Quiz 5

Resistance

voltage divided by current.

Power

volts times current.

Solid, Generators, Voltage, Current, Voltage

Alternating current is the ___ line. The main advantages of alternating current are it is easier to build AC ___ and to convert from one AC ___ to another. Losses in AC transmission effect their ___, not their ___.

Voltage, Current, Phases, Voltage, Phases

Alternating current transmission line can carry more power if you increase either the ___ or ___ or send multiple ___ of AC down the line, but they will lose less power if you increase the ___ and use three ___.

Collateral, Lines

During wars, many countries attempt to limit civilian or ___ damage, but power ___ are often destroyed.

Direct, Alternating, Alternating

Electricity can be passed through a wire using ___ current or ___ current. There are advantages and disadvantages to both methods in power transmission, but currently, ___ current has more advantages.

Sub-Stations, Foundations

Floods can destroy ___ and ___ of the power line towers and poles.

Reactance, Calculus, Amps, Volts, Ohms, Voltage, Resistance

The impedance is related to something called ___. To formally define it, we need to use differential ___ to understand how capacitance and inductance works. So, let us turn to another analogy: when you try pass an electron flow through a wire (current in ___), the voltage (in ___) helps you, yet the resistance (in ___) limits you. The higher the ___ (V), the higher the current (I). The higher the ___ (R), the lower the current (I).

1880, 1930, US, Canada, Safe, Reliable

The first modern use of electricity did not exist until ___. Parts of the US did not receive electrical power until the ___s. Today, our electricity come from a power grid that connects almost every part of the ___ and ___. The system is designed to be ___ and ___, but failures can happen.

Transmission, Plants, Substations, Lines, Low

The power grid components are a web of high voltage ___ lines, power ___ generating power at about 25,000 volts, power ___, and power ___. The power is converted to ___ voltage.

Fires, Disruptions

Transformers can fail, causing serious ___ or power ___.

Fuel Type, Location

effects cost, safety, and environmental impact in generation.

Transmission Type, Location

effects cost, safety, and environmental impact in transmission.

Generation, Transmission

the two major issues of the 'power grid' concept.

Dead, Electricity

Your appliances could be designed to use much higher voltages, but, we would have to spend too much time picking up all of the ___ bodies for this to be a good idea. Therefore, we need a way to convert voltages so we can transmit the ___ at high voltages, but, generate and use it at lower voltages.

Operators, Careless

___ are people who make mistakes. People who do the same thing day-in and day-out get ___.

Operators, Switch, Voltage, Current, Load, Coming, Going

___ must carefully monitor the state of all lines. If a power plant, sub-station, or line fails, the grid will try to ___ around problems. As a result, too much ___ or ___ may be applied to a working line causing it to also fail. There will be a ___ balance in the overall grid within milliseconds. Power ___ in must match power ___ out.

Geomagnetic, Poles

___ storms can create large power surges on many lines over a wide area. It is most likely to happen closer to the north and south ___.

Transmission, Haul, Used, Voltage, Distance, Tap, Expensive

A ___ line can carry more power if you use direct current instead of alternating current, but, there are problems with DC transmission. As we start to run out of space to put new lines, some long ___ lines are being converted to DC despite these problems, but, there are some limits to how they can be ___. Since the ___ drop on a DC line is proportional to its ___, you can figure out what this drop will be for a given line and compensate for it, but you cannot ___ into the line at any point. DC to AC converters are still very ___.

Alternating, Parallel, Minimum, Buried, Lines, Towers, Lightning, Resistance, Farm, Humans

A direct problem with ___ current is capacitance. Capacitance between ___ lines limits how much power you can send over a line and the ___ spacing between lines. Capacitance between the lines and ground limits how much of the grid can be ___. Another problem is lines above the surface that can be damaged by wind, ice, and objects hitting the ___ or ___ or can be hit by ___ strikes, which can damage transformers and other equipment. Also, stray currents can be created in the area surrounding a transmission line, which are caused by line ___. They can kill or harm ___ animals and/or ___.

High, Substations, Voltages

A web of ___ voltage transmission lines are connected together by transmission ___. These lines use a wide range of ___ [33,000 to 765,000 volts].

Reliability, Cascading, Communication, Occurs

After the Northeast Blackout, the Northeast ___ Council is formed to ensure that standard practices are followed by each power plant to avoid a ___ problem. Proper ___ practices are followed in the event that a problem is detected. Due partly to their work, a similar problem never ___ again.

