Brownouts, Blackouts & Power Surges
A brownout is a voltage drop in the electrical power supply. It causes lights to become dim. Brownouts are not absolute power failure but they can significantly affect electrical equipments. Induction and three-phase electrical motors are at risk during a brownout as they can get overheated and their insulation and can get damaged. If the main power supply is erratic and one experience frequent brownouts, then he should consider for a backup power system that will automatically take over and provide with the necessary power when the voltage drops. In contrast, Blackouts is total loss of a power to an area and is the most severe form of power outage that occurs. Depending on the root cause of the massive blackouts, restoring power is often a complex task. The utilities and power stations must undertake and repair timeframes very greatly depending on the configuration of the affected electrical network. Power surges are the bane of any electrical system. A power surge can lead to rapid overheating and loss of critical and expensive equipment. Fortunately protection from such surges is available in the form of surge protectors and circuits breakers.
In today’s digital era, continuous quality 24/7 electricity is essential, as such advanced countries havedeveloped fully digitizedelectricity network. Electricity failures are critical as it is solely required forIoT or ICT. It is equally important at places where the environment and public safety are at risk -- institutions of public importance like airports, hospitals, water supply, sewage treatment plants, weather forecasting stations, financial institutions, etc. They are likely to have backup power sources such as standby generators, which will automatically come in operation once electricity supply is disrupted. Other important systems like telecommunication, mobile communications, real time monitoring devices are also required to have emergency power.
The Blackouts in History
a.USA – March 08, 2018:Hundreds of thousands of people were without electricity on Sunday, after a severe storm swept through much of the eastern United States two days ago on Friday. It took many days to attain full power restoration. Among those without power by mid afternoon Sunday were more than 67,000 in Maryland, 89,000 in New Jersey, and 157,000 in Massachusetts and in New York. State officials estimated 182,000 people remained without power even after 02 days of storm.
b. Puerto Rico, February 08, 2018:A fault in the electrical line led to the shutdown of two power plantsand as a result there was a complete breakdown of the system affecting approximately970,000 people.
c. Las Vegas, USA, January 10, 2018:The largest consumer electronics show in the world went into darkness in Las Vegas Convention Center. The electricity was lost due to massive rain which lasted about two hours and it damaged the electricity supply equipments.
d. Venezuela, December 18, 2017:A power outage hit parts of the Venezuelan capital Caracas as well as the nearby states of Miranda and Vargas for about five hours. Authorities blamed the outage, which began around noon, after collapse of an important cable linking a power plant and a transmission tower.
e. Puerto Rico, November 15, 2017:An outage from a repaired line was a cause of big blackout in the island. Millions of Puerto Ricans were without power after an already repaired high-voltage transmission line failed again. The outage came at an embarrassing time, following an announcement by government of 50% electricity restoration.
f. Taipei, Taiwan, August 16, 2017: Taiwan suffered a massive power blackout on Tuesday evening that hit businesses and residential homes, affecting close of seven million households on the heavily industrialized island amid sweltering heat. Millions were without electricity at home, offices and factories.
g. Sri Lanka nationwide blackout, March 13, 2016:It was nationwide blackout and 21 million people were affected. It was third nationwide electricity blackout within six months due to technical problem which disrupted the water supply to many parts of the island nation.Substation tripping was the cause of outage.
h. South Australia, February 02, 2017:It was a case of load shedding due to abnormal hot temperature, when electricity supply to about 40,000 households and businesses were deliberately cut amid soaring temperatures for approximately 45 minutes.
South Australia had another blackout on September 16, 2016 after a heavy storm swept and left entire state without power. Some places were without electricity for two days.
i. Kenya Nationwide black out, June 07, 2016:It affected 44 million people, when a monkey got inside a Power station and caused black out for 15 minutes but full restoration took around three hours.
j. Ukraine, December 23, 2015:It was an intentional cyber attack, first-of-its-kind cyber attack whichcut the lights to 225,000 people in western Ukraine, with hackers also sabotaging power distribution equipment, complicating attempts to restore power. Electrical power grids around the world have been infiltrated by hackers.
