A Calculation Method for the On-Load Cogging Torque of Permanent Magnet Synchronous Machine

This paper presents a new method to calculate the cogging torque of the permanent magnet synchronous machine under load condition. Combined with the mathematical expression of the cogging torque, it is found that the cogging torque will be influenced by the load. In order to accurately analyze the torque ripple of the motor at low speed and high torque operation and make it possible to reduce the cogging torque under load condition, it is necessary to calculate the cogging torque accurately. A calculation method for the on-load cogging torque of the PMSM, which the cross magnetization and core saturation have been taken into consideration, is proposed in this paper. The finite element analysis (FEA) and field-oriented control (FOC) contribute to the method, which mainly consists of three parts: elimination of the reluctance torque, calculation of the average torque, and the ripple torque and the separation of the cogging torque. By using this method, the cogging torques of a 16-pole/24-slot PMSM under different load conditions has been calculated. The result shows a very good agreement between simulation and experiment, which verifies the feasibility and effectiveness of the proposed method.

[1]  W. Q. Chu,et al.  On-Load Cogging Torque Calculation in Permanent Magnet Machines , 2013, IEEE Transactions on Magnetics.

[2]  D. Staton,et al.  Comparison of Analytical Models of Cogging Torque in Surface-Mounted PM Machines , 2012, IEEE Transactions on Industrial Electronics.

[3]  Z. Zhu,et al.  Average Torque Separation in Permanent Magnet Synchronous Machines Using Frozen Permeability , 2013, IEEE Transactions on Magnetics.

[4]  Z. Q. Zhu,et al.  Reduction of On-Load Torque Ripples in Permanent Magnet Synchronous Machines by Improved Skewing , 2013, IEEE Transactions on Magnetics.

[5]  D. Wu,et al.  Design trade-off between cogging torque and torque ripple in fractional slot surface-mounted permanent magnet machines , 2015, 2015 IEEE Magnetics Conference (INTERMAG).

[6]  Z. Zhu,et al.  Investigation of Torque Ripples in Permanent Magnet Synchronous Machines With Skewing , 2013, IEEE Transactions on Magnetics.

[7]  Libing Zhou,et al.  Reduction of Cogging Torque and Torque Ripple in Interior PM Machines With Asymmetrical V-Type Rotor Design , 2016, IEEE Transactions on Magnetics.

[8]  B. Mecrow,et al.  A Seminumerical Finite-Element Postprocessing Torque Ripple Analysis Technique for Synchronous Electric Machines Utilizing the Air-Gap Maxwell Stress Tensor , 2014, IEEE Transactions on Magnetics.

[9]  Changliang Xia,et al.  Cogging Torque Modeling and Analyzing for Surface-Mounted Permanent Magnet Machines With Auxiliary Slots , 2013, IEEE Transactions on Magnetics.

[10]  Katsumi Yamazaki,et al.  Torque Analysis of Interior Permanent-Magnet Synchronous Motors by Considering Cross-Magnetization: Variation in Torque Components With Permanent-Magnet Configurations , 2014, IEEE Transactions on Industrial Electronics.

[11]  Z. Q. Zhu,et al.  Optimal Step-Skew Methods for Cogging Torque Reduction Accounting for Three-Dimensional Effect of Interior Permanent Magnet Machines , 2017, IEEE Transactions on Energy Conversion.

[12]  Shigeo Morimoto Senior Member.  Trend of permanent magnet synchronous machines , 2007 .

[13]  Di Wu,et al.  Reduction of On-Load Terminal Voltage Distortion in Fractional Slot Interior Permanent Magnet Machines , 2016, IEEE Transactions on Energy Conversion.

[14]  Wenliang Zhao,et al.  The Method for Reducing Intrinsic Shaft Voltage by Suitable Selection of Pole-Arc Coefficient in Fractional-Slot Permanent-Magnet Synchronous Machines , 2018, IEEE Transactions on Magnetics.

[15]  Ki-Chan Kim,et al.  Analysis on Correlation Between Cogging Torque and Torque Ripple by Considering Magnetic Saturation , 2013, IEEE Transactions on Magnetics.

[16]  K. Abbaszadeh,et al.  On-Load Field Component Separation in Surface-Mounted Permanent-Magnet Motors Using an Improved Conformal Mapping Method , 2016, IEEE Transactions on Magnetics.

