【作者】 桂红云；

【导师】 吕征宇；

【作者基本信息】 浙江大学 ， 电力电子与电力传动， 2005， 硕士

【摘要】 多电平变换器是近年来电力电子领域中高压大功率应用场合研究的一个热点,这种变换器用容量小的器件输出高容量、高质量的电能,因此在中高压变频调速、交流柔性输电系统等场合得到了广泛的关注。 作为今后进一步研究的基础,本文首先在第一、二章综述了目前多电平技术发展的现状、总结和比较了多电平变换器各种基本的控制策略和拓扑结构特点,并讨论了多电平变换器的五类相关技术发展对多电平技术研究的影响;本文在第三章中讨论了双DSP的数控开发平台和三电平变频调速装置的硬件电路,为进一步实验研究三电平空间矢量控制和消谐波控制策略打下基础 在第四章中,在详述三电平SVPWM原理的基础之上,详尽地研究二极管箝位型三电平变换器中点电位不平衡的原因;定性和定量的研究了四类电压空间矢量对中点电位的影响;介绍了一种求解三电平空间矢量等效调制波的方法;并基于控制自由度和开关频率优化思想,提出并讨论了三电平中母线箝位SVPWM;最后提出了一种基于检测直流侧电压和三相输出电流合理选择控制因子的滞环SVPWM方法。在第五章中用仿真和实验的方法研究了上述两种空间矢量控制策略的特点。仿真和实验结果表明母线箝位SVPWM方法开关次数比普通的SVPWM减少33%,另外不同的母线箝位策略对中点电位的影响不同,这也为研究中点电位问题提出了一种方法;实验和仿真结果表明基于控制因子滞环SVPWM方法可以很好平衡中点电位。 在第六章中介绍了选择性消谐波两种PWM方法原理及其方程,并讨论了两种典型求解非线性超越方程的方法,最后通过实验和仿真结果验证了两种方法求解的正确性和SHEPWM方法的特点。 随着高速数字处理器、高压大容量的功率器件技术、光纤传感和通信技术、分布式能源系统技术、热管理技术等多电平相关技术的进一步发展和多电平控制策略研究进一步深入,多电平技术必将会得到更广泛的应用更多还原

【Abstract】 During recent years, multi-level inverter has been widely researched in high power level application with high voltage output. Power energy with characteristic of high capacity and high quality can be achieved by this type of inverter, in which relatively small-capability and low-voltage switches are adopted. So this technique has been widely concentrated in such application as medium-high voltage transducer and Flexible AC Transmission SystemBeing the basis of further research, status quo of multilevel technique is summarized in chapter 1, and five interrelating technologies, which are respective high speed DSP, power switch, optical isolation and communication skills, distributed power supply skills, heat management technology and influence development of the multi-level, are specified as well. In chapter 2, four basic topologies of multilevel and several control strategies are analyzed in detail and compared. In chapter 3, the hardware configuration of three level inverter and control flat of dual-DSP are discussed.In chapter 4, the principle of the three-level SVPWM is specified and consequently, the cause of unbalance of the neutral-point voltage is detailedly analyzed. The affects on the neutral point voltage of four types of voltage space vectors are debated qualitatively and quantificationally. A method of generating the equivalent modulating waveform of SVPWM is put forward. On the basis of freedom degree control and switch frequency optimization, five types of bus clamped SVPWM are proposed, correspondingly, the switch sequences and application are analyzed. Finally, a SVPWM control strategy, which can balance the neutral point voltage by changing the control factor on the basis of judging the DC Voltage of two capacitors and the directions of three phase output current, is presented. In chapter 5, achievement of the SVPWM driving signal by using the tool of SIMULINK and DSP is discussed in detail. The operation characteristic of bus clamped SVPWM, which has no change in some phase switching status during one period and the total switching times can be reduced by 33% compared with usual SVPWM technique. In addition, different types of CSVPWM results in different affects on neutral point voltage, which affords a method to solve the problem of neutral-point voltage unbalance. The strategy of changing control factor is illustrated as an example to solve the problem of the unbalance of the neutral-point voltage. Both experimental and simulation results verify the availability of this control strategy.In chapter 6, the principle of two typical SHEPWM methods is discussed and two methods for solving the nonlinear transcending equation are discussed and compared in detail. The results of simulation and experiment verify the validity of the two methods and characteristic of SHEPWM control strategy.With the development of the further research on multi-level technology and the development of DSP skills, high-capacity and high-voltage switch skills, optical communication and isolation technology, and etc, the multi-level inverter will be further widely used.更多还原