Researchers from Symantec, a security company, found proof of hundreds of power grid sites in the US, Turkey and Switzerland that can be hit by hackers.
k. Bangladesh, Nov 01, 2014:Approx 9 million affected for almost 8 to 10 hours. Bangladesh was hit by a blackout around noon on Saturday which ultimately led to near-total grid failure in Bangladesh side, which then led to electricity disruption of electricity which was traded from India to Bangladesh.
l. India, July 30-31, 2012 (Worst affected globally in terms of population):In the largest electrical outage in history (so far), the July 31st blackout of India affected an area encompassing about 670 million people, which is around 9% of the world’s population. On the 31st, three of the country’s interconnected northern power grids collapsed for several hours, affecting 22 states from the country's Eastern border with Myanmar to its western border with Pakistan.Citizens of Delhi dealt with 89% humidity and, in West Bengal, hundreds of miners were trapped underground for hours after their lifts broke down.
m.Brazil and Paraguay, November 10-11, 2009:When the Itapiu hydroelectric dam on the Paraguay-Brazil border suddenly stopped producing 17,000 megawatts of electricity, outages quickly spread through both countries, but suspiciously, the blackouts came two days after report that previous Brazilian power outages were caused by hackers.
n.Chenzhou, China, January 04 to February, 2008:Winter storms resulted in a nearly two-week blackout. Approximately 4.6 million people around the central Chinese city of Chenzhou were affected. Many citizens were without power during Chinese New Year celebrations. The official Xinhua News Agency said 11 line crew died while working to restore power, and the storm's death toll exceeded 60.
o. Germany, France, Italy and Spain, November 04, 2006:When German power company switched off a high-voltage line across the River Ems in order to let a cruise ship pass, 10-15 million Europeans lost power. The company said that the problems began in northwestern Germany when its network became overloaded, possibly due to that manual switch off (It was an abnormal case as the transmission lines had been shut down in the past without incident). It affected many neighbouring countries. Trains stopped in Germany and dozens of people were trapped in elevators in France and Italy. Austria, Belgium, and Spain were also affected by the outage.
p. Java and Bali, Indonesia, August 18, 2005:On Thursday morning, a failure in a 500 kilovolt transmission line between Cilegon and Saguling in West Java cut electricity supplies, leading to a massive 5,000 megawatt shutdown. Jakarta, the capital of the fourth most populated country in the world, lost power, and half of the Indonesian population -100 million peoplewere without electricity for almost 11 hours.
q. Italy, September 28, 2003:This blackout affected around 57 million people of Italy. Normally during late night. Usually a middle-of-the-night power outage means that few people will notice it. However, this event occurred during the early morning hours after Rome's Nuit Blanche, an all-night arts festival. Because of this, trains were still running at 3:01 a.m. when a fault on the Swiss power system caused the overloading of two internal lines near to the Italian border. About 110 trains carrying more than 30,000 passengers were stranded as a result.
r. United States and Canada, August 14-15, 2003:It took months before the real cause of the Northeast Blackout of 2003 was finally determined. Initially, Canadian Defense Minister John McCallum blamed an outage at a nuclear power plant in Pennsylvania, which the state's Emergency Management Agency denied. What actually happened was a high-voltage power line in Northern Ohio brushed against overgrown trees, causing it to shut down. When the alarm system that would typically alert First Energy Corporation failed, the incident was ignored. In the next 90 minutes, system operators tried to figure out what happened while three other lines switched off as a consequence of the first line's failure.
s. India, January 02, 2001:A 12-hour power outage caused by a failure of an Uttar Pradesh substation triggered India's northern grid to collapse. This affected about 226 million people, or roughly a quarter of the country's population. The Confederation of Indian Industry estimated that the loss to business amounted to about $107.1 million. Despite economic expansion in India, the blackout was used by some as an excuse to push for privatization of the electrical industry to bring it up to date. Enron was reported to have been contacted to help supply electricity during the crisis but insisted on a price that was three times higher than usual.
Causes of Power Failure
There are many causes of Power Failures. Electrical power, in last century has become an indispensable part of modern day life. Work, leisure, socializing, healthcare, economy, livelihood etc are very much depended on continuous electricity supply. Even a temporary interruption of electricity can lead to chaos, monetary setbacks, and possible loss of life. Our urban lives are totally dependent on continuous electricity supply and any interruption is unimaginable. Specially in case of Life-support systems in places like hospitals and nursing homes, or in co-ordination facilities such as in airports, train stations, and traffic control power outages can be disastrous. Most of the life support facilities have source of backup power that is ready to automatically take over in case of grid failure. Airports, mines and nationally important installations have multiple Grid supply source besides standby electricity. Backup power is also increasingly being used in corporate facilities, manufacturing, shopping malls, and even residential houses as the dependence on electronics and computers in our daily lives increases. While a loss of power in smaller scale settings may not be life threatening, it can result in lost data, missed deadlines, decrease in productivity or revenue.
