Equivalent Electrical Circuit Method for Calculating Circulating Current in Hairpin Windings

This paper utilizes an equivalent electrical circuit methodology to calculate circulating current in distributed hairpin winding configurations. The proposed model is used to examine potential circulating currents arising from manufacturing-related conductor misalignment in a strong symmetric full-pitch 96-slot, 8-pole, 6-layer hairpin stator with a high number of parallel branches. Circulating currents generate additional losses, and understanding this extra source of losses is crucial for satisfying the 1% loss accuracy requirement of highly efficient powertrains. The unbalanced branch currents calculated using the proposed equivalent electrical circuit method are compared with results obtained from a commercial Finite Element Analysis (FEA) software.