By: Soumen Sahu

WHAT IS BLACKOUT?

•A blackout refers to the total loss of power to an area and is the most severe form of power outage that can occur.

•Blackouts which result from power stations tripping are particularly difficult to recover from quickly. Outages may last from a few minutes to a few weeks depending on the nature of the blackout and the configuration of the electrical network.

• August 2003: North America. 50 million people affected during two days; New York City loses power

• September 2003: Switzerland-France-Italy. 57 million people affected during one day; Italy loses power

• Other major incidents in recent years in Europe and Brazil

• July 2012 :Northern and Eastern India ,Largest power outage in history, Affecting 620 million people during 2 days,9 % of world population and half of Indian population

Recent major incidents

EXAMPLE OF INCONVENIENCE DUE TO BLACKOUT

The recent Indian blackout shut down trains (including Delhi's metro

system), stopped water delivery systems, trapped miners

underground, shut down air conditioners during intense heat, caused as much inconvenience as

you can imagine.

Classification of blackouts

• Transmission inadequacy: a failure in a transmission network causes a cascading overloading of the network (a majority)

• Generation inadequacy: failures of power plant(s) cause a deficit of generation (GB 2008 disturbance)

• Usually a mixture: an initial network fault causes a separation of the network into parts with deficit/excess of generation

Pre-conditions and Factors for Blackouts

• Inadequate maintenance

• Aging equipment, prone to failures • Insufficiently coordinated equipment

maintenance and generation scheduling

• Weather (high temperatures; wind, thunderstorm, fog, etc.)

How does a blackout develop?

Individual line failure system fails

Individual power lines fail due to:

• External effects: fires, lightning strikes, tree contacts.

• Thermal effects: an overloaded line will melt -- usually requires several minutes

(protection equipment will shut it down first)

POWER PLANT TRIPS OFF LINE• Lightning Strike, fire, overload

• When that plant disconnects from the grid, the other plants connected to it have to generate more to meet the demand.

• If they are all near their maximum capacity, then they cannot handle the extra load. To prevent themselves from overloading and failing, they will disconnect from the grid as well.

• That only makes the problem worse, and dozens of plants eventually disconnect. That leaves millions of people without power.

TRANSMISSION LINE FAILURE• Lightning/Sagging/overload

• When that transmission line failed, all of its load shifted to neighboring transmission lines. They then overloaded and failed, and the overload cascaded through the grid.

• The multiple failures make the problem worse and worse and a large area ends up in the dark.

Cascading failureInitial set of externally caused faults:Several lines are disabled

The network is altered – new power flows and loading

flows in some of the lines exceed the line ratings

Further line shutoffs

New network: new power flows

Cascade !

Cascading events that cause disturbances to propagate• Sequential tripping due to overloads, power swings,

and voltage fluctuations• Protection mis-operation & incorrect settings

involved in ~70% of blackout events in North America

• Inadequate or faulty EMS/SCADA system • E.g. alarm burst causing 2003 U.S. blackout

more serious • Insufficient reactive support where and when

required• Inability of operators to prevent further propagationThe leading cause of the blackout is: Inadequate System

Understanding & lack of situational awareness

INDIA BLACKOUT 2012 OVERVIEW

• Gap between power demanded and power generated was 9% in avg.

• Due to late monsoon hydro power plants generated less.• Intense heat caused more electricity usage.• Farmers in Punjab and Haryana used electric pump for

irrigation=>more pressure on grid.• 400 kV Bina-Gwalior line tripped. As this line fed into the

Agra-Bareilly transmission section, station failed and power failure cascaded through grid.

• Previously overloaded grid caused cascading more rapid.

HOW TO REDUCE BLACKOUT????To reduce the risks of blackouts we need to improve the

engineering state.

•Monitoring the operation of a system in real-time,to establish safe operating levels and to identify parts prone to cascade failure. •Improvising scada/ems (software)•The economy needs to build better transmission lines and protect them from chain-reaction outages that can blackout cities one after another.•A new technology known as "superconductivity" cable has been proposed to fix the problem. This nitrogen-cooled transmission line, now under development, could carry up to 25 times more electricity than today's standard copper cable can. That means it could absorb power surges and other assaults.

Application of new modelling techniques: preventive network splitting

• Exciting collaboration between graph theorists and power engineers

• Split the network in a controlled manner before it partitions itself

• New mathematical modelling tools required to prevent future blackouts

Proactive modelWe can upgrade a network in a number of ways. Examples:

Upgrade individual lines

Add new lines:

Join/split nodes:

Smart grid

A smart grid puts information and communication technology into electricity generation, delivery, and consumption, making systems cleaner, safer, and more reliable and efficient. U.S. Department of Energy Definition: A smart grid integrates advanced sensing technologies, control methods, and integrated communications into the current electricity grid.

Grid Modernization

Today’s Electricity …

Power park

Hydrogen Storage

Industrial DG

Tomorrow’s Choices …

Combined Heat and Power

Fuel Cell

e -

e -

Wind Farms

Rooftop Photovoltai

cs

Remote

Loads

Load as a resource

SMES

Smart Substation

Fuel Cell

Smart Grid requirementsApplications supporting reliability and efficiency

meter data based outage management

increasing grid capacity: asset utilization,

power flow control

energy storagestationary & mobile emergency power peak power

undergroundpower cables

substation and feeder automation

home automation/demand response

load management/ demand response

grid operation with distributed generation

network management cyber security outage management remote fault location

local balancing of distributed resources

- Microgrids

Smart Grid Drivers for IndiaReduce T&D

losses, Improve quality of supply

Manage peak power to reduce outages – Demand Response

Integrate Renewable/Distributed Generation to the

Grid efficiently

THE END!!!!

SO BE AWARE WHEN WE USE ELECTRICITY AND THE WORLD WILL BE A BETTER AND SAFE PLACE!!!

THANK YOU!