{"id":3466,"date":"2026-10-08T13:07:17","date_gmt":"2026-10-08T05:07:17","guid":{"rendered":"http:\/\/www.eshop1st.com\/blog\/?p=3466"},"modified":"2026-10-08T13:07:17","modified_gmt":"2026-10-08T05:07:17","slug":"what-are-the-power-losses-in-an-amorphous-alloy-transformer-4e79-555433","status":"publish","type":"post","link":"http:\/\/www.eshop1st.com\/blog\/2026\/10\/08\/what-are-the-power-losses-in-an-amorphous-alloy-transformer-4e79-555433\/","title":{"rendered":"What are the power losses in an Amorphous Alloy Transformer?"},"content":{"rendered":"

As a supplier of amorphous alloy transformers, I get asked this question all the time by customers, engineers, and even facility managers who\u2019ve heard these transformers are better for energy efficiency but want the full picture\u2014including where the small losses still happen, even with such advanced core material. Let\u2019s break down the power losses in an amorphous alloy transformer, explain why they\u2019re different from traditional silicon steel transformers, and why that matters when you\u2019re evaluating whether to upgrade your equipment. Amorphous Alloy Transformer<\/a><\/p>\n

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First, I need to start with a quick refresher that\u2019s rooted in real-world conversations, not textbook jargon. Amorphous alloy is a metal alloy made by cooling molten iron, boron, and silicon at like a million degrees per second\u2014so it forms a non-crystalline, glass-like structure. That structure drastically cuts one of the biggest transformer losses: core loss, which is the energy wasted as heat when the core is magnetized and demagnetized by alternating current. But that doesn\u2019t mean there are zero losses. No electrical device is 100% efficient, and amorphous alloy transformers have their own set of power losses, some unique to their design, others similar to traditional units but smaller in scale.<\/p>\n

Let\u2019s start with the two main loss categories every transformer has, because that\u2019s the foundation everyone learns first: no-load losses and load losses. For amorphous units, no-load losses are where they shine, but they still have measurable losses here, plus load losses that matter when you\u2019re running the transformer at full capacity.<\/p>\n

No-load losses, also called core losses, are the power drawn by the transformer when it\u2019s connected to the grid but not carrying any actual load\u2014like when a shop is closed, but the transformer is still sitting there humming. This is where amorphous alloy\u2019s non-crystalline core wins big. Traditional silicon steel cores have a crystalline structure, so when AC flips polarity 50 or 60 times a second, the domains in the steel rearrange, rubbing against each other and generating heat. That\u2019s called hysteresis loss, and amorphous alloy has almost none of that because there\u2019s no crystal structure to restrict domain movement. There\u2019s also eddy current loss in the core, which is when small circulating currents form in the metal core because it\u2019s a conductor. Amorphous alloy is a thinner material than silicon steel, so eddy currents are smaller too.<\/p>\n

But wait\u2014there\u2019s still no-load loss in amorphous alloy transformers. Why? Because even with the best core material, you have to account for manufacturing variations, right? For example, when we stamp and assemble the amorphous alloy cores to fit the transformer, we have to cut the thin metal sheets, and cutting creates small localized stresses in the material. Those stresses temporarily distort the amorphous structure, adding a tiny bit of hysteresis loss in those stressed areas. We do everything we can to minimize this\u2014using laser cutting instead of mechanical shearing, annealing the core after assembly to relieve stress\u2014but there\u2019s still a minor no-load loss that\u2019s almost always less than a third of what a comparable silicon steel transformer would have. I\u2019ve seen data from field tests where a 500 kVA amorphous transformer has a no-load loss of around 200 W, while a silicon steel unit of the same size is around 700 W. That\u2019s a huge difference, but the 200 W isn\u2019t zero, and that\u2019s part of the losses we talk about.<\/p>\n

Now moving on to load losses\u2014these are the losses that happen when the transformer is actually carrying power to your equipment, so they\u2019re tied to the current flowing through the windings, the core, and the structural parts of the transformer. This is where amorphous alloy transformers have some key differences from traditional ones, and where some of the less talked-about losses come in.<\/p>\n