[17]  Narayan C. Kar,et al.  A Novel Current Injection-Based Online Parameter Estimation Method for PMSMs Considering Magnetic Saturation , 2016, IEEE Transactions on Magnetics.

[18]  Zhai Guofu,et al.  Permanent-Magnet Equivalent Model of Calculating Relay's Static Attractive Torque Characteristics by Finite Element Method , 2012, IEEE Transactions on Magnetics.

[19]  Sang-Yong Jung,et al.  Reducing Cogging Torque in Surface-Mounted Permanent-Magnet Motors by Nonuniformly Distributed Teeth Method , 2011, IEEE Transactions on Magnetics.

[20]  Ki-Chan Kim,et al.  A Novel Method for Minimization of Cogging Torque and Torque Ripple for Interior Permanent Magnet Synchronous Motor , 2014, IEEE Transactions on Magnetics.

[21]  Z. Zhu,et al.  Influence of Electric Loading and Magnetic Saturation on Cogging Torque, Back-EMF and Torque Ripple of PM Machines , 2012, IEEE Transactions on Magnetics.

[22]  Z. Q. Zhu,et al.  Cogging Torque Mitigation of Modular Permanent Magnet Machines , 2016, IEEE Transactions on Magnetics.

[23]  Damir Zarko,et al.  On-Load Analysis of Saturated Surface Permanent Magnet Machines Using Conformal Mapping and Magnetic Equivalent Circuits , 2018, IEEE Transactions on Energy Conversion.

[24]  Sang-Yong Jung,et al.  Design of IPMSM Applying V-Shape Skew Considering Axial Force Distribution and Performance Characteristics According to the Rotating Direction , 2016, IEEE Transactions on Applied Superconductivity.

[25]  Liu Shi-yong.  Optimization for the Asymmetric Angles of Magnetic Pole to Reduce Cogging Torque in Inner-buried PM Brushless DC Motors , 2008 .

[26]  Jang-Young Choi,et al.  Characteristic Analysis of Interior Permanent-Magnet Synchronous Machine With Fractional-Slot Concentrated Winding Considering Nonlinear Magnetic Saturation , 2016, IEEE Transactions on Applied Superconductivity.

[27]  N. Takorabet,et al.  Effect of magnet segmentation on the cogging torque in surface-mounted permanent-magnet motors , 2006, IEEE Transactions on Magnetics.

[28]  Jianguo Zhu,et al.  Core Loss Modeling for Permanent-Magnet Motor Based on Flux Variation Locus and Finite-Element Method , 2012, IEEE Transactions on Magnetics.

[29]  Ningning Chen,et al.  An Optimal Design Method for the Minimization of Cogging Torques of a Permanent Magnet Motor Using FEM and Genetic Algorithm , 2010, IEEE Transactions on Applied Superconductivity.

[30]  Kaiyuan Lu,et al.  Cogging Torque Reduction by Slot-Opening Shift for Permanent Magnet Machines , 2013, IEEE Transactions on Magnetics.

[31]  Shi Ka.  Cogging Torque Analysis for Permanent Magnetic Motors Using Maxwell Tensor , 2010 .

[32]  Z. Q. Zhu,et al.  Design Tradeoff Between Cogging Torque and Torque Ripple in Fractional Slot Surface-Mounted Permanent Magnet Machines , 2015, IEEE Transactions on Magnetics.

[33]  Yubo Yang,et al.  Study of cogging torque in surface-mounted permanent magnet motors with energy method , 2003 .

[34]  Juha Pyrhonen,et al.  Unequal Teeth Widths for Torque Ripple Reduction in Permanent Magnet Synchronous Machines With Fractional-Slot Non-Overlapping Windings , 2015, IEEE Transactions on Magnetics.

[35]  Z. Q. Zhu,et al.  On-Load Voltage Distortion in Fractional Slot Surface-Mounted Permanent Magnet Machines Considering Local Magnetic Saturation , 2015, IEEE Transactions on Magnetics.

[36]  Z.Q. Zhu,et al.  Analytical Methods for Minimizing Cogging Torque in Permanent-Magnet Machines , 2009, IEEE Transactions on Magnetics.