摘要
【目的】内置式永磁(interior permanent magnet,IPM)电机因具有结构稳定、效率和功率因数高等优点被广泛用作井下潜油电机,油井井筒直径的限制和高温工作环境要求潜油永磁电机具有较高的转矩密度和较强的永磁体抗退磁能力。本文提出一种由一字型磁极和弓形磁极合成的正弦磁极,充分利用一字型磁极上方的转子空间,增加永磁体用量和d轴永磁体厚度,达到提高IPM电机功率密度和抗退磁能力的目的。【方法】保持一字型磁极尺寸恒定,采用有限元法分别研究了弓形磁极矢高对IPM电机短路电流、抗退磁能力以及空载和负载电磁性能的影响,并分析了内在原因。此外,采用等效圆环法研究了磁极矢高对转子铁心最大应力影响,保证转子机械强度。【结果】随着正弦磁极矢高的增加,尽管IPM电机的短路电流会随之增加,但其永磁体展现出更强的抗退磁能力;增加矢高虽会增加转子铁心的最大应力,但其最大应力远小于铁心材料的屈服应力,机械强度能满足实际需求;矢高较小时对IPM电机磁阻转矩的影响可以忽略,当矢高大于3 mm后,其磁阻转矩最大值随矢高的增加而下降明显,但总输出转矩一直随着矢高的增加而增加,转矩波动则随之减小。【结论】综合考虑磁极矢高对电机性能影响,选择了合适的正弦磁极尺寸,制造了样机并进行试验;试验结果与二维有限元仿真结果吻合良好,验证了提出的正弦磁极结构能有效提高IPM电机的转矩密度和抗退磁能力,为内置式永磁电机转子磁极设计提供了新的思路。
[Objective]Interior permanent magnet(IPM)motors are widely adopted as submersible motors in oil well applications due to their structural stability,high efficiency,and superior power factor.However,the constrained wellbore diameter and elevated ambient temperatures in deep-well environments impose stringent requirements for enhanced torque density and anti-demagnetization capability of IPM motors.To address these challenges,a novel sine-shaped permanent magnet(PM),synthesized from flat and arched PM,was adopted in this study.The adopted PM optimizes rotor space utilization above conventional flat PM,thereby increasing permanent magnet volume and d-axis permanent magnet thickness,improving torque density and anti-demagnetization capability of IPM motors.[Methods]Maintaining constant dimensions of the flat PM,the finite element analysis(FEA)was employed to systematically evaluate the effects of arched PM sagitta on short-circuit current,anti-demagnetization capability,and no-load and on-load electromagnetic performance.Moreover,the equivalent ring method was implemented to quantify the maximum stress of the rotor core under various sagittas,ensuring the mechanical integrity of the optimized rotor structure.[Results]Although the short-circuit current of the IPM motor will increase as the sagitta increases,its permanent magnets exhibit stronger anti-demagnetization capability.While increasing the sagitta will increase the maximum stress of the rotor core,it is much lower than the yield stress of the core material,meeting practical needs sufficiently.Moreover,the effect of a smaller sagitta on the reluctance torque of the IPM motor can be ignored.When the sagitta is greater than 3 mm,the maximum reluctance torque decreases significantly as the sagitta increases,while the total output torque keeps increasing and torque ripple decreases.[Conclusion]Taking into account the overall influence of the sagitta on the motor′s performance,a suitable sine-shaped PM size was selected,and a prototype was manufactured and tested.The experimental results are in good agreement with the 2D FEA simulation results,verifying the accuracy of the simulation analysis,which provides a new approach for the rotor design of the IPM motors.
作者
甄东芳
孙大伟
刘明凯
王通
马增华
宋宏志
刘源
ZHEN Dongfang;SUN Dawei;LIU Mingkai;WANG Tong;MA Zenghua;SONG Hongzhi;LIU Yuan(Business Division of Production Optimization,China Oilfield Services Limited(COSL),Tianjin 300459,China;School of Electrical Engineering,Shenyang University of Technology,Shenyang 110870,Liaoning,China)
出处
《沈阳工业大学学报》
北大核心
2025年第5期584-593,共10页
Journal of Shenyang University of Technology
基金
国家自然科学基金项目(52177054)
中海油田服务股份有限公司项目(E-23247008)。
关键词
内置式永磁电机
潜油电机
正弦磁极
抗退磁能力
转矩密度
短路电流
转子应力
等效圆环法
interior permanent magnet motor
submersible motor
sine-shaped permanent magnet
anti-demagnetization capability
torque density
short-circuit current
stress of rotor
equivalent ring method
