Development of method to calculate the distribution of the magnetic field, currents and losses in transposed bars of armature winding

This paper describes a method to calculate the distribution of the magnetic field, currents and losses in the slot parts of electrical machines armature winding bars. The method is based on finite-element-analysis modelling of the AC magnetic field in 2D formulation with an associated electrical circuit using the ELCUT software suite. The method assumes ideal transposition of the strands along the length of the slot portion of the bar, and considers the features of the machine slot geometry and arrangement of the winding in the armature slots. The electrical circuit simulates the connection of the strands in the armature winding considering their positions along the bar length. A comparative analysis of the results obtained from the dedicated numerical studies allowed to evaluate the impact on the calculation results from different conditions such as the position of transposed strands along the length of the machine and the need to consider the presence of the simulated rotor. The analysis was carried out by comparing the power performances, i.e. the ohmic and stray losses and their ratio. This method could be recommended for calculating of the losses of transposed AC windings in the design and analysis of electrical machines.