Core losses occur in a transformer primarily due to two reasons: hysteresis loss and eddy current loss. Hysteresis loss occurs because the core material (typically made of silicon steel) undergoes repeated magnetization and demagnetization cycles as the alternating current flows through the transformer windings. Each cycle causes energy to be dissipated as heat due to the inherent magnetic properties of the core material, leading to hysteresis losses. Eddy current loss, on the other hand, occurs due to the formation of circulating currents (eddy currents) within the core material itself. These currents induce resistive heating, contributing to additional energy losses.
The two causes of power loss in the core of a transformer are hysteresis loss and eddy current loss. Hysteresis loss occurs because the core material exhibits a lag in magnetization when subjected to alternating magnetic fields. This lag results in energy dissipation as heat during each magnetic cycle. Eddy current loss, on the other hand, arises from the circulation of currents within the core material induced by the changing magnetic field. These currents encounter resistance in the core material, leading to further energy dissipation in the form of heat.
Core losses in a transformer are termed constant losses because they remain relatively constant regardless of the load on the transformer. These losses depend primarily on the core material’s magnetic properties and the operating frequency. In contrast, copper losses (or winding losses) vary with the load current flowing through the transformer windings. Copper losses result from the resistance of the copper conductors used in the windings and increase as the load current increases. This distinction between constant core losses and variable copper losses is essential in transformer design and efficiency calculations.
Core loss and copper loss are two distinct types of losses in a transformer. Core loss refers specifically to the energy dissipated as heat within the transformer’s core due to hysteresis and eddy currents. It is an inherent loss that occurs continuously during transformer operation, regardless of the load conditions. Copper loss, also known as winding loss or I²R loss, refers to the energy dissipated as heat in the transformer windings due to the resistance of the copper conductors. Copper losses vary with the square of the load current and contribute to the overall efficiency reduction of the transformer.
Core loss in a transformer refers to the power that is dissipated as heat within the transformer core due to hysteresis and eddy current losses. Hysteresis loss occurs because the core material undergoes magnetic reversals as the alternating current flows through the windings, resulting in energy dissipation. Eddy current loss arises from circulating currents induced within the core material by the changing magnetic field. Together, these losses represent the energy that is not transferred to the load but instead converted into heat within the transformer’s core, affecting its overall efficiency and performance.