六相永磁同步电机驱动系统直流环节电容器电流RMS值估计  

Estimation of Current RMS for DC Link Capacitor of S-PMSM Drive System

作　　者：张志刚 常加冕 张鹏程 ZHANG Zhigang;CHANG Jiamian;ZHANG Pengcheng(College of Electrical and Information Engineering,Hunan University of Technology,Zhuzhou,Hunan 412007,China;College of Electronic Information and Electrical Engineering,Changsha University,Changsha,Hunan 410000,China)

机构地区：[1]湖南工业大学电气与信息工程学院,湖南株洲412007 [2]长沙学院电子信息与电气工程学院,湖南长沙410000

出　　处：《控制与信息技术》2023年第5期62-66,共5页CONTROL AND INFORMATION TECHNOLOGY

基　　金：湖南省教育厅重点项目(22A0603)。

摘　　要：六相永磁同步电机(PMSM)驱动系统相比传统三相PMSM驱动系统具有低压大功率、转矩脉动小、控制灵活和容错率高等特点。直流环节电容器对驱动系统的稳定性起着决定性作用,但由于其结构特殊,需承受较高的纹波电流均方根(RMS)值。而直流电容器的电流RMS值是决定其使用成本、体积和寿命的重要参考指标。因此对直流电容器的电流RMS值进行估计显得尤为重要。针对采用传统双重傅里叶积分算法计算电容的电流RMS值时存在的过程繁琐、涉及许多未解积分等问题,文章提出了一种基于多项式插值求积法Cotes的直流电容器电流RMS值的计算方法。即在等距离步长中分布5个采样点,对推导出的函数积分生成近似解,采用Cotes法可以省去大量的积分计算过程,同时提高计算精度。该方法简化了传统算法的繁琐计算过程并且保证了较高的计算精度,可为直流环节电容器的优化选型和寿命监测控制器设计提供指导。最后,文章将所提方法与现有方法进行了对比分析,实验结果验证了所提方法的计算速度比传统双重傅里叶积分算法快50%左右,且计算精度较牛顿3/8法提高了约5%。The six-phase permanent magnet synchronous motor(PMSM)drive system has the characteristics of low voltage,high power,small torque ripple,flexible control,and high fault tolerance compared with traditional three-phase PMSM drive systems.The DC link capacitor plays a decisive role in the stability of the drive system.However,due to its unique structure,it needs to withstand a high root mean square(RMS)value of ripple current.The current RMS value of DC capacitors is an important reference indicator for determining their usage cost,volume,and lifespan.Therefore,it is particularly important to estimate the current RMS value of DC capacitors.Given the sophisticated processes involved and numerous unresolved integrals while calculating the current RMS value of the capacitor using traditional double Fourier integral algorithm,this paper proposes a method to calculate the current RMS value of the DC capacitor based on polynomial interpolation and quadrature method Cotes.This involves taking five sampling points distributed at equidistant interval,and integrating the derived function for an approximation solution.The Cotes method eliminates numerous integration calculations,thus improving calculation accuracy.The proposed technique simplifies the tedious calculation process of traditional algorithms and guarantees high calculation accuracy,providing guidance for optimizing the selection of DC link capacitors and the design of life monitoring controllers.Finally,a comparative analysis was conducted between the proposed method and existing methods.Experimental results verify that the proposed method improves calculation speed by about 50%over the traditional double Fourier integral method,and improves calculation accuracy by about 5%over the Newton 3/8 method.

关 键 词：六相永磁同步电机 直流电容 电流RMS值 双重傅里叶积分 

分 类 号：TM351[电气工程—电机] U262.3[机械工程—车辆工程]