How solid-state transformers could help power the AI boom

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How solid-state transformers could help power the AI boom

EXECUTIVE SUMMARY Transformers are a crucial but nearly invisible part of our grid. The devices help efficiently move power across long distances, but they’re complicated and in short supply. And given that their basic design hasn’t changed much for about a century, they could use an upgrade.

执行摘要 变压器是我们电网中至关重要却几乎隐形的一部分。这些设备有助于在长距离内高效传输电力，但它们结构复杂且供应短缺。鉴于其基本设计在一个世纪以来几乎没有改变，它们确实需要升级。

As the world races to meet rising electricity demand from EVs, data centers, and more, researchers and companies are looking to modernize transformers. New, solid-state versions could help relieve some of the supply concerns and make sure the grid can handle the growing pressure.

随着世界竞相满足电动汽车、数据中心等带来的电力需求增长，研究人员和企业正寻求对变压器进行现代化改造。新型固态变压器有助于缓解部分供应担忧，并确保电网能够应对日益增长的压力。

Conventional transformers generally rely on huge amounts of specialized steel alloys and miles of copper wire to do their work of transferring electricity between circuits. Solid-state models, in comparison, combine magnetic components with high-power semiconductors, making them more compact and allowing for more control over the flow of electricity.

传统变压器通常依赖大量的特种钢合金和数英里的铜线来完成电路间的电力传输工作。相比之下，固态模型将磁性元件与大功率半导体相结合，使其更加紧凑，并能对电流实现更精细的控制。

These devices are still in development, and can’t replace all traditional transformers today, especially the largest ones that work at the high voltages necessary for long-distance transmission. But a new generation of transformer technology could be a crucial part of our future grid.

这些设备仍处于开发阶段，目前无法取代所有传统变压器，尤其是那些用于长距离输电所需高电压的大型变压器。但新一代变压器技术可能成为我们未来电网的关键组成部分。

The grid’s backbone Moving electricity through the grid isn’t perfectly efficient: As electricity flows through power lines, some gets lost as heat. How much varies—the higher the voltage, the lower the current, and the less electricity gets lost. So a key function for the grid is stepping voltage up and down.

电网的骨干 通过电网输送电力并非完全高效：当电流流经输电线时，部分能量会以热量的形式损耗。损耗量因情况而异——电压越高，电流越低，电力损耗就越少。因此，电网的一个关键功能就是升压和降压。

Consider, for example, your local solar plant. For that electricity to efficiently travel to your home hundreds of miles away, it needs to reach a higher voltage than what’s generated by the solar plant. Enter transformers.

以当地的太阳能发电厂为例。为了让电力能高效地传输到数百英里外的家中，它需要达到比太阳能发电厂所产生的电压更高的水平。这时，变压器就派上用场了。

In its path from the power plant to your outlets, electricity might go through one transformer at the solar farm and another at a substation nearby, stepping up the voltage twice to reach a high enough level to travel on high-voltage transmission lines. Solar panels also produce direct current (DC) electricity, which needs to be converted to alternating current (AC) via an inverter before it flows into a transformer.

在从发电厂到你家插座的过程中，电力可能会经过太阳能电站的一个变压器和附近变电站的另一个变压器，通过两次升压达到足以在高压输电线上传输的水平。太阳能电池板产生的是直流电（DC），在流入变压器之前，需要通过逆变器转换为交流电（AC）。

Closer to its destination, the voltage will be stepped down again, probably at least twice: once at another substation and again at a smaller transformer in your neighborhood. If you’re in the US, electricity from a solar plant might be converted to AC by an inverter at around 480 volts, get stepped up to 115,000 volts for the transmission lines, and finally get stepped back down to 120 volts and 240 volts for your home.

在接近目的地时，电压会再次降低，通常至少需要两次：一次是在另一个变电站，另一次是在你社区内的一个小型变压器处。如果你在美国，来自太阳能电厂的电力可能会先由逆变器转换为约480伏的交流电，升压至115,000伏以供输电线传输，最后再降压至120伏和240伏供家庭使用。

Conventional transformers do this work using what essentially amount to loops of wire. The core of a transformer is typically made of a special type of steel called grain-oriented electrical steel. Coils of copper wire sit on either end of that core. The number of loops in each coil determines the voltage on either end of the transformer: If there are more loops on the secondary coil than the primary, the voltage steps up, and if there are fewer, it steps down.

