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面向交流调速系统的随机空间矢量PWM技术的研究
A Randomized Voltage Space-Vector PWM Scheme for Converter-Fed Drive Systems
【作者】 段飞;
【导师】 张华曹;
【作者基本信息】 西安理工大学 , 微电子学与固体电子学, 2003, 硕士
【摘要】 作为交流传动系统中的一项关键技术,PWM(Pulse Width Modulation)技术在提高效率、降低能耗、减少污染等方面具有重大意义。针对交流调速装置中的噪声问题,论文研究了一种新兴的PWM技术---随机空间矢量PWM技术。 首先,论文通过归纳PWM技术的发展现状,论证了传统PWM技术的缺陷与不足,并提出问题的解决方向。 其次,通过比较现有随机PWM算法的优劣,以面向应用为导向,结合空间矢量PWM,选取最有利于数字化调制实现的随机空间矢量PWM算法;基于对现有随机PWM算法的分析评价,提出了新的随机调制算法。改进和优化随机数算法,构筑具有更充分独立性和周期性的随机型。 再次,通过仿真来验证算法的优越性。论文着重研究随机信号最重要的统计特性——功率谱密度,通过计算机仿真来比较分析不同PWM信号的功率谱特性。 最后,在系统环境中评价随机空间矢量PWM算法的有效性。 论文的主要工作包括: 1.提出一种基于电压空间矢量调制的随机PWM新算法,实现有限状态之间的随机转换,并能与提高开关频率有效结合。将这种两电平算法扩展到了三电平情况,发展了基于此方法的三电平随机空间矢量PWM算法。 2.改进传统的随机数算法,通过计算机程序仿真随机型的输出结果。 3.基于对随机空间矢量PWM算法及其功率谱密度的研究,开发出完整的空间矢量PWM仿真软件,通过VC++凋用MATLAB引擎函数库实现FFT(Fast Flourier Transformation)。 西安理工大学硕士学位论文 4.通过Simulink系统仿真和实验来验证随机空间矢量PWM的可行性,其中系统实验的核心工作为编制实现P删输出的单片机程序。
【Abstract】 Random Pulse Width Modulation (RPWM) techniques for voltage-controlled power electronic converters have been attracting an increased interest due to the unique effects of these techniques on the converter-supplied drive systems. In this paper, a feasibility study of the Random Space-Vector Pulse Width Modulation (PWM) scheme is reported aiming at the noise reduction by power inverters.First at all, the paper presents a synthetic review of the state of the art in PWM theory and practice, and take a direction to perfect the conventional PWM.Second, based on the space vector concept and the existing PWM techniques comparison, a new RPWM strategy is proposed and implemented. The new random modulation algorithms are developed both on the two level and three level inverters.Third, the algorithm simulations involving the power spectra are achieved by the computer program developed in this paper. As a result, the power spectra of the electromagnetic acoustic noise is spread to the wide band area and the wide band noise is much more comfortable and less annoying than the narrow band one.Last but not least, the simulated and experimental systematic output proves the validity of the Random Space Vector PWM, which is considered producing the input action of the system.The work covers the new algorithm investigation, the improvement of random number generation and the simulations coming on the PWM appearance, the power spectra, the random number generation model and the power system output. The PWM scheme has been executed in real time in a digital controller and its features have been experimentally confirmed.
- 【网络出版投稿人】 西安理工大学 【网络出版年期】2003年 02期
- 【分类号】TM921.5
- 【被引频次】2
- 【下载频次】321