A cascading failure is failure in a system of interconnected parts, where the service provided depends on the operation of a preceding part, and the failure of a preceding part can trigger the failure of successive parts. Redundant parts can lessen the impact of, but not prevent, a failure. In engineering, the duplication of critical components of a system with the intention of increasing reliability of the system, usually in the case of a backup or fail-safe, is called redundancy. ...

Cascading failure in power transmission

Cascading failure is common in power grids when one of the elements fails (completely or partially) and shifts its load to nearby elements in the system. Those nearby elements are then pushed beyond their capacity so they become compromised and shift their load onto other elements. Cascading failure is a common effect seen in high voltage systems, where a single point of failure (SPF) on a fully loaded or slightly overloaded system results in a sudden spike across all nodes of the system. This surge current can induce the already overloaded nodes into failure, setting off more overloads and thereby taking down the entire system in a very short time. Transmission towers Transmission lines in Lund, Sweden Electric power transmission, or more accurately Electrical energy transmission, is the second process in the delivery of electricity to consumers. ... In electrical engineering High voltage refers to a voltage which is high. ... Reliable system design is the design of systems with high levels of reliability and availability. ...

This failure process cascades through the elements of the system like a ripple on a pond and continues until substantially all of the elements in the system are compromised and/or the system becomes functionally disconnected from the source of its load. For example, under certain conditions a large power grid can collapse after the failure of a single transformer.

Monitoring the operation of a system, in real-time, and judicious disconnection of parts can help stop a cascade. Another common technique is to calculate a safety margin for the system by computer simulation of possible failures, to establish safe operating levels below which none of the calculated scenarios is predicted to cause cascading failure, and to identify the parts of the network which are most likely to cause cascading failures. ^{[citation needed]} Realtime redirects here. ...

Other examples of cascading failure

Analogues to this exist in biology of cascade-like effects where a small reaction can have system-wide implications. One example to this is the release of toxins caused by a small ischaemic attack, which kill off far more cells than the initial damage, resulting in more toxins being released. Current research is to find a way to block this cascade in stroke patients to minimise the damage. For other uses, see Toxin (disambiguation). ... In medicine, ischemia (Greek ισχαιμία, isch- is restriction, hema or haema is blood) is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. ...

Another example is the Cockcroft-Walton generator can also experience cascade failures, where one failed diode can result in all the diodes failing in a fraction of a second. The Cockcroft-Walton (CW) generator, or multiplier, was named after the two men who in 1932 used this circuit design to power their particle accelerator, performing the first artificial nuclear disintegration in history. ... Closeup of the image below, showing the square shaped semiconductor crystal various semiconductor diodes, below a bridge rectifier Structure of a vacuum tube diode In electronics, a diode is a two-terminal component, almost always one that has electrical properties which vary depending on the direction of flow of charge...

Yet another example of this effect in a scientific experiment was the implosion in 2001 of several thousand fragile glass photomultiplier tubes used in the Super-Kamiokande experiment, where the shock wave caused by the failure of a single detector appears to have triggered the implosion of the other detectors in a chain reaction. In an explosion (top), force radiates away from a source. ... Year 2001 (MMI) was a common year starting on Monday (link displays the 2001 Gregorian calendar). ... Super-Kamiokande, or Super-K for short, is a neutrino observatory in Japan. ...

Examples

• Northeast Blackout of 1965
• Northeast Blackout of 2003
• 2003 Italy blackout

A map of the states and provinces affected The Northeast Blackout of 1965 was a significant disruption in the supply of electricity on November 9, 1965, affecting Ontario, Canada and Connecticut, Massachusetts, New Hampshire, Rhode Island, Vermont, New York, and New Jersey in the United States. ... A map of provinces and states that had areas of blackout, including minor ones. ... The 2003 Italy blackout was a serious power outage that affected all of Italy, except the island of Sardinia for 9 hours and part of Switzerland near Geneva for 3 hours on 28 September 2003. ...

See also

• Byzantine failure
• Chain reaction
• Congestion collapse
• Cascading rollback
• Cascade failure (Internet)

In fault-tolerant distributed computing, a Byzantine failure is an arbitrary fault that occurs during the execution of an algorithm by a distributed system. ... A chain reaction is a sequence of reactions where a reactive product or by-product causes additional reactions. ... In data networking and queueing theory, network congestion occurs when incremental increases in offered load lead either only to small increases in network throughput, or to an actual reduction in network throughput. ... This article or section does not adequately cite its references or sources. ... When a system composed of interdependent elements is loaded at or near capacity, the system may suffer a complete failure if one (or more) of its elements is compromised. ...

External links

• Space Weather: Blackout - Massive Power Grid Failure
• Cascading failure demo applet (Monash University's Virtual Lab)
• A. E. Motter and Y.-C. Lai, Cascade-based attacks on complex networks, Physical Review E (Rapid Communications) 66, 065102 (2002).
• Protection Strategies for Cascading Grid Failures — A Shortcut Approach
• Ian Dobson, Benjamin A. Carreras, and David E. Newman, preprint A loading-dependent model of probabilistic cascading failure, Probability in the Engineering and Informational Sciences, vol. 19, no. 1, January 2005, pp. 15-32.
• Nova: Crash of Flight 111 on September 2, 1998. Swissair Flight 111 flying from New York to Geneva slammed into the Atlantic Ocean off the coast of Nova Scotia with 229 people aboard. Originally believed a terrorist act. After $39 million investigation, insurance settlement of $1.5 billion and more than four years, investigators unravel the puzzle: cascading failure. What is the legacy of Swissair 111? "We have a window into the internal structure of design, checks and balances, protection, and safety." -David Evans, Editor-in-Chief of Air Safety Week.
• PhysicsWeb story: Accident grounds neutrino lab