传统变压器利用本质上是线圈的结构来完成这项工作。变压器的铁芯通常由一种称为取向电工钢的特殊钢材制成。铜线圈位于铁芯的两端。每个线圈的匝数决定了变压器两端的电压：如果次级线圈的匝数多于初级线圈，电压就会升高；反之，电压就会降低。

When incoming electricity passes through loops on the upstream end of the transformer, that forms a magnetic field in the core. That field induces a voltage in the loops on the other side of the device, which is what allows the energy to continue flowing at a new voltage. This process is called magnetic induction.

当输入电流通过变压器上游端的线圈时，会在铁芯中形成磁场。该磁场在设备另一侧的线圈中感应出电压，从而使能量能够以新的电压继续流动。这一过程被称为电磁感应。

Transformers form the backbone of electricity transmission and distribution, says Srdjan Lukic, a professor of electrical and computer engineering at North Carolina State University. In addition to doing the job of stepping up and down voltage, transformers also often provide what’s called galvanic isolation, meaning there’s no direct electrical path flowing through them. That can help limit disturbances from moving through the grid, improving safety. The problem is that today’s transformers are big and bulky, and they’re also difficult and expensive to replace, Lukic says.

北卡罗来纳州立大学电气与计算机工程教授Srdjan Lukic表示，变压器构成了电力传输和分配的骨干。除了升降压功能外，变压器通常还提供所谓的电气隔离，这意味着没有直接的电流路径流过它们。这有助于限制干扰在电网中的传播，从而提高安全性。Lukic指出，问题在于当今的变压器体积庞大且笨重，而且更换起来既困难又昂贵。

A solid option Solid-state transformers essentially add so-called power electronics—semiconductors that convert and control electricity to the typical blueprint of today’s transformers. While a conventional transformer operates at the frequency of the part of the grid it’s connected to, a solid-state transformer actually controls the frequency of the current.

一个稳健的选择 固态变压器本质上是在当今变压器的典型蓝图上增加了所谓的电力电子设备——即用于转换和控制电力的半导体。传统变压器在其所连接的电网频率下运行，而固态变压器实际上可以控制电流的频率。

Typically, a solid-state transformer first converts incoming AC power from the grid to DC power, and then to a higher-frequency AC power using switches made of a semiconductor like silicon carbide. From there, a magnetic component changes the voltage. Because the advanced semiconductors allow transformers to exert so much control over the frequency and stability of the current, the magnetic core can be much smaller than in a conventional transformer. Some come in at roughly one-tenth the size but have the same capacity, Lukic says.

通常，固态变压器首先将来自电网的交流电转换为直流电，然后利用碳化硅等半导体制造的开关将其转换为更高频率的交流电。随后，磁性元件改变电压。由于先进的半导体使变压器能够对电流的频率和稳定性进行极大的控制，其磁芯可以比传统变压器小得多。Lukic说，有些变压器的体积仅为传统变压器的十分之一左右，但容量却相同。

Finally, additional power electronics convert the electricity from high-frequency AC to its required form—generally back to DC power and finally to lower-frequency AC. Today, stepping voltage up and down is many transformers’ only job. But solid-state transformers can do much more. They absorb the jobs of devices like rectifiers and inverters (which convert AC to DC power and vice versa), shrinking the total footprint of the electrical equipment and potentially cutting the amount of power lost in the system.

最后，额外的电力电子设备将高频交流电转换为所需的形式——通常是先转回直流电，最后再转为低频交流电。如今，升降压是许多变压器的唯一工作。但固态变压器能做的远不止于此。它们承担了整流器和逆变器（负责交流电与直流电互转）等设备的工作，缩小了电气设备的总占地面积，并可能减少系统中的电力损耗。

In August, the New York Power Authority and the Electric Power Research Institute (EPRI) tested a one-megawatt solid-state transformer under realistic utility conditions at EPRI’s test site. The device was built in Lukic’s lab, and it was the first such test for a transformer of that capacity, he says. The prototype was roughly 98% efficient—meaning it lost only 2% of the energy fed in. An equivalent conventional transformer and rectifier, by comparison, would be about 96% efficient together, Lukic says. A difference of 2% might seem small, but it is significant, since it means the solid-state transformer could cut power.

8月，纽约电力局和电力研究所（EPRI）在EPRI的测试点对一台一兆瓦的固态变压器进行了实际公用事业条件下的测试。Lukic表示，该设备是在他的实验室中制造的，这是此类容量变压器的首次此类测试。该原型的效率约为98%，意味着输入的能量仅损耗了2%。相比之下，同等的传统变压器和整流器组合的效率约为96%。2%的差异看起来很小，但意义重大，因为这意味着固态变压器可以减少电力损耗。