Mechanism of Torque Ripple Generation by Time and Space Harmonic Magnetic Fields in Permanent Magnet Synchronous Motors

In this article, we investigate mechanism of torque ripple generation by time and space harmonic magnetic fields in permanent magnet synchronous motors to obtain advanced motor designs. The general expression between the torque ripples and harmonic air-gap flux densities in the motor is derived by using Maxwell stress tensor. <a>Both the numerical and experimental verifications of this expression are carried out.</a> Then, the major harmonic magnetic fields that produce the torque ripples are specified and the differences between the surface and interior permanent magnet synchronous motors are investigated. According to these investigations, the shape of the rotor surface of an interior permanent magnet motor is optimized. It is clarified that specific harmonic components of the torque ripples in interior permanent magnet synchronous motors can be reduced to be nearly zero by optimizing the rotor surface shape.

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Mechanism of Torque Ripple Generation by Time and Space Harmonic Magnetic Fields in Permanent Magnet Synchronous Motors

10.36227/techrxiv.14569485 ◽

2021 ◽

Author(s):

Katsumi Yamazaki ◽

Kento Utsunomiya ◽

Hiroaki Ohiwa

Keyword(s):

Magnetic Fields ◽

Permanent Magnet ◽

Torque Ripple ◽

Time And Space ◽

Permanent Magnet Synchronous Motors ◽

Space Harmonic ◽

Synchronous Motors ◽

Interior Permanent Magnet ◽

Rotor Surface ◽

Torque Ripples

In this article, we investigate mechanism of torque ripple generation by time and space harmonic magnetic fields in permanent magnet synchronous motors to obtain advanced motor designs. The general expression between the torque ripples and harmonic air-gap flux densities in the motor is derived by using Maxwell stress tensor. <a>Both the numerical and experimental verifications of this expression are carried out.</a> Then, the major harmonic magnetic fields that produce the torque ripples are specified and the differences between the surface and interior permanent magnet synchronous motors are investigated. According to these investigations, the shape of the rotor surface of an interior permanent magnet motor is optimized. It is clarified that specific harmonic components of the torque ripples in interior permanent magnet synchronous motors can be reduced to be nearly zero by optimizing the rotor surface shape.

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Extended Permanent Magnet Synchronous Motors Speed Range Based on the Active and Reactive Power Control of Inverters

Energies ◽

10.3390/en14123549 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3549

Author(s):

Pham Quoc Khanh ◽

Viet-Anh Truong ◽

Ho Pham Huy Anh

Keyword(s):

Power Control ◽

Permanent Magnet ◽

Reactive Power ◽

Control Method ◽

Speed Control ◽

Torque Ripple ◽

Current Control ◽

Permanent Magnet Synchronous Motors ◽

Synchronous Motors ◽

Speed Range

The paper proposes a new speed control method to improve control quality and expand the Permanent Magnet Synchronous Motors speed range. The Permanent Magnet Synchronous Motors (PMSM) speed range enlarging is based on the newly proposed power control principle between two voltage sources instead of winding current control as the conventional Field Oriented Control method. The power management between the inverter and PMSM motor allows the Flux-Weakening obstacle to be overcome entirely, leading to a significant extension of the motor speed to a constant power range. Based on motor power control, a new control method is proposed and allows for efficiently reducing current and torque ripple caused by the imbalance between the power supply of the inverter and the power required through the desired stator current. The proposed method permits for not only an enhanced PMSM speed range, but also a robust stability in PMSM speed control. The simulation results have demonstrated the efficiency and stability of the proposed control method.

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Direct Torque Control for Permanent Magnet Synchronous Motors Based on Fuzzy Regulator

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.998-999.607 ◽

2014 ◽

Vol 998-999 ◽

pp. 607-612

Author(s):

Xiang Tang ◽

Jun Gu ◽

Ting Gao Qin

Keyword(s):

Permanent Magnet ◽

Permanent Magnet Synchronous Motor ◽

Direct Torque Control ◽

Torque Ripple ◽

Torque Control ◽

Permanent Magnet Synchronous Motors ◽

Synchronous Motors ◽

Pi Regulator ◽

Harmonic Content ◽

Fuzzy Regulator

In this paper, a method of direct torque control (DTC) for permanent magnet synchronous motor (PMSM) based on fuzzy regulator is proposed. It overcomes the disadvantages such as speed drop with load, torque ripple etc., which happens in the DTC for PMSM based on conventional PI regulator. The simulation results show that, the DTC for PMSM based on fuzzy regulator can effectively improve the system loading capability and significantly reduce the torque ripple and the harmonic content of the system. Therefore, it can comprehensively improve the system performance.

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