What is hysteresis loss in electrical machines?
Share
Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Hysteresis loss in electrical machines is the energy lost as heat due to the lag between the magnetic field and the magnetization of the material. When the magnetic material (like the iron in a transformer or motor) is exposed to a changing magnetic field, the magnetic domains inside it don’t align and realign instantly. This delay causes some energy to be dissipated as heat every time the magnetic field changes direction.
You can think of it like trying to push a heavy door back and forth. It doesn’t snap back instantly—you have to exert extra effort each time, and that effort gets wasted as friction. In the case of electrical machines, the “friction” is the resistance of the material to changing its magnetic state. This loss depends on the frequency of the magnetic changes and the properties of the material.
In electrical machines like motors and transformers, there’s a core usually made of iron or some magnetic material. When the machine runs, the magnetic field inside that core keeps changing direction (especially with AC current). But the material doesn’t instantly follow the changes—it’s a bit “lazy,” like when you’re slow to get up in the morning. That lag or resistance to changing direction causes energy loss in the form of heat.
That’s what we call hysteresis loss. It happens every time the magnetic field flips back and forth. To reduce it, engineers use special materials like silicon steel or laminated cores that are better at flipping without wasting too much energy.
So in short:
Hysteresis loss = heat energy wasted because the core resists changing its magnetism direction quickly.