| Permanent magnet synchronous machine(PMSM)possesses the advantages of high power density,simple construction,high power factor,and good control characteristic.It has been widely applied in mechanical processing industry,electric tools,flywheel energy storage,high speed centrifuge and high speed compressor etc.However,problems of losses,temperature rise and heat dissipation brought by the high speed,high frequency and high power density are becoming more and more serious.Therefore,computing the temperature distribution of the PMSM is essential.Thermal network method,the finite element method(FEM),and the computational fluid dynamics(CFD)method are frequently used in computing the temperature field of the machine.In this paper,the heat transfer theories and the computational fluid dynamics knowledge are described first.Then a thermal model of the PMSM's components is built.At the meantime,the model of the coolant air flow in the PMSM is modeled.The three dimensional lumped parameter thermal network is constructed by combining the model of thermal model of the machine components and the coolant air flow together.Equations describing the machine components and the coolant air flow can be handled in on equation group at the same time.This model takes the influence brought by the temperature difference in the axial direction to the temperature distribution into account.A fluid-thermal coupling field simulation is proposed to certify the validation of the three dimensional LPTN model.A bi-directional coupled field simulation's computational amount is big and is time wasting which is highly demanding for the hardware.This paper proposes a simplified fluid-thermal coupling field simulation.This method achieves a fast convergence speed while keeps a relative high precision.At last,the results of the three dimensional LPTN and the coupling field simulation are compared with the validation of the LPTN model.This model can be applied in the axial ventilation PMSM's optimization design procedure. |
PDF Full Text Request