Alternating, Phase, Plants, Lines, Humans, Animals, Voltage, Current

An indirect problem with ___ current is that power generation must be carefully monitored to ensure that all generators are in ___ with each other. Otherwise, damage to the power ___ and/or transmission ___ can occur. Another problem is that ___ and most ___ run on it. Almost any ___ and ___ can be dangerous.

Sir Adam Beck, Offline, Generators, 5

At 5:16 p.m. ET on November 9, 1965, a single power line at the ___ Station No. 2 at Niagara, Ontario trips ___. Within seconds, other lines out of the plant overload and trip, shutting down the plant's ___, causing the Northeast Blackout. Within ___ minutes, the power distribution system in the northeast experiences a cascading effect with the system breaking up into "islands" of distribution plant after plant experience load imbalances and automatically shut down.

Circuit, Nut, Con Ed, Big Allis

At 8:37 p.m. ET on July 13, 1977, a lightning strike at a substation on the Hudson River trips two ___ breakers in Westchester County. Due to a loose locking ___, the breaker is not able to reclose without the substation. ___, the power provider for New York City and some of Westchester County, cannot generate enough power within the city and the three power lines that supplemented the city's power are overtaxed. Just after 9:27, the biggest generator in New York City, ___ in Queens, shuts down and with it, all of New York City, which is known as the New York City Blackout.

Geographic, Monopolies, 75

Before the current power grid developed, a single company produced, transmitted, and distributed power for a ___ region. As these companies became bigger, they became natural ___, or "a single company is the only supplier of a particular kind of product or service due to the fundamental cost structure of the industry." By the 1930's, ___% of all power was controlled by large interstate holding companies.

Transformer, Increased, Decreased, 2, 3

By using a special kind of ___, the number of phases can be ___ or ___, but normally only ___ or ___ phases are used.

40, Retail, Prices, Nuclear, Natural, Hydroelectric, Plants, Climb, Drought, Private, Long

California's deregulation plan of 1998 includes selling off about ___% of the production capacity. It is capping ___, but not wholesale ___. It is moving from ___ to ___ gas as a fuel source. It is buying cheap, ___ power from other states instead of building or upgrading power ___. In 2000, natural gas prices drastically ___. A ___ shuts off much of the hydroelectric power imports. By 2001, a large amount of ___ producers in the state cannot sell power for what is costing to make it so they file for bankruptcy. The state steps in, but it does not have the money to make ___-term contracts.

Above, Towers, Poles, Redundant, Meet, Short, Surge

For the most part, electrical power lines must travel ___ ground. Things can hit them or damage the ___ and ___ that carry them. We can only run a limited number of ___ lines so the loss of a single line is going to most likely cause something to fail. Even if we could run many more lines than we need, there are going to be single points of failure where they ___ which can also fail. Unless the line is quickly removed from the system, a ___ or ___ on a connected line is going to move to the next piece of the system.

Magnetic, Navigation, Migration, Living, Cancer, Evidence

High voltage lines can locally change the earth's ___ field, causing problems for human ___ aids and messing up the ___ patterns of some animals. Long term exposure, like ___ under one, may cause some forms of ___. The ___ for this is not conclusive either way.

Down, Objects, Short Out

High winds can directly ___ lines, blow ___ into them, and cause lines to touch, and thus, ___.

Winds, Waves, Flood

Hurricanes can create very high ___ and ___ as well as ___ conditions.

Weigh, Grounds

Ice storms can ___ down lines causing them to break. It touches something that electrically ___ them.

Superconductors, Lightning, Routing

If we can figure out the direct current to alternating current converter problem, new DC transmission lines could be added that use ___ to greatly reduce loss and be buried in the ground to reduce the effect of ___ and other above-ground ___ problems.

Public Utility Holding Company, New Deal, Monopolies, Local, State

In 1935, the ___ Act was signed. It was part of the ___. It created limited-territory government-sanctioned ___. ___ or ___ governments either owned these companies outright or regulated them to control their service and profits.

