CALCULATION METHOD FOR MAGNETIC FIELD, CURRENTS, LOSSES, AND LEAKAGE REACTANCE IN THE BAR-TYPE ARMATURE WINDING OF INDIRECTLY COOLED AC ELECTRICAL MACHINE BASED ON STRAIGHTEN MODEL

The paper describes a calculation method for the distribution of the magnetic field, currents, losses, and leakage reactances in the slot parts of bar-type armature winding of indirectly cooled AC electrical machines performed on the base of finite element method of AC magnetic field modeling in a 2D formulation considering electric circuit. The implemented method accounts for the transposition of the strands of the bars along the length of the slot part, the location of the bars in the stator slot, the features of the machine slot geometry and the diagram of armature winding connections, giving the opportunity to simulate different conditions of the winding operation. The method is based on straighten model of generalized electrical machine, which allows to simplify the problem without considerable loss of the solution accuracy. A comparative analysis of the calculation results demonstrates the acceptability of the proposed method. This method could be recommended for calculating various modes, losses and inductive reactances of transposed AC windings in the design and analysis of electrical machines with indirect cooling.