【作者】 李云霞；

【导师】 曾毅；

【作者基本信息】 山东大学 ， 控制理论与控制工程， 2009， 硕士

【摘要】 在中高压大容量变频调速器和电力有源滤波器大量应用的促使下,多电平逆变器已成为当前电力电子技术中倍受人们关注的重要研究热点。围绕多电平逆变器,新型电路拓扑及相关控制策略层出不穷,无论从广度还是深度而言,多电平逆变技术研究都得到了极大的推动。然而在国内,却很少有具有自主知识产权的多电平逆变器产品,本文笔者则自行研发了基于独特控制策略的级联式多电平逆变器,并通过实验进行了验证。本文从拓扑和控制两个方面分别对多电平逆变器进行研究,以级联式多电平逆变器为主要研究对象,提出了具有针对性的非PWM控制方法。接着完成了三单元级联七电平逆变器单相系统的设计,并对级联式多电平逆变器进行了仿真,最后给出了单相系统的实验结果。具体工作内容如下:首先,分析了二极管钳位式、飞跨电容钳位式、级联式和层叠式多电平逆变电路的工作原理和优缺点,重点分析了多单元级联式逆变电路的工作原理,并针对其特点提出了新型非PWM的控制方式,大大降低了开关管的开关频率,避免了传统的PWM方式所造成的电网污染和电磁干扰。其次,在TMS320LF2407数字信号处理器的基础上,研制了一套基于DSP控制的非PWM级联式多电平逆变器的单相系统。主要包括主电路、系统的非PWM控制电路、优化的驱动电路以及缓冲电路的设计等。同时,基于非PWM的控制方式,利用MATLAB中的SIMULINK对级联式多电平逆变器进行了多单元叠加的仿真,得到了令人满意的仿真结果。最后,基于实际的硬件电路,对其进行联合调试,做了相关的实验,得到的实验结果与理论分析和仿真结果基本一致。实验结果表明本文设计的硬件实验平台及其控制策略是正确的,能够满足进一步研究的需要。更多还原

【Abstract】 As the promotion of high-voltage large-capacity frequency converter and active power filter to a large number of applications. Multilevel inverter has been becoming hot point in current power electronics technology due to people’s attention. Novel topologies and modulation strategies concerning multi-level converters are emerging continuously. As for as the width an depth are concerned, research on multilevel technique is advanced greatly.In the paper,we analyzed both the topology and the control schema of multilevel inverter. As cascaded multilevel inverter for the main study, we put forward the non-PWM control method. Then,we completed a single-phase system design of the three modules cascaded seven-level inverter, and did software simulation on cascaded multilevel inverter. At last, we got the experiment reasult of the single-phase system.In detail, the principle and features of several existing multilevel topologies are analyzed. Focused on analyzing cascaded multilevel inverter circuit working principle. And for its characteristics, a new type of non-PWM control mode was put forward, witch greatly reduced the switching frequency and avoided the power grid caused by pollution and electromagnetic interference of the traditional PWM mode.Based on the digital signal processor TMS320LF2407,we developed a cascaded multilevel converter experiment platform of non PWM. It mainly included the main circuit, the system of non-PWM control circuit, and the optimized drive circuit and the buffer circuit.Based on non-PWM control mode, doing software simulation on cascaded multilevel converter of multi-unit stack using SIMULINK of MATLAB.And got satisfactory simulation results.Based on the actual hardware circuit, doing the relevant experiments, the experimental results obtained with the theoretical analysis and simulation results are basically consistent. Experimental results show that the design hardware experimental platform and its control strategy is correct, and be able to meet the needs of furtherstudy.更多还原