Crime, Race, Temperatures, Looting, Rioting, Fires, Arrested, 300, Maintenance

In 1977, NYC is going through some bad times: high ___, bad ___ relations and very warm ___ all make the conditions right for unrest. Because the power failure occurs at night, 1,616 stores were damaged in ___ and ___; 1,037 ___ occur, including 14 multiple-alarm ones; and 3,776 people were ___. A Congressional study estimated the damage at $___ million. It is later determined that poor ___ of the substation is to blame for the initial failure.

Electricity, Utilities, Power, Retail

In 1992, the National Energy Policy Act allowed power producers to compete for the sale of ___ to local ___. This created the first part of the modern economic structure where wholesale ___ production is a separate business from ___ distribution.

Transmission, Company, State, Produces, Buys

In 1996, the Federal Energy Regulatory Commission issued an order which requires utilities to open their ___ lines to competitors. This created the second part of the modern economic structure where consumers can pick which power ___ they want to use assuming that their ___ passes the necessary laws to support it. Of course, the electricity is still transmitted the same way, but money now changes hands based on who ___ the electricity and who ___ it.

Economics, Growth

In ___, governments tend to fix problems after they happen, not before. Our infrastructure is not keeping up with our population ___.

Turns, Drop, Loss

In a transformer, the ratio of the number of ___ (N) in each wire determines the relative voltage ___ (V) across each winding, so by applying a current (I1) to one of these wires at a voltage (V1) we can generate a current (I2) in the other wire at voltage (V2). Since there is little power ___ in a transformer, the relationship between these wires will be very close to V1I1 = V2I2 where the ratio of the currents will be inversely proportional to the ratio of the voltages.

Component, Grid

In chain-reaction failures, the failure of one ___ is not addressed quickly enough, so it causes other failures. Without additional quick actions, large portions of the ___ may be effected.

High, Voltage, Physical

In many areas, we are starting to run out of space to put new ___ voltage lines. One very short-term solution is to increase the ___ on these lines, but there are ___ limits to how far you can increase it.

Lines, Sub-Stations, Disaster

In nature, power ___ and ___ areeverywhere. It is just a matter of time before someform of natural ___ will hit somepart of them.

Million, 4, Toluca Receiving, Order, Incidents

In the Los Angeles Blackout, over a ___ people in the Los Angeles area lose power, some for over 4 hours. The cause is an employee inadvertently cuts a control wire at the ___ Station during normal maintenance of the lines. The work ___ was written wrong. The problem is fixed without any major ___.

Electricity, Energy Wave, Electron Flow

In the basic theory of generation, ___ is generated simply passing a wire through a magnetic field. An ___ is generated depending on the angle of the wire with respect to the magnetic field. By turning the wire in a wheel fashion, the ___ will follow a wave shape behavior.

Bed, Flow, Elevation, Stop

In the transmission river analogy, rivers flow because they have a channel or ___. The bigger the channel, the more water can ___ through it. Their channel drops in ___ from their source to their mouth. The bigger the drop, the harder it is to ___ the flow.

Thunderstorm, Leaves, Dripped, Absorbed, Evaporated, Wire, Delay, Absorption, Evaporation, Voltage, Air

In the transmission wet tree analogy, it starts to rain, so you run under a tree, which is not a good thing to do if it is a___. For a little while, the tree's ___ catch the rain and you stay dry, but, at some point there is too much rain for it to hold and you start getting wet. It stops raining, but the tree will keep dripping until all of the rain has either ___ out, been ___, or ___. This is basically what capacitance and inductance do to a ___. The ___ part is a pain, but the real problem is the ___ and ___. One way to fix this is faster flowing rain (I.e., increase the wire's ___). Another way is to put the line higher in the ___ to get it away from the ground (another source of capacitance).

Bad, Power, Iron, Magnetic, Wave

In transmission mutual inductance, while inductance can sometimes be ___, it can also be used to help us transmit ___. If we wind two insulated wires around the same ___ core, we create something called a transformer. Transformers work because inductance isdriven by the ___ part of anelectromagnetic ___.

Break, Fire, Transformers

Lightning strikes can generate a huge surge on a line causing the line to ___ or catch ___ (a fairly rare event). It is the quick destruction of the connected ___.

Water, Transmission, Bigger, Voltage

Like ___, electricity also flows. ___ lines act like the channel. The ___ the lines, the more current (I) can flow through the line. The bigger the ___ (V) being carried, the harder it is to stop the flow.

Equipment, Life, Fires, Disruptions

Lines can fail, causing other ___ damage, loss of ___ and/or structure ___, or power ___.

