Abstract

Frequency-controlled electric drives constructed according to the scheme “frequency converter–ac electric motor” are widely used in modern technology and electric drive systems of various vehicles. At the moment, many methods of modulating the voltage at the output of the frequency converter have been developed in order to bring its shape closer to the sinusoidal one with the lowest losses. Since, depending on the task at hand, different characteristics of voltage modulation are prioritized, it is necessary to know the advantages and disadvantages of the main algorithms for generating voltage at the output of the frequency converter. A feature of high-power electric drive systems is the impossibility of using high switching frequencies of the power switches of the frequency converter, which makes it necessary to know the laws of the formation of the voltage spectrum when using a particular method. The article considers the basic algorithms for generating voltage at the output of a frequency converter without feedback: scalar and spatial-vector pulse-width modulation and computational algorithms for voltage formation, as well as a comparative analysis of the spectra and the nonsinusoidality coefficient at comparable switching frequencies of power switches, performed both analytically, which gives an idea of the principles of forming the voltage spectrum, and by modeling processes in MATLAB/Simulink.

中文翻译：

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两电平变频器无反馈脉宽调制控制基本算法的频谱分析

摘要

根据“变频器-交流电动机”方案构造的变频电驱动广泛应用于现代技术和各种车辆的电驱动系统。目前，已经开发了许多调制变频器输出电压的方法，以使其形状更接近具有最低损耗的正弦波形。由于根据手头的任务优先考虑电压调制的不同特性，因此有必要了解在变频器输出端生成电压的主要算法的优缺点。大功率电力驱动系统的一个特点是不能使用变频器功率开关的高开关频率，这使得在使用特定方法时有必要了解电压谱的形成规律。本文考虑了在无反馈的变频器输出端生成电压的基本算法：标量和空间矢量脉宽调制以及电压形成的计算算法，以及在可比条件下对频谱和非正弦系数的比较分析。电源开关的开关频率，通过分析进行，它给出了形成电压谱的原理的概念，并通过在 MATLAB/Simulink 中建模过程。