| High-power high voltage line-start permanent magnet synchronous motor withmany advantages of high efficiency and high power factor, high starting torque,low starting current, operation and convenient maintenance. It can be applied tothe defense, steel, metallurgy, electric vehicles, ships to promote industry.Research of this motor demonstrate the prospects for the development of energy-efficient motors. If the rotor does not have the air duct, the temperature of statorand rotor may correspondingly higher. The excessive rotor temperature makesthe decline in the performance of permanent magnet. It will not only affect theperformance and service life of the motor running, even will result in permanentmagnet demagnetization so that the motor does not work. Therefore it is veryimportant to calculate high-voltage line-start permanent magnet synchronousmotor fluid and temperature fields.In this paper, line-start permanent magnet synchronous motor for high-powerhigh-voltage fluid heat transfer coupling field in the case of presence orabsence of rotor ventilation structure. To all air315kW6kV,6pole solid rotorpermanent magnet synchronous motor, for example.Three-dimensional globalfluid and solid coupling heat transfer mathematical model is established. Lossbased on the two-dimensional transient electromagnetic field, solving the motorcooler fluid-solid coupling field by loop iteration based on the finite volumemethod, the motor rated conditions fluid flow rate and the temperature of theglobal distribution is established. Air flow rate variation along the flow directionof the stator axis radial ventilation trench is obtained. Air speed distribution inthe different radial positions within the air gap along the axial direction isanalyzed. The temperature variation of the rotor and the cage bar in the axial direction is studied. The temperature of the permanent magnets actual value iscompared, the method used is verify accuracy and validity.Due to higher rotor temperature rise when rotor does not have ventilationstructure, increase rotor axial and radial ventilation structure in the solid. Airvolume distribution of the rotor has or has not axis radial ventilation structure iscompared. Air speed and temperature in the ventilation structure along the radialdirection changes law when rotor has or has not axis radial stator radialventilation is obtained. The cooling effect of the rotor ventilation structure to thestator winding and rotor temperature rise is studied, found that the rotor axisradial ventilation structure can effectively reduce the temperature rise of rotor.Finally, in order to study the effect of cooling fan size to motor fluid andtemperature fields, fluid heat transfer coupling field under different inlet coolingair flow is calculated. The effect of cooling air amount to flowing state of thefluid in stator ventilation trench is analyzed. The variation of the stator windingtemperature with cooling air amount is obtained, permanent magnet temperatureof rotor without shaft radial ventilation structure up by the impact of the coolingair flow size is compared. And get some useful conclusions for ventilationstructure and cooling fan further optimized. |