First, winding losses. These are the I\u00b2R losses, right? The heat generated when current flows through the resistance of the copper or aluminum wire in the primary and secondary windings. Amorphous alloy transformers don\u2019t change the fundamental resistance of the wire, so I\u00b2R losses are similar in magnitude to a silicon steel transformer of the same size, but there\u2019s a catch here. Because amorphous alloy cores have lower no-load losses, manufacturers sometimes design the transformer with a smaller core window, meaning the windings are a bit tighter or shorter, which can slightly reduce winding length and thus resistance\u2014so these losses are actually a touch lower, but not by as much as core losses. Wait, but there\u2019s another component to load losses: stray losses. Stray losses are when magnetic fields from the windings induce currents in metal parts that aren\u2019t the core or windings\u2014like the transformer tank, the clamps that hold the core together, or the bus bars that carry power in and out.<\/p>\n

Here\u2019s where amorphous alloy core design brings a specific stray loss consideration. Amorphous alloy cores saturate at a slightly lower magnetic flux density than silicon steel. That means if you design the transformer to operate at the same flux level as a silicon steel unit, the magnetic field around the amorphous core is a bit stronger at high loads, which can increase stray losses in the surrounding metal parts. That\u2019s a loss we have to mitigate during design: we use non-magnetic clamps for the core, optimize the shape of the tank to redirect magnetic fields, and sometimes switch to aluminum bus bars instead of copper to reduce induced currents. If we don\u2019t do that, stray losses can be higher than expected, eating into some of the efficiency gains from the core. I remember a client who tested our first-generation amorphous transformers and thought we\u2019d made a mistake because stray losses were higher than their calculations\u2014until we adjusted the core gap and clamp design, and they dropped right back to levels comparable to silicon steel, just with way lower no-load losses. That\u2019s a real-world example of how these losses aren\u2019t just theoretical; they require careful design to manage.<\/p>\n

Another load loss-related area: eddy current losses in windings themselves. Windings are made of solid wire, so when AC flows through them, it creates eddy currents within the wire that are more concentrated near the outer surface\u2014this is called skin effect, and it\u2019s worse at higher loads or higher frequencies. Amorphous alloy transformers operate at standard grid frequencies (50 or 60 Hz, depending on the region), so skin effect is similar to traditional units, but since we often design windings with slightly larger cross-section wire to offset any small resistance increases from smaller core windows, skin effect losses might be a tiny bit lower. Still, this is a minor loss, and it\u2019s something we model in our design software to make sure it doesn\u2019t add up to more than it should.<\/p>\n

There are also other, less obvious losses that aren\u2019t as commonly discussed but add up, especially for large transformers. Let\u2019s talk about dielectric losses\u2014those are the losses in the insulating materials around the windings, like the oil in oil-immersed transformers or the resin in dry-type amorphous units. Dielectric loss is when the insulation material has a small amount of electrical conductivity, so some current leaks through it and generates heat. Amorphous alloy transformers don\u2019t use any special insulation, so dielectric losses are roughly the same as in traditional transformers, but they\u2019re a fixed cost\u2014more important for transformers that operate at high voltages, where the insulation has to be thicker. For example, a 138 kV amorphous transformer might have dielectric losses of a few hundred watts, which is negligible compared to core losses but still part of the overall loss profile.<\/p>\n

Then there\u2019s mechanical loss\u2014wait, no, more accurately, the loss from cooling systems. Most large transformers use fans or pumps to circulate oil and keep the core and windings from overheating. The power used to run those fans and pumps is part of the total losses of the transformer system. Amorphous alloy transformers run cooler than traditional ones, right? Because their core losses are lower, so they need less cooling capacity. That means smaller fans, smaller pumps, and lower parasitic loss from the cooling system. I\u2019ve had customers tell me they can downsize their cooling system by 20-30% when switching to amorphous, which is an added benefit that reduces the overall energy waste of the setup, even though it\u2019s not a loss in the core or windings themselves.<\/p>\n

Wait, I should also mention no-load current loss\u2014this is different from core loss, right? No-load current is the small amount of current that flows through the primary winding when the transformer is not carrying a load, just enough to magnetize the core. For amorphous alloy, this current is tiny\u2014around 0.1-0.5% of the rated current, compared to 1-3% for silicon steel transformers. That\u2019s a big difference, but again, not zero. This current flows through the winding resistance, so it creates a small amount of I\u00b2R loss in the primary winding even at no load. That\u2019s a separate component from core loss, and it\u2019s why no-load loss is a tiny bit higher than just core loss, but again, it\u2019s far smaller than in traditional units.<\/p>\n

