Thermal Analysis and Improved Thermal Modelling of a 200 kW Traction Induction Motor in Urban Electric Train Application

One important usage of electric motors is railway transportation. There are different types of motor analyses available in railway transportation such as electromagnetic, thermal and mechanical analyses. The goals of thermal analysis are to calculate and monitor motor temperature in components, avoid motor damage, insulation break and increase lifetime. Methods of thermal analysis include: lumped parameters (LP), finite element (FEA) and computational fluid dynamics (CFD). Good analysis should be suitable for the motor type and geometry, obtain good accuracy and reduce time consumption. In this paper, the authors perform the thermal analysis of a self-ventilated 200 kW induction traction motor used in urban trains. First, the thermal network is created and the proposed LP approach is provided to calculate temperatures. This model consists of two steps which makes calculation easier, takes less time and can be used for complex parts without changing the whole model. The temperatures of important parts such as end winding can be calculated by the proposed model with simple equations, without any change in motor parameters matrix, so the proposed model is more flexible and can be used for different cases. Then, FEA and CFD are used to simulate the motor. Some model parameters are optimised using equations to make the model more accurate. Finally, simulation results are compared with experimental test results in order to validate motor performance and the proposed model results.