The modern synchronous machines make use of non-directional cold rolled steel.

The construction of modern synchronous machines, like alternators or synchronous motors, extensively uses cold-rolled, non-oriented (CRNO) steel for the core material. This material choice is crucial for several reasons:

1. Reduced Hysteresis Loss: Cold rolling aligns the grain structure of the steel, which, when non-oriented, does not prefer magnetic flux in any particular direction. This uniformity reduces hysteresis loss, which is the energy lost due to the lagging of magnetic domains behind the changing magnetic field.

2. Decreased Eddy Current Loss: The lamination of the CRNO steel into thin sheets, and insulation between these laminations, minimizes the pathways for circulating currents caused by the machine’s alternating magnetic field. These circulating currents, known as eddy currents, can cause significant heating and energy losses if not adequately managed. The lamination process effectively reduces these losses.

3. Improved Permeability: The cold-rolling process improves the magnetic properties of the steel, enhancing its permeability. High permeability in the core material allows for efficient flux linkage, which is vital for the electromagnetic induction process that synchronous machines rely on.

4. Mechanical Strength and Stability: The mechanical strength of CRNO steel is high, meaning it can withstand the physical and thermal stresses encountered during the operation of electrical machines without deforming.

5. Cost-Effectiveness: The process of manufacturing CRNO steel involves less energy and complexity compared to the production