两电平空间矢量脉宽调制的简化算法和电压谐波分析方法.docx

文章编号：1000-3673（2014）09-2504-07中图分类号：TM 721文献标志码：A学科代码：47 文章编号：1000-3673（2014）09-2504-07 中图分类号：TM 721 文献标志码：A 学科代码：470·4051 两电平空间矢量脉宽调制的简化算法和 电压谐波分析方法 于心宇，魏应冬，姜齐荣 （清华大学 电机系，北京市 海淀区 100084） A Simplified Algorithm and A Method of Voltage Harmonic Analysis for Two-Level Space Vector Pulse Width Modulation YU Xinyu, WEI Yingdong, JIANG Qirong (Department of Electrical Engineering, Tsinghua University, Haidian District, Beijing 100084, China) ABSTRACT: The traditional algorithm for 2-level space vector pulse width modulation (SVPWM) is complicated with large computation. In this paper, based on the volt-second balance equation of traditional algorithm, the linear equations of the pulse time of switching devices in 3-phase upper arms are set up and solved, thus a simplified algorithm for 2-level SVPWM without coordinate transformation and sector judgment is proposed, which reduces a lot of computation and is much easier to implement. Based on the simplified algorithm, a method of voltage harmonic analysis for synchronous SVPWM is proposed, which presents the generic expressions of the voltage harmonic spectrum when the distribution of zero vectors is varied, and explains the distribution characteristics of voltage harmonics qualitatively. The accuracy of the simplified algorithm and the novel method of voltage harmonic analysis for 2-level SVPWM are verified by the simulation results based on PSCAD/EMTDC. 证了所提的两电平 SVPWM 简化算法和电压谐波分析方法 的准确性。 关键词：两电平变流器；空间矢量脉宽调制；简化算法；电 压谐波分析 DOI：10.13335/j.1000-3673.pst.2014.09.030 0 引言 空间矢量脉宽调制(space vector pulse width modulation，SPWM)具有直流电压利用率高、易于 数字化实现等优点[1]，因而在电机控制[2-3]、电能质 量治理[4-5]、静止同步补偿[6]等领域得到了广泛的研 究和应用。 传统的两电平 SVPWM 算法包括坐标变换、扇 区判断、矢量作用时间计算等多个步骤，流程复杂， 运算量较大，因此许多文献着重研究了 SVPWM 的 数学本质和简化算法。文献[7]指出 SVPWM 与在调 制波中加入零序分量并进行规则采样的正弦脉宽 调制(sine pulse width modulation，SPWM)等效。文 献[8-9]通过简化扇区判断条件，减少了 SVPWM 的 部分三角函数运算。文献[10]提出一种两相 120° 坐标系下的 SVPWM 算法，该算法不需要进行扇区 判断，但需要进行 2 次坐标变换运算，无理数和三 角函数的运算量仍较大。文献[11-12]分别提出了 2 种不通过坐标变换直接计算开关器件脉宽