100 Blackout!-Low

Blackout! FOCUS Question What are blackouts, and why do they occur?

停电!什么是停电，为什么会发生?

Lights Out! What do you do if the power goes out? Light candles? Carry a flashlight It can be kind of exciting when the electricity is out for a few minutes but imagine if it goes out for days or even weeks! A long-lasting widespread power outage is a blackout, and it gets old pretty fast. Some blackouts are caused by severe weather that takes down power lines. Other blackouts happen due to periods of high demand for electricity. Computers that run power systems are also vulnerable to technical glitches and cyber attacks. A cyber attack happens when a computer virus is used to shut down or disable one or more power plants. During a blackout, an entire country can lose power.

熄灯!如果停电了你该怎么办? 点燃蜡烛吗?带一个手电筒，停电几分钟是令人兴奋的，但想象一下，如果停电几天甚至几周!长时间的大范围停电被称为停电，而且它很快就会过时。 一些停电是由于恶劣天气导致电线断裂造成的。 其他停电是由于电力需求高的时期。 运行电力系统的计算机也容易受到技术故障和网络攻击的影响。 当计算机病毒被用来关闭或禁用一个或多个发电厂时，就会发生网络攻击。 在停电期间，整个国家都可能断电。

Blame It on the Grid The system that delivers electricity to your home is called a grid. Electrical grids are made up of power plants that produce electricity and countless miles of power lines, or transmission lines. To get from the power plant to your home, electricity traveling through the grid is high voltage. Transformers in the grid raise the voltage so it can travel long distances. Transmission lines deliver the electricity to additional transformers that lower the voltage and make it safer for neighborhoods. Distribution lines carry the electricity to houses. The trouble with many power grids around the world is that they are getting old, but the demand for electricity is rising. When parts of a grid fail, blackouts can occur. Word Wise Voltage is the force of an electrical current.

把电力输送到你家的系统叫做电网。 电网由生产电力的发电厂和数不清的电线或传输线组成。 从发电厂到你家，通过电网的电是高压的。 电网中的变压器提高电压，使其可以传播很远的距离。 输电线路将电力输送到额外的变压器，从而降低电压，使社区更加安全。 配电线路将电力输送到各家各户。 世界上许多电网的问题是它们正在老化，但对电力的需求却在上升。 当部分电网故障时，可能会发生停电。 电压是电流的力。

Blame It on the Weather Some of the worst blackouts are caused by huge storms. Strong winds, heavy rains, and falling tree limbs can knock down power lines. After Hurricane Katrina in 2005, electricity was out for more than three weeks in several U.S states. In 2012, Hurricane Sandy left people from Maine to Virginia without power for nearly two weeks. Winter storms can also cause blackouts. Snow and ice coat power lines, and the added weight can bring them down. Ice storms in the United States in 2008 caused blackouts from Maine to Pennsylvania and even as far south as Louisiana. A 2011 snowstorm left people in Connecticut and Massachusetts without power for more than a week. It takes time for utility crews to repair power lines and restore electricity.

一些最严重的停电是由巨大的风暴引起的。 强风、暴雨和倒下的树枝都可能吹倒电线。 2005年卡特里娜飓风过后，美国几个州停电超过三周。 2012年，飓风桑迪(Sandy)让从缅因州到弗吉尼亚州的人们断电近两周。 冬季风暴也会导致停电。 冰雪覆盖电线，增加的重量会使电线下降。 2008年美国的冰暴造成了从缅因州到宾夕法尼亚州，甚至远至路易斯安那州的停电。 2011年的一场暴风雪使康涅狄格州和马萨诸塞州的人们停电超过一周。 公用事业人员修复电线和恢复供电需要时间。

Intentional Outages Sometimes electric companies cause blackouts on purpose by shutting off small sections of the grid, one at a time, to prevent a failure of the entire system. These are called rolling blackouts. In 2011, during a rare cold snap in Texas, people were using a lot of electricity to heat their homes. This high demand led to rolling blackouts for two days. Brownouts happen when the electricity continues to flow but the voltage drops. This causes lights to dim and can affect other electric devices. Electric companies use brownouts to reduce the load on power plants and prevent blackouts, but sometimes brownouts occur because of storms or system glitches.

有时电力公司故意停电，一次切断一小部分电网，以防止整个系统出现故障。 这被称为滚动停电。 2011年，在德克萨斯州罕见的寒流期间，人们使用大量的电力来供暖。 如此高的需求导致了连续两天的停电。 当电力持续流动但电压下降时，就会发生限电。 这会导致灯光变暗，并影响其他电子设备。 电力公司利用限电来减少发电厂的负荷，防止停电，但有时停电是由于风暴或系统故障。

A Year of Big Blackouts In August 2003, six states and parts of Canada went dark in the Great Northeast Blackout. High electricity use on a hot day caused a wire in a transmission line to heat up. The line's covering melted and weakened, then it snapped when a tree limb hit it. An alarm meant to alert workers of the outage never went off, so the same thing happened to other lines. In the end, fifty million people were without power for about two days. In September of that same year, parts of Switzerland and much of Italy lost power. Storms damaged a transmission line that brings electricity from Switzerland to Italy. Suddenly, there was increased demand on the lines that were still working. They became overloaded and failed as well.

2003年8月，加拿大东北部发生大停电，6个州和部分地区陷入黑暗。 大热天的高用电量导致输电线路上的电线发热。 绳子的覆盖物融化变弱，然后被树枝撞断了。 用来提醒工人停电的警报器从来没有响过，所以同样的事情发生在其他线路上。 最后，5000万人停电大约两天。 同年9月，瑞士部分地区和意大利大部分地区断电。 风暴破坏了一条从瑞士到意大利的输电线路。 突然之间，仍在工作的线路的需求增加了。 他们负担过重，也失败了。