AMORPHOUS CORE FOR LOW LOSS TRANSFORMATION

Generally, two main types of losses exist during an electrical power transformation and are also inherent in every transformer. We have the load loss also known as the winding loss where this type of loss depends on the loading of the transformer, the higher the load, the higher the loss that it can generate. Also, we have the no-load loss also known as the core loss where this is type of loss is constant in every transformer regardless it is fully loaded or no-load at all.

The consistency of the core loss creates a huge effect to the system’s loss especially in a large electric utility. Although transformers are relatively efficient devices, often they have an efficiency of 99% during its operation; they still lose a significant amount during its use.

In the modern electrical practice, the use of a new kind of material in the transformer application produced a huge effect in the reduction of loss in a transformer operation; the amorphous core. Amorphous metals are made of alloys which have no atomic order. The lack of systematic structure has given them the additional name metallic glasses. The first amorphous metal transformers (AMTs) were produced in 1981. They were the result of an extensive study carried out by Luborsky of the General Electric Co, USA in 1978.

Amorphous Metal Transformer (AMT) is a type of energy efficient transformer found on electric grids. The magnetic core of this transformer is made with amorphous metal (e.g. Metglas), which is easily magnetized / demagnetized. Typically, core loss can be 70–80% less than its traditional counterpart. This leads to a reduction of generation requirement and, when using electric power generated from fossil fuels, less CO2 emissions. It has been widely adopted by large developing countries such as China and India where energy conservation and CO2 emission reduction have been put on priority. These two countries can potentially save 25–30 TWh electricity annually, eliminate 6-8 GW generation investment, and reduce 20–30 million tons of CO2 emission by fully utilizing this technology.

The core of the majority of today's transformers is made of CRGO steel. When this is replaced by amorphous metal the core loss of the transformer can be reduced by as much as 75%. Although first costs are higher than that for a standard transformer, the long term benefits of the investment are compelling. Amorphous metal in transformers has been a breakthrough in the quest for loss reduction in power system application and energy efficiency.

As one of the major programs to improve grid efficiency, China has started to install amorphous metal transformers in a number of energy intensive provinces since 2005. Over 20,000 MVA of such transformers are installed every year. This movement has also led to the successful development and production of amorphous metal ribbon in China.

References: Wikipedia.org, wilsonpowersolutions.co.uk