived from dP/dv = 0).

This concept is shown in this Fig. The processor and control unit is used to control

power flow from the PV panel to the grid and executes the MPPT algorithm, fault

control, and digital communication routines.

BENEFITS OF SMART GRID RENEWABLE

ENERGIES

First, enabling renewable energy resources to accommodate higher

penetration with cost effective while improving power quality and

reliability.

Second, integrating consumers as active players in the electricity

system; savings, achieved by reducing peaks in demand and

improving energy efficiency, as well as cutting greenhouse gas

emissions.

Finally, voltage regulation and load following enables reducing cost

of operations based on marginal production costs.

Future Advances and

Implementations of SMART

GRID

WinD EnergY

Smart grid integrates

all the small electric

heat pumps.

It controls or

coordinates a whole

lot of heat pumps according to the

variations in the

demand side.

If wind energy is

utilized properly, it would even satisfy the

electrical needs of the

country easily.

ElectriC VehicleS

We can say that the invention of

electric vehicles was a great

Achievement, even though it was

Invented a long time ago, its

Importance is seen with the advent

of this great technology Smart Grid.

Due to the use of electric vehicles,

there is a significant reduce in the

amounts of usage of fossil fuels and

thereby reducing the green house effect.

We can charge these vehicles whenever we need electricity and discharge this and

give it back to the system whenever the system needs it.

ActivatioN Of EquipmentS

This is the best feature

of SMART GRID. We

can know

Peak hours times and

the availability of

electricity at low cost times. We can

therefore use the

electricity efficiently

and economically.

ProsumerS

The producer is alerted

the condition of a low

electricity status, he can

thereby transfer the stored

energy to the required

place, with just a click on his phone.

No mediators are

involved in this process

ZerO EnergY HousE

A zero-energy building, also known as a zero net energy (ZNE) building, net-zero energy building (NZEB), or net zero building, is a building with zero net energy consumption, meaning the total amount of energy used by the building on an annual basis is roughly equal to the amount of renewable energy created on the site.

These buildings still produce greenhouse gases because on cloudy (or non-windy) days, at night when the sun isn't shining, and on short winter days, conventional grid power is still the main energy source.

The zero net energy consumption principle is viewed as a means to reduce carbon emissions and reduce dependence on fossil fuels.

ZerO EnergY HousE

Conclusion

Smart grid is the key to integrating large amounts of renewable

energy into the power system. The smart grid intelligently binds the entire energy system together and the most effective way of

expanding the power system to meet the challenges of the future.

After few years smart grid roll out will revolutionize the day–to-day life we use energy . With the advent of this technology people get

familiar with the theories of power systems.

In the 19th and 20th century electrification developed to the

industrial revolution, likewise in the 21th century is most likely to the significant contribution to the transition to the sustainable society

based on renewables to the benefit of people , the economy and

the environment through out the world

THANK YOU