Estimation of Eddy Current Loss in Semi-Closed Slot Vertical Conductor Permanent Magnet Synchronous Machines Considering Eddy Current Reaction Effect

This paper presents an analytical methodology based on subdomain field model to calculate eddy current loss in vertical conductor windings (VCWs) of surface mounted, radial flux, permanent magnet (PM) machines considering the current penetration effect. The proposed model can be used with any slot-pole combination including fractional slot machines having VCW. Initially, the model solves the two-dimensional problem based on the Laplace's and Poisson's equations using the separation of variables technique for each of the subdomains: PM, airgap, slot opening, and slot. Then, based on that obtained solution, the eddy current reaction field in the slot is calculated by solving complex Helmholtz's equation. The validity and accuracy of the model is verified using finite-element (FE) analysis. The limitations of analytical method are discussed.