Lines, Sub-Station, Lines

Maintenance workers need to keep ___ and ___ components is good working order and keep things away from around and under the power ___.

Loads, Cleveland, Ohio, Power, Tree, Offline, System, Breakers, Surge, Michigan, Transmission, Eastward, Generators, Seconds

On August 14, 2003, at 1:58 pm, the North American Blackout started when an Eastlake, Ohio power plant shuts down, changing ___ on related power lines. At 3:06 pm, a 345-kV transmission line fails south of ___, Ohio. At 3:17 pm, voltage dips temporarily on the ___ portion of the grid. Controllers take no action, but ___ shifted by the first failure onto another power line. At 3:32 pm, a loaded power line sags into a ___ and trips ___. While controllers try to understand the failures, they fail to inform ___ controllers in nearby states. At 3:41 and 3:46 pm, two ___ connecting the problem area to rest of grid trip. At 4:05 pm, a sustained power ___ occurs on some Ohio lines. At 4:09:02 pm, voltage sags deeply as Ohio draws 2 GW of power from ___. At 4:10:34 pm, many ___ lines trip out, first in Michigan and then in Ohio. It blocks the ___ flow of power. ___ go down, creating a huge power deficit. In ___, power surges out of the east coast generators.

Wholesale, Davis, Wholesale, Plants, Northern, Central, End, Long, Begin, End, Federal

On January 17, 2001, the California Electricity Crisis occurs, or the state runs out of ___ power. Governor ___ declares a state of emergency. It allows the state to start buying ___ power. It streamlines the process for building new power ___. It starts rolling blackouts in ___ and ___ California. On January 19, 2001, these rolling blackouts ___. On March 19, 2001, the state can no longer buy enough power (due to a lack of ___-term contracts). Rolling blackouts ___ statewide. On March 21, 2001, rolling blackouts ___ statewide. In May, the problem is 'solved' with the help of the ___ government.

Power, Hydrogen, Organic, Plants, Pipes, Cell, Technology, Trillions

One possible future is the replacement of the ___ grid with a '___ grid'. The process is that ___ material like garbage is broken down at large 'power ___' to produce hydrogen, this hydrogen enters a vast network of underground ___ which eventually route it to your house, and a fuel ___ about the size of your outside A/C unit converts this hydrogen to water to create electricity for your home. We current have the ___ to do this, but the cost to do it will be in the ___ of dollars.

Substations, High, Distribution

Power ___ convert the ___ voltage to ___ (or power line) voltages[3,300 to 25,000 volts].

Plants, High, Substations

Power ___ generating power at about 25,000 volts are connected to the ___ voltage lines by special ___.

Equipment, Lines, Disruptions

Switching equipment can fail, causing other ___ or the transmission ___ to be damaged or power ___.

Wide, Plants, Fuel, Pollution, Transmission

The 'power grid' concept allows us to share electricity over ___ areas, but it requires the use large power ___ to improve the efficiency of converting the ___ to electricity and to reduce the ___ of power generation. It also requires the ___ of power over long distances.

Ontario, 8, 6, 24

The North American Blackout in 2003 affected 10 million in ___ (about one-third of the population of Canada) and 40 million in ___ U.S. states (about one-seventh of the population of the U.S.) They had a loss of $___ billion and the power was out for up to ___ hours.

Trees, Software, Alarms, Staff, 100

The North American Blackout was an Ohio power line problem caused by not trimming ___ as necessary. Operators did not take remedial action or warn other control centers until it was too late because of a bug in the ___ being used. It prevented ___ from showing on their control system. Inadequate ___ were available to detect and correct the bug. The cascading effect resulted in more than ___ power plants tripping offline.

Northeast, 25, 12

The ___ Blackout in 1965 affected Ontario as well as Connecticut, Massachusetts, New Hampshire, Rhode Island, Vermont, New York, New Jersey. Around ___ million people in 80,000 square miles (207,000 km²) were without electricity for up to ___ hours.

Resists, Impedes

When you try to transmit power through a wire, the wire ___ the flow of direct current and ___ the flow of alternating current.

Earthquakes

can destroy any part of the grid.

Power Lines

routes the power to end users.

Direct Current

the dashed line.

Nature, Wars, Economics, Operators

the four enemies of the power grid.

Lines, Transmissions, Switching Equipment

the three things that can fail in a transmission.