Wang Baochao

Periodic Carrier Frequency Modulation in Reducing Low-Frequency Electromagnetic Interference of Permanent Magnet Synchronous Motor Drive System

This paper introduces the periodic carrier frequency modulation (PCFM) for permanent magnet synchronous motor (PMSM) drive systems so as to reduce the low-frequency electromagnetic interference (EMI). PMSMs are widely used in many applications and they are usually fed by pulsewidth modulation (PWM) inverters. The EMI of PMSM, which results from the switch of power device, generates undesirable effects on the control system. Therefore, it is of importance to reduce the EMI of PMSM. The common mode (CM) conducted EMI model of the PMSM drive system is constructed to investigate the CM voltage. The simulations and experiments of PMSM fed by the fixed frequency PWM (FFPWM) and PCFM are implemented to analyze the CM conducted EMI. The CM EMI spectra of PMSM fed by the FFPWM and PCFM with different spreading frequency widths are compared to explore the influence of PCFM on the CM conducted EMI. The regular patterns on PCFM in reducing the CM conducted EMI of PMSM drive systems are revealed.

Electromagnetic design of a novel hybrid flux SMCs PMSM

The hybrid flux PMSM includes both axial flux and radial flux, so its design method is different from the traditional cylindrical permanent magnet synchronous motor. In this paper, based on the analysis of the structure and operation principle of the hybrid flux motor, the design principle of the motor is given. The authors study the effects of slotting, permanent magnet thickness, and pole-slot match on the motor and determine the important parameters of the motor. Finally, the finite element method is used to verify the electromagnetic performance of the motor, and the correctness of the proposed design principle is verified.

Characteristics of soft magnetic composites and application in new structure motor

Soft magnetic composites (SMCs) is a new kind of powder metal material. Compared with the traditional silicon steel material, it has the advantages of low eddy current loss, isotropic magnetic conductivity and thermal conductivity, easy to make parts with complex structure, and is suitable for motor core materials, especially in high-frequency working conditions. This paper introduces the characteristics of SMCs, and classifies the application of the material in the motor, and finally discusses the shortcomings and the development directions.

Analysis and Design of SPM Machines With Fractional Slot Concentrated Windings for a Given Constant Power Region

This paper presents a novel analysis and a design method of surface-mounted permanent magnet (SPM) machines with fractional slot concentrated windings (FSCWs) for a given constant power region ratio. The characteristics of working points in the constant power region are analyzed, and a method of quantifying important parameters, magnet flux, and synchronous inductance is proposed. According to the analysis, the design method of SPM machines with the FSCWs and notes is provided. Based on the proposed method, a double-layer 20-pole/24-slot SPM machine is taken as an example and designed. The designed machine is analyzed by the finite element method (FEM), and the constant power experiment is carried out on the prototype manufactured as design. The results validate the analysis and the design method in this paper.