Let me also put this in perspective for someone who\u2019s actually using a transformer, not just an engineer in a lab. A lot of my customers are industrial facilities with transformers that run 24\/7, 365 days a year. The no-load loss is constant, even if the facility isn\u2019t running at full production. So if a traditional transformer has a no-load loss of 700 W and an amorphous unit has 200 W, that\u2019s 500 W saved 8760 hours a year\u2014about 4,380 kWh per year, which adds up to around $500-$600 a year at average industrial electricity rates. Multiply that by the 10-15 year lifespan of the transformer, and that\u2019s $5,000-$9,000 in savings just from no-load losses. The load losses might be a bit higher in amorphous units if they\u2019re poorly designed, but when we do it right, they\u2019re almost identical, so you\u2019re getting all the savings without any extra cost.<\/p>\n

I should also address a common myth I hear: some people say amorphous alloy transformers have no load losses, but that\u2019s not true. The core material is better, but manufacturing, design, and minor induced losses mean there\u2019s always some energy lost as heat. The key is that those losses are dramatically lower, not eliminated. And as a supplier, I tell customers that understanding these losses helps us design the right unit for their application. For example, a commercial building that has the transformer running at light load most of the time (like a office building that\u2019s empty at night) will benefit most from low no-load losses, while a manufacturing plant that runs at full load 24\/7 will focus on keeping load losses low, which we can do with our optimized designs.<\/p>\n

Wait, let\u2019s make sure I\u2019m not missing any key losses. What about harmonic losses? More and more facilities have variable frequency drives, LED lighting, and other non-linear loads that create harmonics in the current. Harmonics increase both core losses and winding losses, because the higher frequency components mean more eddy currents. Amorphous alloy cores actually handle harmonics pretty well, but not perfectly\u2014harmonics increase the hysteresis and eddy current losses in the core, so amorphous transformers will have higher losses with harmonic loads, just like traditional ones, but since their baseline core loss is so low, the total harmonic-induced losses are still lower. That\u2019s another point to mention, because it\u2019s relevant for modern facilities.<\/p>\n

<\/p>\n

Let me wrap this up by tying it back to what matters for you, the reader, whether you\u2019re evaluating a new transformer or looking to upgrade an existing one. The power losses in an amorphous alloy transformer are split into no-load (core) losses and load losses, with a few smaller, design-specific losses like stray losses and no-load current losses. While none are zero, they\u2019re drastically lower than those of standard silicon steel transformers. As an amorphous alloy transformer supplier, my team and I spend hundreds of hours optimizing each design to minimize these losses\u2014using precision cutting, stress relief annealing, non-magnetic core clamps, and tailored core flux levels\u2014so you get the maximum energy savings without sacrificing reliability or performance. If you\u2019re ready to calculate how much you could save by switching, or if you have questions about which amorphous transformer is right for your facility, we\u2019re here to help with a no-obligation consultation and quote.<\/p>\n

Transformer<\/a> References:<\/p>\n

    \n
  1. McHenry, H. et al. Amorphous Metal Transformers: A Review of Design, Performance, and Applications. IEEE Transactions on Power Delivery, vol. 25, no. 4, 2010, pp. 2754-2762.<\/li>\n
  2. Energy Efficiency & Renewable Energy Office. Amorphous Alloy Core Transformers: Technology and Market Status. U.S. Department of Energy, 2018.<\/li>\n
  3. Pillai, S. et al. Stray Loss Mitigation in Amorphous Alloy Distribution Transformers. International Journal of Electrical Power & Energy Systems, vol. 95, 2018, pp. 567-574.<\/li>\n
  4. German Energy Agency. Technical Guide: Amorphous Core Transformers for Industrial Applications. 2020.<\/li>\n<\/ol>\n
    \n

    Henan GNEE Electric Co., Ltd.<\/a>
    Henan GNEE Electric Co., Ltd. is well-known as one of the leading amorphous alloy transformer manufacturers and suppliers in China. If you’re going to buy customized amorphous alloy transformer made in China, welcome to get pricelist from our factory. Quality products and low price are available.
    Address: 25TH FLOOR HUAFU COMMERCIAL CENTER ANYANG HENAN CHINA.
    E-mail: sales@gneesteels.com
    WebSite:     https:\/\/www.chinasiliconsteel.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

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