Energy Efficiency Transformers

Energy Efficiency Transformers

Q. State and explain the features of amorphous core transformers which result into energy conservation.

Amorphous Core Transformer

Amorphous core transformers or amorphous metal transformer is a type of energy efficient transformer.
Amorphous transformer is an equipment to reduce transmission and distribution losses greatly.
With improvement of electric steel (silicon steel), loss of transformer is reduced to 50% of that of trans used earlier.
It is possible to achieve even higher efficiency using new better magnetic materials. Amorphous transformer is modern example and uses amorphous metal for the core.
This core can be easily magnetized and demagnetized.
Core loss by this metal can be reduced to 70-80% than traditional transformer.
This results into low electricity production and less CO₂emission at generating plants using coal.
Energy loss due to heat or vibration from the core is reduced.
Amorphous transformer uses metallic glass-alloy for the core.
Reduction in energy loss over conventional transformers is about 70%.
They have increased efficiencies even at low loads i.e. 98.5% efficiency at 35 % load.
They are costlier than conventional iron core transformers, but the overall benefit towards energy savings will compensate for the higher initial investment
At present they are available upto 1600 kVA rating.

Limitations :

(a) Small thickness of core stampings. Limitations of energy efficient transformers are as follows :

(b) Large core size. (c) Large conductors. (d) Hardness of strip than CRGO strips. (e) Big tank. (More insulating oil. (9) Large overall cost.

(a) Amorphous metal :

Amorphous metal is an alloy rather than a pure metal. They are produced by using rapid solidification technology, where molten metal is cast into thin solid ribbons by cooling at a high rate.
It is a magnetic material having high permeability due to no crystalline magnetic anisotropy (states having different sizes or characteristics along different axes).
The material in which such disordered structure is produced directly from the liquid state during cooling are called glasses and hence amorphous metals are commonly referred to as metallic glasses or glassy metals.
They can be produced by other methods such as physical vapour deposition, solid state reaction, iron irradiation, metal-spinning or mechanical alloying.
These cores allow, smaller, lighter and more efficient design in many high frequency applications for inverters, U.P.S. (uninterrupted power system), adjustable speed drives etc.
Nano-crystalline amorphous metal offers saving in size, core material and labour for various application.
They have superior magnetic qualities, such as lower core loss compared with conventional crystalline or magnetic materials. The cores of this type offer superior design alternatives.

Following are the features of amorphous transformer which in energy conservation.

Sr. No.	Features of amorphous transformer	Energy Conservation
1.	Flux density of saturation = 1.55 T	So low magnetic losses but size of transformer increases.
2.	Low field magnetization	It results in low hysteresis losses.
3.	Thickness of this metal is very small 0.025 mm.	Eddy current losses are lesser.
4.	High electrical resistivity of amorphous transformer.	Eddy currents suppressed resulting low eddy current losses.
5.	This material has high permeability as its structure in non-crystalline (easy magnetize/ Demagnetize).	Core losses are reduced by 70 to 80%.

Advantages of amorphous transformers are :

(i) Iron losses : (a) Eddy current, (b) Hysteresis are very low.

(ii) Temperature rise in working condition is very low.

(iii) Magnetizing current is very small.

(iv) Energy saving by about 70%.

(v) Its reliability is higher.

(vi) Requires less maintenance.

(vii) Reduce CO, emission.

(viii) Reduction in fossil fuel consumption.

(ix) Overload capacity is much more.

(x)Excellent short circuit capacity.