什么是电？

Ben Franklin began exploring electricity using a metal key attached to a kite during a thunderstorm—not a safe activity by today’s health and safety standards.

His theory was that storm clouds hold static electricity, and that lightnings are discharges of static electricity. Lightning would strike the key and electrify it, demonstrating that lightning and electricity are the result of the same phenomenon. He had the right idea, that lightning is the result of electrons traveling from the clouds to the ground, but he lacked the scientific concepts to fully express that idea.

His mantle was taken up and the 19th century saw rapid progress in electrical science, electrical engineering, andpower generation技术。

电力开拓者亚历山大·格雷厄姆·贝尔（Alexander Graham Bell），尼古拉斯·特斯拉（Nicolas Tesla），沃纳·冯·西门子（Werner von Siemens）和更多人，有助于将电力从科学的好奇心转变为生活的重要组成部分。其中一些先驱者在此过程中创造了工业帝国。其中包括托马斯·爱迪生（Thomas Edison）和乔治·韦斯汀（George Westinghouse）。爱迪生（Edison）和西屋（Westinghouse）也是工程史上最迷人的情节之一：电流战争。我们会回到这一点。

电是一个form of energy并由导电材料中的电子流组成。

Electrons are particles that are negatively charged and surround the atom. The nucleus of an atom contains positively charged particles called protons and particles with no charge called neutrons. Normally, an atom can only have as many electrons as it has protons. So, when the flow of electricity bumps an electron onto another atom, that is one too many electrons for the receiving atom. So, another electron is bumped to yet another atom. This is how electricity flows.

电力是如何制造的？

电力是由旨在设置电子流动并保持该流量的机器产生的。这通常是由发电机来完成的。kpl竞猜推荐还有其他发电的方法。太阳能电池板和电池是其他方法。

发电机需要旋转运动，通常由某种涡轮机或发动机提供。旋转运动被转移到发电机的转子上。在发电机内部，转子会产生磁场。当转子旋转时，磁场也旋转。旋转磁场会激发位于发电机静态部分的铜导体中的电子，这就是产生电流的原因。您可以将其视为磁场，直到它们开始移动，直到它们开始移动。电流通过铜导体从发电机，电线和发电厂传播。

Where does electricity come from?

Let’s answer this question this backward.

在您的房屋中轻弹开关，灯打开。我们每天要做数十次，而无需考虑到底会发生什么，或者是什么样的电气系统使它成为可能。

让我们回溯电力片刻。电力通过服务入口进入电动面板的房屋。csgo菠菜网roll服务入口csgo菠菜网roll连接到高架电源线上的低压电缆，该电源线本身连接到了杆安装的变压器。杆式安装的变压器连接到中型电压顶部线路，并连接到所谓的分销网络，该网络连接了特定区域内的本地电力用户。

分销网络通过变电站连接到运输网络。运输网络由高电压线组成，旨在在巨大的距离内传输大量电力。这些电力线导致发电的发电厂。

想想电流，例如流过管道的水。在管道的开头，大约几百英里之外，水压极高。随着靠近社区和房屋的距离，压力降低到更易于管理的压力。这就是为什么在途中的每个步骤中都有变电站和变压器可降低电力的电压。

什么是可再生电力？

Renewable electricity is simply the electricity generated using可再生能源来源。太阳能，风能和水力是产生可再生电力的三种最受欢迎​​的方法。

Demand for renewable electricity has been on the rise for two key reasons. The first is the affordability. Solar panels and wind turbines have become better and cheaper over the years. The second reason is around environmental concerns. The tolerance for the emissions associated to fossil power plants is rapidly declining. This drives the trend in replacing fossil power plants with renewable energy resources.

What are AC and DC electricity?

替代电流（AC）和直流电流（DC）是电流可以在电路中流动的两种不同方式。

直流以恒定速率流动，并且始终朝着相同的方向流动。交流以可变速率流动，其流动方向经常变化。

当我们说北美的电力供应为60 Hz时，这意味着AC流的方向每秒变化60次。将AC视为运动型快速赛车中的曲轴。它有多个气缸，推动曲柄轴移动汽车，但气缸并未同时推动曲轴。他们一起推动汽车，这种运动感觉像是持续的运动。

现在将DC视为手钻。该钻头将恒定的运动（恒定力量）带给其所做的任何任务。

In the early days of electrification, DC and AC were both seen as valid ways to generate, transport, distribute and consume electricity. This takes us back to Edison and Westinghouse.

爱迪生设想了基于直流电的电气系统。Westinghouse支持AC系统的开发。他们的问题在于，AC和DC系统是互斥的，因此必须占上风，另一个必须丢失。这导致了一场苦难的竞争，这在历史史上。

最终，AC成为主要的电力类型，因为它更容易运输和分发从发电厂到变电站，再到房屋和企业。

Fragments of Edison’s DC electrical system remained in New York City well into the 20th century, serving for example old buildings that had DC elevators or the subway system, whose trains were also running on DC. The last DC service customer in Manhattan, a building on 40th Street, was disconnected as late as 2007.

有趣的是，DC输电线路正在某些应用中卷土重来。例如，对于将海上风电场带回陆地产生的电力的海底电缆来说，它们是一个共同的选择。The reason that DC lines can connect to the AC network is that we now have power electronics that can convert electricity between DC and AC with minimal losses—power electronics hadn’t been invented in the 19th century, so Edison and Westinghouse didn’t have that option.

AC, DC and renewable electricity

Interestingly, the rise of可再生能源从太阳能和风资中，引起了DC电力的兴趣。有几个原因。

第一个原因是，对于将海上风电场带回陆地产生的电力的海底电缆来说，DC往往是一个不错的选择。这些直流连接有时被称为HVDC线，如高压直流线所示。

Another reason is the fact that PV panels can only produce DC electricity.

第三个原因是增加用途刻度电池储能系统的使用结果通常与光伏面板一起构建以帮助减轻其可变性，并且像光伏面板一样，只能产生直流电。所有这些DC元件都使用可以将DC和AC之间的电力转换为最小损失的DC和AC之间的电力电子设备，该元素连接到具有AC电力的宽阔电网。

Power Electronics尚未在19世纪发明，不幸的是，对于Edison和Westinghouse而言，这一选择不可让他们调和。