Research Of Temperature Rise For High-voltage Induction Motor With Compact Type In Starting Process

High-voltage induction motor with compact type is a new product developedbased the medium-size high-voltage induction motors, with purpose of reducingthe size of the motor as well as increasing the power density. The center height ofhigh-voltage induction motor with compact type is reduced, under the samecapacity, by two levels on average when compared to ordinary high-voltageinduction motors, thus its power density can be improved. According togeometrical similarity law, the increasing of the power density will certainly leadto the problem of internal temperature rise. If the temperature is too high, failures,such as discharging and short circuit, would occur inside the motor, which wouldeven burn down the motor. An accurate analysis on both fluid and temperaturefields inside the motor is therefore required.Starting a motor is a dynamic process, during which the fluid motion andheating inside the motor are changing over time. In this article, we studied thechanges in temperature rise when staring the high-voltage induction motor byusing a field-circuit coupled method. We took the YJKK500-4,2500kW compactmotor as the case for our study. First, we made use of both the coordinatetransformation and vector transformation analyzes the dynamic state of the motorand to obtain the dynamic equation. Based on the dynamic equation theory, weinvestigated and computed the specific changes in of the motor under differentloads, and took the results as transient heat source for simulation. Next, weanalyzed the heat dissipation of the motor. In this study, we built a wind-resistance network to figure out the matching of the wind volume and thedistribution of the weed speed inside the motor, with intention to provideinformation of heat dissipation for simulation. Finally, we combined the finite element simulation with above analysis. The model was built on actual structureand size of the motor. The fluid field and temperature field were simulated byusing basic principles of fluid mechanics and thermodynamics to study thetemperature rise of the motor at different moments.The field-circuit coupled algorithm can simplify the complexity in loadingboundary conditions of motor’s heat source and fluid during a transient process,thus can improve the accuracy of computing the fluid field and temperature fieldduring starting the motor. Hence we have a more clear understanding on fluidmotion in ventilating ducts of the motor as well as on changes in temperature rise.In this way we can ensure the reasonableness of design and can guarantee, tosome extent, the safety of the motor.