Research On Loss And Inductance Of Permanent Magnet Synchronous Traction Motor For Rail Transit

Permanent magnet synchronous motor (PMSM) has advantages of highefficiency,high power density,easy to realize low speed, large torque, high speed andconstant power, and can meet the requirements of traction system for railwayvehicles,become a new direction of development in the field of locomotive tractionmotor. Loss and inductance are the important basis of performance analysis andoptimal design for permanent magnet synchronous traction motor. Aiming at thecalculation and study on the loss and inductance parameter of PMSM for rail transit,this paper mainly completed works of following aspects:Firstly, the losses of two principle prototype whose power is7.5kW and20kWare calculated, the calculation model for iron loss of rail transit traction motor is givenout, loss is calculated and analyzed in detail on considering of unevenly distributionof motor’s internal magnetic field and existing of harmonic magnetic fields, comparedwith the experimental value, loss correction factor is given, ensure the error in thereasonable range, and the proportion of efficiency and high efficiency field ofprinciple prototype is further checked. Meanwhile, the availability of calculationresults is verified through the loss test of two prototypes.Then, adopting the calculation method only need to solve the winding inductanceof one unit motor in one position, the inductance parameter of two principleprototypes is calculated and analyzed, the inductance parameters curve with changesin motor parameters is given. Measuring the inductance parameter byvoltmeter-ammeter method, the testing results are contrasted with computation whichindicated that the calculation error can satisfy the project requirements.Finally,the design of PMSM for rail transit is studied and carried out. Takingtheprototype of20kW as an example, the inner and outer diameter of stator and the corelength are confirmed. The design range of no-load EMF is given considering thematching of motor and controller.Through the calculation of loss, the pole-slot matchof the motor is chosen to achieve the purpose of high efficiency. Through the inductance parameter analysis of different rotor structure, determine the rotormagnetic circuit structure. The dimension of lightening hole is provided by thecomparison of motor’s performance. At last, the design scheme of20kW prototype isgiven.