Possible causes of power failure: Some of the obvious, and some not so obvious, causes of power failure:
(1) Natural Causes - Weather Related: More than 50% of power outages are due to adverse weather. Many power failures are caused by natural weather phenomena such as lightening, rain, snow, ice, wind, and even dust. It is very difficult to safeguard the system from major power failure due to natural calamities like floods and severe storms. It does not take much to safeguard electrical systems from the effects of water and dust. Water can lead to short circuits and power failure. Electrical switchboards, wires, and circuits should be protected from exposure to water. Dampness and excessive moisture can also lead to serious damages. If you live in areas with high levels of humidity, you should consider use specially sealed circuit protection devices. Dust can also wreack havoc with electrical systems and lead to short circuits and power failures.
Natural disasters have historically been at the root of the world’s most severe power outages. Hurricanes, floods, wind storms, earthquakes, tsunamis, and other severe weather can completely destroy critical power infrastructure and result in outages that leave expansive geographic regions without power for days, weeks, and even months.
(2) Other Causes of Outages - Animals coming into contact with power lines like snakes by eagles, large birds etc, accounted for more than 10% of outages. Additional causes of failures are due to equipment failure. Accidents were primarily man made outages and occasional human error.
Short Circuits - A short circuit is the most commonly used term to describe the cause of a power failure. Unfortunately, it is also a term that is bandied about without people having much knowledge of what it actually means. A short circuit occurs when an electric current travels along a path that is different from the intended one in an electrical circuit. When this happens, there is an excessive electric current which can lead to overloading, circuit damage, fire etc. In fact, short circuits are one of the primary causes of electrical fires throughout the world.
Prevention & Safety - Now that we are aware of the possible causes of short circuit. Let us look at some of the ways in which we can safeguard our electrical systems from the hazards they pose. First and foremost, all the equipment that is used in electrical installation is composed of good quality materials of correct specification for your application. The initial installation costs may be higher than a system made with cheaper materials but the savings you will make in avoiding potential losses caused by short circuits and maintenance can be substantial, not to mention the additional safety and peace of mind you get.
Wires should always be of the highest quality and of the correct gauge for your application. It should also be kept in mind that wires and other electrical circuits should not be overloaded. Electrical overload leads to overheating, causing break down, which in turn can lead to a short circuit. Pumps, pistons, rotors and other moving parts of an electric motor should be regularly serviced and checked to ensure that there is no jamming. High quality protections devices should be installed so that power can be immediately disconnected in the event of a short circuit, thereby preventing damage to whole equipment. Use Protections of proper rating. Water is another frequent cause of short circuits. It should be ensured that all exposed circuits are kept covered and protected from moisture.
Electrical trees- Electrical treeing is a phenomenon that affects high power installations such as high voltage power cables, transformers, etc. Any mechanical defects in the equipment used in high voltage installations can lead to partial electric discharges in the equipment. The damaging process manifests itself in a tree-like pattern, hence the name electrical treeing. Over a period of time, if it is undetected, then this phenomenon can lead to a continuous degradation of the equipment and eventually result in a total breakdown.
In order to combat electrical treeing, it is important to use high quality materials that are designed to handle the electric load. Regular maintenance by trained engineers can also help to identify and rectify electrical treeing before it can cause a major breakdown.
Summary
Electric power is critical to society and business alike. Weather is responsible for the majority of major power outages that occur, besides other causes that should be accounted for when designing an electrical system. For any critical systems, be it emergency or business related, you should always get the assistance of a certified qualified expert and always install a standby system may be in form of renewable source or power generator.
So one can see that so far none of the Smart technologies could find a solution to prevent black out and advanced countries like USA, Australia, Canada, Germany, India, China etc are no exception. It is not only weather but also technology which sometimes creates the nuisance.
A misconception prevails among Transmission companies that due to storm the Distribution companies cut off their system and as a result due to sharp fall in electricity consumption, imbalance takes place and as a result massive blackout may occur. But it is the job of the Distribution or other related companies to safe guard their equipments otherwise long term effects of localized electricity distribution problem may occur for long periods. The Transmission Companies should have fully automatic network together with Generation and Distribution which will automatically balance the system even in most adverse situation.
Engr. Saddaf Haider;
ICT Expert,
Email: saddafhaider@gmail.com
