Introduction:
A grain-oriented laminated sheet is a specially designed material used in the construction of transformer cores. It is made by annealing a silicon steel alloy in a specific manner to produce a grain structure that allows for better magnetic properties. The use of grain-oriented laminated sheets in transformers helps to reduce hysteresis loss.

Explanation:
Hysteresis loss is a type of energy loss that occurs in transformers due to the magnetization and demagnetization of the core material during each AC cycle. This loss is caused by the lagging of the magnetic field with respect to the changing magnetic flux. The hysteresis loss is proportional to the frequency of the applied voltage and the area enclosed by the hysteresis loop of the core material.

Role of Grain-Oriented Laminated Sheet:
The use of grain-oriented laminated sheets in transformer cores helps to minimize hysteresis loss. This is achieved through the following mechanisms:

1. Grain Orientation: The grain-oriented laminated sheets are carefully designed to have their grains aligned in a specific direction. This orientation allows for the maximum magnetic flux density to be achieved in that direction, resulting in reduced hysteresis loss.

2. Reduced Core Loss: The use of grain-oriented laminated sheets reduces the core loss by minimizing the energy dissipated during each magnetization and demagnetization cycle. This is achieved by reducing the area enclosed by the hysteresis loop of the core material.

3. Efficient Magnetic Path: The grain-oriented laminated sheets provide an efficient magnetic path for the flux generated by the primary winding of the transformer. This reduces the flux leakage and ensures that a larger portion of the flux passes through the windings, resulting in reduced hysteresis loss.

4. Improved Electrical Properties: The grain-oriented laminated sheets have improved electrical properties, such as higher resistivity and lower eddy current losses. These properties further contribute to the reduction of hysteresis loss in the transformer.

Conclusion:
In conclusion, the use of grain-oriented laminated sheets in transformers helps to reduce hysteresis loss. This is achieved through various mechanisms, including the alignment of grains, reduction of core loss, efficient magnetic path, and improved electrical properties. By minimizing hysteresis loss, the efficiency and performance of the transformer are improved.