【作者】 伍超；

【导师】 钟彦儒； 伍文俊；

【作者基本信息】 西安理工大学 ， 电力电子与电力传动， 2008， 硕士

【摘要】 为了消除不控整流,半控整流对电网造成的谐波污染,在整流器中引入PWM技术,使得整流器网侧电流正弦化,并且运行在单位功率因数下,从而减小了整流器对于电网的污染,而且可以将能量回馈电网,因此PWM整流器成为整流器研究的热点。本课题所研究的内容是三相三电平PWM整流器,其特点是适合中高电压等级的整流系统,或者调速系统。通过分析各种三电平拓扑结构以及控制方法,确定本课题为基于空间电压矢量调制的二极管箝位式三电平整流装置的研究,并通过仿真实验以及制作小功率样机,验证了方法的正确性。通过分析传统的基于θ和调制比m的空间电压矢量脉宽调制算法,推导出了基于V_α,V_β的空间电压矢量脉宽调制算法,该算法实现简单,只包括加法、减法、乘法等简单运算,有利于DSP2407的编程实现。根据仿真波形和实验波形,特别针对直流侧两电容电压平衡问题,提出了变比例因子中点平衡控制方法,在仿真实验以及在小功率样机中验证了控制方法的可行性、有效性。最后分析了中矢量对于三电平整流器直流侧中点的影响,提出了一种新的矢量调制策略,即通过大矢量合成中矢量,以及改善矢量合成区域的划分,较好的解决了直流侧中点平衡的问题,在仿真实验中通过和传统七段式方法对比,验证了本方案对中点平衡有着较强的调节能力。更多还原

【Abstract】 In order to reduce the harmonious pollution in power net caused by none control or half control rectifier, we introduce the PWM technique to rectifier to totally eliminate the harmonious pollution in power net, making current to sin wave at the AC side so as to be the state of unity power factor, furthermore, it can sent the energy to the power net. So the research in rectifier becomes hotspot.The content I research is three phase three level rectifier, which fit for commuting system or speed governing system of the middle of high voltage level. Through analyzing the three level topology and control method, the three phases three level diode-clamped rectifier based on the three level SVPWM is confirmed finally. It proved by simulation and practice on a small power set.By analyzing the traditional strategy based onθand modulation proportion m ,a new strategy based on V_α,V_βis proposed. The strategy is easy to practice which only content the simply operation, the addition, the subtraction and the multiplication. Quite fit for programming on DSP 2407.According to the waveform, specially, the issue about the balance of the two capacitances voltage is exists. The balance control by various proportion genes is proposed, validated by simulating and the experiment.Finally, through analyzing the neutral point at DC side influenced by the center vector, a new space vector modulation is proposed, the technique is radial state space vector modulation and improves the divisions of the area of vector composition and the issue is solved better which confirmed by the comparison between the two vector modulation simulating.更多还原