What are core losses (iron losses) in a transformer?
1 Answer
Core losses, also known as iron losses or magnetic losses, are a type of energy loss that occurs in the core material of a transformer or other electromagnetic devices. Transformers are crucial components in electrical power systems, responsible for stepping up or stepping down voltage levels for efficient transmission and distribution of electrical energy. However, during the operation of a transformer, energy is lost in various forms, and core losses are one of them.
Core losses primarily consist of two components: hysteresis loss and eddy current loss.
Hysteresis Loss: This type of loss occurs due to the reversal of magnetization in the transformer's core material as the alternating current (AC) flows through the windings. Every time the direction of the magnetic field changes, the magnetized domains within the core material realign themselves, resulting in the repositioning of magnetic moments. Energy is expended in this process, leading to heat generation and loss of energy. Hysteresis loss is influenced by the properties of the core material, such as its magnetic coercivity and permeability.
Eddy Current Loss: Eddy currents are circulating currents that occur within the core material due to the changing magnetic field induced by the alternating current in the transformer's windings. These currents form closed loops within the core material and create their own magnetic fields. The interaction between these eddy currents and the magnetic field results in energy dissipation in the form of heat. Eddy current loss is affected by the thickness and resistivity of the core material and the frequency of the AC.
Both hysteresis loss and eddy current loss contribute to the overall core losses in a transformer. These losses manifest as heat, and their magnitude depends on factors such as the transformer's design, core material properties, operating frequency, and the level of magnetic flux experienced during operation. Transformers are designed to minimize these losses as much as possible to ensure high efficiency and reduce waste of electrical energy. To achieve this, transformer cores are often made from materials with low hysteresis and eddy current losses, and the design includes features to minimize the flux density variations that contribute to these losses.
Core losses primarily consist of two components: hysteresis loss and eddy current loss.
Hysteresis Loss: This type of loss occurs due to the reversal of magnetization in the transformer's core material as the alternating current (AC) flows through the windings. Every time the direction of the magnetic field changes, the magnetized domains within the core material realign themselves, resulting in the repositioning of magnetic moments. Energy is expended in this process, leading to heat generation and loss of energy. Hysteresis loss is influenced by the properties of the core material, such as its magnetic coercivity and permeability.
Eddy Current Loss: Eddy currents are circulating currents that occur within the core material due to the changing magnetic field induced by the alternating current in the transformer's windings. These currents form closed loops within the core material and create their own magnetic fields. The interaction between these eddy currents and the magnetic field results in energy dissipation in the form of heat. Eddy current loss is affected by the thickness and resistivity of the core material and the frequency of the AC.
Both hysteresis loss and eddy current loss contribute to the overall core losses in a transformer. These losses manifest as heat, and their magnitude depends on factors such as the transformer's design, core material properties, operating frequency, and the level of magnetic flux experienced during operation. Transformers are designed to minimize these losses as much as possible to ensure high efficiency and reduce waste of electrical energy. To achieve this, transformer cores are often made from materials with low hysteresis and eddy current losses, and the design includes features to minimize the flux density variations that contribute to these losses.