Circuit Network Model of Stator Transposition Bar in Large Generators and Calculation of Circulating Current

Calculation of circulating current in transposition bars is important to the transposition-type design of stator windings in large generators. The circuit network model of the stator transposition bar, including only resistance and reactance parameters, is proposed in this paper, and the calculation method for parameters is given. The analytical algorithm of circulating current in stator transposition bars is proposed based on the circuit network model. Contrary to the existing calculation method for circulating current, the presented analytical algorithm is a general and fast method for different transposition types, which can avoid establishing complex 3-D models. In order to validate the proposed analytical algorithm, the strand current and circulating current of less than 540° with a void transposition bar in a water-cooled turbogenerator are calculated by analytical algorithm and 3-D finite-element method.