Research On Coupled Fluid-solid Heat Transfer Of Switched Reluctance Motor For Crane Considering Rotational Condition

With the rapid development and continuous progress of the industrial field,crane motors play an indispensable role in industrial production and material handling.Traditional crane motors use three-phase induction motors,which have disadvantages such as small starting torque and low efficiency at low speeds.Three-phase induction motors cannot meet the needs of the modern crane industry.Switched reluctance motors have the advantages of wide speed range,large starting torque and excellent dynamic response.It can be applied to the occasions of frequent start and stop,and various load operating conditions.The electromagnetic field,fluid flow and temperature distribution of switched reluctance motors for cranes have been deeply studied in this paper.The main contents are as follows:First of all,a 5.5k W switched reluctance motor for cranes is taken as the research object in the article.A two-dimensional transient electromagnetic field-control circuit coupling calculation model is established.Based on the time-stepping finite element method of field-circuit coupling,the flux density of the stator and rotor under rated conditions is studied.The core loss of the stator and rotor core under different load conditions is calculated and analyzed.The measured value of the three-phase current under rated load operation and the calculation result are compared,and the feasibility of the transient electromagnetic field-control circuit coupling calculation model of the switched reluctance motor for crane is verified.Secondly,the three-dimensional fluid and heat transfer coupling calculation model of the switched reluctance motor used in cranes is established considering the rotation of the rotor and the external centrifugal fan.The finite volume method is used to study the complex fluid flow inside and outside the switched reluctance motor.The fluid velocity in the air gap between the stator and rotor and the fluid velocity around the centrifugal fan of the switched reluctance motor operating at rated speed are studied separately,and the distribution law of fluid flow around the casing is analyzed and calculated.Comparing the measured and calculated values of the fluid flow velocity of the different cooling fin ducts of the chassis under rated speed operation,the accuracy of the calculated results of the fluid field of the switched reluctance motor is verified.Finally,the unidirectional magneto-thermal coupling calculation method is used to calculate and analyze the temperature distribution of each component in the switched reluctance motor for cranes under rated load.The variation law of insulation temperature of stator winding,stator core,rotor core and stator winding of switched reluctance motor under different load conditions is studied.The temperature of each component in the switched reluctance motor for cranes under the unidirectional coupling and the bidirectional magneto-thermal coupling calculation method is compared and analyzed,and the calculation results of the stator winding temperature under the two magneto-thermal coupling calculation methods are compared with the experimental test result,which verifies the feasibility of the calculation method and provides a reference for the development of switched reluctance motors for larger capacity cranes.