This paper describes a calculation method of distribution of the magnetic field, currents and losses in the slot parts of AC machines armature winding bars. The method is based on modeling of AC magnetic field by finite element method in 2D formulation with linked electrical circuit and taking into account the transposition of strands along the length of the bar slot part, the curvature of magnetic core, the location of the bars in the stator slot, the features of the machine slot geometry and the diagram of armature winding connections. The method allows simulating different conditions of the winding operation. A comparative analysis of the calculation results based on a generalized AC electric machine shows the acceptability of the proposed method. This method could be recommended for calculating of the losses of transposed AC windings in the design and analysis of electrical machines.