Investigation of End Leakage Reactance and Its Influence on the Accuracy in Performance Calculation of Large Double Canned Induction Motors

The end leakage reactance of large double canned induction motors is important for the performance calculation by two-dimensional (2-D) numerical analysis, which calculation accuracy directly affects the calculation results of performances. However, there are many special metallic structures in the end region of large double canned induction motors. Due to these structures, the distribution complicacy of end magnetic fields and the calculation difficulty of the end leakage reactance are increased. To solve this problem, a 5-MW double canned induction motor is taken as the research object; 3-D finite element calculation model of its end region is established and solved. The end magnetic field and end leakage reactance are obtained. The influence of these special structures on the end magnetic field and end leakage reactance are analyzed in detail. Performances of large double canned induction motors are calculated by the 2-D numerical analysis with different end leakage reactance coupling. The calculation results of the end leakage reactance are indirectly verified through the stator current and power factor as the accuracy of the end leakage reactance directly affects calculation results of the stator current and power factor.