WHAT IS BLACKOUT?•A blackout refers to the total loss of power toan area and is the most severe form of poweroutage that can occur.•Blackouts which result from power stationstripping are particularly difficult to recoverfrom quickly. Outages may last from a fewminutes to a few weeks depending on thenature of the blackout and the configuration ofthe electrical network.
Recent major incidents• 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
EXAMPLE OF INCONVENIENCE DUE TO BLACKOUT The recent Indian blackout shut down trains (including Delhis 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 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) Individual line failure system fails
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 failure Initial set of externally caused faults: Several lines are disabled The network is altered – new power flows and loadingflows 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 requiredThe • Inability of operators to prevent further propagation leading cause of the blackout is: Inadequate SystemUnderstanding & 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 safeoperating levels and to identify parts prone to cascade failure.•Improvising scada/ems (software)•The economy needs to build better transmission lines and protectthem from chain-reaction outages that can blackout cities one afteranother.•A new technology known as "superconductivity" cable has beenproposed to fix the problem. This nitrogen-cooled transmissionline, now under development, could carry up to 25 times moreelectricity than todays standard copper cable can. That means itcould 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 model We can upgrade a network in a number of ways. Examples: Upgrade individual linesAdd new lines:Join/split nodes:
Smart grid A smart grid puts information andcommunication technology into electricitygeneration, delivery, and consumption, makingsystems cleaner, safer, and more reliable andefficient.U.S. Department of Energy Definition: A smart grid integrates advanced sensingtechnologies, control methods, and integratedcommunications into the current electricity grid.
Grid ModernizationToday’s Tomorrow’sElectricity … Choices … Power park e- Fuel Cell Hydroge Wind n Storage Remot Farm Industrial e s DG Loads Fuel Cell Rooftop Photovoltai e- SMES cs Smart Substation Load as a resource Combined Heat and Power
Smart Grid requirements Applications supporting reliability and efficiency network management underground cyber security power cables outage management remote fault location increasing grid capacity: asset utilization, power flow control home automation/ load management/ demand response substation and demand response feeder automation energy storage meter data based grid operation with stationary & mobile local balancing ofoutage management distributed emergency power distributed resources generation peak power - Microgrids
Smart Grid Drivers for India Reduce T&D Manage peak power tolosses, Improve quality reduce outages – of supply 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!!!