Why is the stator core built up of laminations?

The stator core of electric machines, such as motors and generators, is built up of laminations to reduce eddy current losses. Eddy currents are circulating currents that are induced in the core due to the alternating magnetic field. These currents flow perpendicular to the primary direction of the magnetic field and can cause significant power losses and heat generation within the core material. By laminating the core, which means constructing it from thin sheets of electrical steel insulated from each other, the path for eddy currents is restricted. This greatly reduces the area available for these currents to flow, thereby reducing the losses and heat they generate. The laminations are typically coated with an insulating material to ensure that they are electrically separated from one another. This design consideration is crucial for the efficiency and performance of electric machines.