Open Circuit Tooth Ripple Losses in Slotted Laminated Poles of Electrical Machines with Amortisseur Windings

The results of experimental and theoretical investigations of open circuit tooth ripple losses in slotted laminated poles of rotating electrical machines with amortisseur windings are presented. A laboratory machine model developed for this investigation is described. Both a Poynting vector method based on the electronic multiplication of electric and magnetic fields on the airgap surface of stationary poles and a calorimetric method using integrated area sensors for the rate of temperature rise have been used to measure the losses. Simplified practical formulas have been developed to calculate these losses with sufficient accuracy for design purposes.