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The electromagnetic radiation emission model of motor drive System for electric vehicles (EVs) is presented in this paper. First, the radiation electromagnetic interference (EMI) mechanism of the motor drive system is analyzed and investigated by experiment. The radiation EMI mainly comes from the common mode current flowing along the three phase cable between the inverter and the motor. Secondly, the feasibility of the finite element method (FEM) is verified by calculating the wire electromagnetic field around and the radiation EMI model of the motor drive system is established using the FEM. The simulation and experimental results show that the proposed model is feasible.

Modern distance education is an important form of adult higher education, and has become an important part of higher education in china. Off campus learning center is a support institution for the study of Modern Distance Education in Colleges and universities. Comprehensive evaluation of off-campus learning centers is an important means of strengthening the management of off-campus learning centers. The students’achievement as one of the comprehensive evaluation indicators of the off-campus learning center can better reflect the comprehensive ability of the management and service of the off-campus learning center. This paper applies the students’achievements in the learning process and the TOPSIS method and the grey correlation to the comprehensive analysis and ranking of the off-campus learning center, so as to provide the feasible method and theoretical basis for the students' academic achievement as the evaluation index of the off-campus learning center.

In this paper, a method for conducted electromagnetic interference (EMI) prediction in Electric Vehicle motor drive system based on components’ circuit models is presented. Firstly, the characteristics of the components are analyzed and the equivalent circuits are drew; then, the parasitic parameters of the electromagnetic device are extracted by the measurement, analytical solution and finite element method (FEM); and finally, the circuit model of the whole motor drive system in high frequency range is established. This model is verified by the measurement and simulation results in the frequency domain.

The common-mode current along the harness is one of the main reasons which can not meet the automotive electromagnetic compatibility (EMC) standards for equipment or system. So, the harness model is the critical factors for the automotive EMC prediction. In this paper, the harness network equivalent model is proposed, which is based on the terminal loads and the equivalent wave impedance. The equivalent model is also demonstrated from the simulation results by finite element method.

In this paper, common mode (CM) conducted perturbations are predicted and compared with experiments in a full-bridge transformer-isolated buck converter system, thanks to a complex approach based on experimental measurements and on the modeling of the complete equivalent circuit. Its different part are considered and represented by a circuit of lumped parameters. Simulation and experiment of CM emission in the conducted frequency range (150 kHz-30 MHz) are compared. It is shown that the CM emission in the system can be calculated by the proposed model, and experiment has successfully confirmed this approach.

The application of the high-voltage supply system and the motor drive system in electric and hybrid-electric vehicles can leads to a significant increase in electromagnetic compatibility. The influence of traction batteries as part of the electromagnetic interference path must be considered. In this paper models of single cell, cells connected in series and cells connected in parallel are developed based on the measured impedance curve of single cell, the models are formulized in the frequency domain and verified by impedance measurement on Ni-MH batteries, the results allow the simulation of batteries as interference path and the prediction of external electric fields and magnetic fields.

In this paper, we consider the following nonlinear equation $$ u_t + 2ku_x - u_{xxt} + au^2 u_x = 2u_x u_{xx} + uu_{xxx} , $$ which is a modified form of the Camassa-Holm equation. We construct four new explicit periodic wave solutions by bifurcation method of dynamical systems. We also obtain two explicit solitary wave solutions via the limits of the explicit periodic wave solutions. One of the two solitary wave solutions is new.