Cao Junci

Thermal analysis of solid rotor in PMSM used for EV

A solid rotor permanent magnet synchronous motor (PMSM) is developed for the electric propulsion part in electric vehicles (EV). The rotor in this kind of motor is composed of splits solid bodies, interior permanent magnets and starting bars. Wedges and bars are shot circuited by end rings that promote the generation of starting torque jointly. While PMSM used in EV, it may need to start frequently at different load, which would cause eddy losses in rotor and related to thermal demagnetization of permanent magnet directly. In this paper, a prototype of 30kW solid rotor PMSM is proposed, and numerical calculation models for thermal analysis are established. The 2D electromagnetic fields were calculated by using finite element method (FEM) first and motor losses in rotor were determined. From the analysis of fluid analysis of air in airgap, an effective coefficient of heat transfer is proposed to deal with the complex heat exchanges between rotor and stator. Then steady thermal field is analyzed, and influences of motor fan, loads and stray loss on rotor temperature distribution were studied. Some associate test work has been done with results in a good agreement with the analysis data. Some reasonable conclusions were obtained, which can provide some help for the design of this kind of PMSM and its application in EV.

Analysis of the influence of rotor material on IMCCR temperature field

A new kind of induction motor with compound cage rotor(IMCCR) is developed in this paper, in which rotor bar is composed of upper part made of alloy material (conductor of electric and magnetic) and lower part made of cast aluminum. Firstly, the calculating models of the machinepsilas electromagnetic field and whole region(include stator and rotor) temperature field were established and some losses were obtained through analyzing electromagnetic field of IMCCR by using finite element method(FEM), which taken as the heat souse of temperature fields. Thus the unidirectional electro-thermal weak coupling analysis was achieved. Then, by changing the heat conductivities of the rotor alloy cage, its influence on motor temperature distribution was analyzed, and some references for rotor material study could be obtained.

Calculation and Analysis of Starting Performance of Low Power Induction Motor with Compound Cage Rotor

A low power induction motor with compound cage rotor is illustrated in this paper. Permeability and conducting material is inset in the bar, which forms novel induction motor with compound cage rotor. Considering the feasibility of technology, two kinds of rotor slot shape are designed. Then the starting and operating performance of the motor is calculated by 2D finite element model of electromagnetic field[1]. Meanwhile, the height of compound material in the bar is changed to analysing the influence of starting and operating performance by it. The conclusion prove that the novel induction motor with compound cage rotor has batter starting performance than the common induction motor with the same seat No.

The heat conducting analysis of transient temperature field in IMCCR with discontinuous blocked rotor under different structure

A new kind of induction motor with compound cage rotor(IMCCR) is developed in this paper, in which rotor bar is composed of upper part made of alloy material (conductor of electric and magnetic) and lower part made of cast aluminum. The transient heat conducting process of IMCCR running with discontinuous blocked rotor was studied, in which two different structure rotors were compared analyzed. The transient temperature field was numerically calculated by using the method of coupling electromagnetic field and temperature field, in which the continuous process with application of full voltage during 10s rotor locked, natural cooling during 600s disconnection of motor and during repeated next 10s rotor blocked is simulated. Based on the above, this paper presented the heat conducting process of the stator equivalent windings and change trend of bidirectional heat conducting of parts of stator. Then radial transient heat conducting processes of rotor when blocked and natural cooling were analyzed. At last, the influence of different material conductivity on the temperature distribution near the inner circle of stator was explored, in which the calculated values at the measured points were compared with the tested ones.

Material Characteristic Analysis and Different Load Performances Calculation of IMCCR

A new type of induction motor with compound cage rotor (IMCCR), its bars composed of cast-aluminum and alloy is proposed. The kinetic equations and state equations of the motor are established, and the starting process of the induction motor is simulated and analyzed. Meanwhile the method employed to solve the two dimensional (2D) sinusoidal time-varying field is given. Taking the stator terminal voltage and the power equation as the constraint conditions, by iterating the stator currents and rotor slip respectively, the performances of the motor can be obtained. The starting process of the motor is simulated by state equations, and the operating performance is obtained by using finite element method. The performances are calculated for different rotor slot shapes and different alloys respectively. The better performances of the IMCCR are verified by comparing the induction motor with compound cage bar with ordinary induction motors.

Design and Analysis of IMCCR Used in Electric Vehicle

There are some deficiencies in operation performance of the ordinary motors, as well as the staring performance of solid rotor motors. For the using of electric vehicle, a new type of induction motor with compound cage rotor (IMCCR) is proposed in this paper. To analyze its performance, the physical model and FEM method for the 2D sinusoidal time-varying electromagnetic field are given firstly. Taking the stator terminal voltage and power equation as the constraint conditions, the stator current and slip of this motor are calculated, thus motors performances can be obtained. The performances are calculated for different rotor slot shapes and different alloys respectively. The better performances of the IMCCR are verified by comparing the induction motor with compound cage bar with ordinary induction motors

Simulation of Starting process and Calculation of operating Performances of Induction Motor with Compound Cage Rotor

A new type of induction motor with compound cage bar composed of cast-aluminum and alloy is proposed. The motor state equations are established and the method employed to solve the two dimensional (2D) sinusoidal time-varying field is given. The starting process of the motor is simulated by state equations, and the operating performance is obtained by using finite element method. The performances are calculated for different rotor slot shapes and different alloys respectively. The better performances of the induction machine with compound cage rotor are verified by comparing the induction motor with compound cage bar with ordinary induction motors