基于DSP的三电平变频调速系统的研究与设计

发布时间：2018-10-29 22:46

【摘要】：能源短缺、环境污染是当今世界人类面临的共同难题,我国在此大环境下提出了“两个替代”,即清洁替代和电能替代,而在电能消费中尤以高压大容量电动机为主。三电平逆变器开关管承受的电压应力为直流侧电压的一半,因此广泛应用于高压大容量交流变频调速领域,这在很大程度上能够节约电能、改善环境。本文在分析多电平变换器拓扑结构的基础上,重点围绕三电平变频器矢量控制原理和三电平逆变器的SVPWM调制算法展开研究。论文以异步电机在各坐标系下的数学模型为基础,分析了按转子磁场定向的异步电机矢量控制原理和基于全阶状态观测器的转速估算方法;研究了三电平逆变器的SVPWM调制算法,重点分析了基于α～β坐标系的SVPWM调制算法和基于60°坐标系的SVPWM调制算法。由于60°坐标系下的SVPWM算法更易于实现数字控制,因而确定采用这种方法作为三电平逆变器的调制算法。同时分析了引起三电平逆变器中点电位偏移的原因,给出了控制中点电位偏移的方法,并在软件算法基础上结合硬件来控制中点电位的偏移。论文搭建了三电平矢量控制系统仿真平台,对三电平变频调速系统进行了仿真验证,详细设计各个仿真模块,获得了仿真波形。仿真结果表明60°坐标系下SVPWM算法是正确的,硬件结合软件控制中点电位平衡算法降低了中点电压的波动范围,改善了系统性能。论文以TMS320F28335DSP为控制核心,搭建了三电平变频调速系统的实验验证平台,设计了电路参数,并在CCS 5.5环境下完成系统的软件设计,完成了系统的整体调试,获得了实验波形和实验结果。实验结果和仿真结果一致,表明了理论分析的正确性和系统设计的可行性。
[Abstract]:Energy shortage and environmental pollution are the common problems faced by human beings in the world today. In this environment, our country has put forward "two alternatives", namely, clean substitution and electric power substitution, especially high-voltage and large-capacity electric motors in electric energy consumption. The voltage stress of the three-level inverter switch is half of that of the DC side voltage, so it is widely used in the field of high voltage and large capacity AC frequency conversion speed regulation, which can save electric energy and improve the environment to a great extent. On the basis of analyzing the topology of multilevel converter, this paper focuses on the principle of vector control of three-level inverter and the SVPWM modulation algorithm of three-level inverter. Based on the mathematical models of induction motor in various coordinate systems, the vector control principle of induction motor based on rotor flux orientation and the method of speed estimation based on full order state observer are analyzed in this paper. The SVPWM modulation algorithm of three-level inverter is studied. The SVPWM modulation algorithm based on 伪 ~ 尾 coordinate system and the SVPWM modulation algorithm based on 60 掳coordinate system are analyzed. Because the SVPWM algorithm in 60 掳coordinate system is easier to realize digital control, this method is adopted as the modulation algorithm of three-level inverter. At the same time, the causes of neutral point potential shift in three-level inverter are analyzed, and the method of controlling neutral point potential migration is given. The offset of neutral point potential is controlled based on software algorithm and hardware. The simulation platform of three-level vector control system is built in this paper. The simulation verification of three-level variable-frequency speed regulation system is carried out. Each simulation module is designed in detail and the simulation waveform is obtained. The simulation results show that the SVPWM algorithm is correct in 60 掳coordinate system. The hardware and software control midpoint potential balance algorithm reduces the fluctuation range of midpoint voltage and improves the system performance. This paper takes TMS320F28335DSP as the control core, builds the experimental verification platform of the three-level variable-frequency speed regulation system, designs the circuit parameters, and completes the software design of the system under the environment of CCS 5.5, and completes the whole debugging of the system. Experimental waveforms and experimental results are obtained. The experimental results are consistent with the simulation results, which show the correctness of the theoretical analysis and the feasibility of the system design.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464;TM343

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