Electrical Technology, Volume 1

10

Hysteresis

OBJECTIVES

In this chapter you will learn about:

• The lagging of flux, in the core of the electromagnet, behind the magnetizing force
• The shape and size of hysteresis loops of different magnetic materials and its influence on their performance
• Problems on calculation of hysteresis loop
• Eddy currents: their origin and minimization
• Eddy current losses and their contribution to core loss
• Calculation of eddy current loss and hysteresis loss
• Separation of hysteresis loss and eddy current loss from core loss
• Problems on separation of losses
• Plotting core losses
• The significance of the contour of the B-H curve
• Residual magnetism, remanence, coercive force, coercivity, retentivity, etc.
• The influence of the thickness of laminations