PWM逆变器驱动异步电机系统的共模电压研究

发布时间：2018-05-23 13:33

本文选题：共模电压 + PWM逆变器　；参考：《西南交通大学》2014年硕士论文

【摘要】：随着高频电力电子开关广泛应用于铁路机车牵引系统,在提升电机控制性能的同时也给牵引系统带来了负面效应。由于铁路机车牵引系统中的PWM逆变器的瞬时输出三相电压是不对称的,就会在牵引系统中产生共模电压,并且在异步电机系统中产生轴电压、轴电流等负面效应,严重影响了牵引系统的安全性和可靠性。因此,研究共模电压的形成机理、影响过程和抑制策略,对提升铁路机车牵引系统的安全性和可靠性有重要意义。本文首先会对PWM逆变器的工作原理和输出共模电压进行分析研究,了解共模电压的相关特性。之后对异步电机的基本工作原理、结构进行研究,在此基础上分析异步电机共模模型和共模电压对异步电机的影响,特别对轴电压的产生原理和轴电流的流通路径进行详细分析研究。然后在PWM逆变器和异步电机分析研究的基础上,提出共模电压的抑制策略,主要包括硬件策略和软件策略两方面,并就抑制原理进行分析。最后结合PWM逆变器驱动异步电机系统的理论分析,利用Matlab/Simulink仿真软件,建立驱动系统仿真模型,首先研究SPWM调制参数对共模电压、轴电压、dvldt电流和EDM电流的影响；然后研究直流侧供电模式和滤波器对共模电压、轴电压和轴电流的影响；最后研究SVPWM控制、NZPWM控制和直接转矩控制(DTC)对共模电压、轴电压和轴电流的影响。通过理论研究和仿真分析可以得出,共模电压硬件抑制策略有一定的优势,但是并没有从根本上消除共模电压,不仅增加了系统的复杂程度,而且相关硬件成本较高,通用性差,因此其性价比较低；而根据基于控制策略来抑制共模电压的分析研究可知,软件抑制策略不需格外增加硬件结构,而且投入低,通用性较好,基本上能满足机车牵引系统中共模电压抑制的要求。如果将硬件和软件抑制策略的优势相结合,能以最小的成本达到最好的效果。
[Abstract]:With the high frequency power electronic switch widely used in the traction system of railway locomotive, it not only improves the control performance of the motor, but also brings negative effects to the traction system. Because the instantaneous output three-phase voltage of PWM inverter in traction system of railway locomotive is asymmetrical, common mode voltage will be produced in traction system, and negative effects such as shaft voltage, shaft current and so on will be produced in asynchronous motor system. It seriously affects the safety and reliability of traction system. Therefore, it is of great significance to study the formation mechanism, influence process and suppression strategy of common-mode voltage for improving the safety and reliability of railway locomotive traction system. In this paper, the working principle and output common-mode voltage of PWM inverter are analyzed and studied firstly, and the related characteristics of common-mode voltage are understood. Then, the basic working principle and structure of asynchronous motor are studied, and the influence of common-mode model and common-mode voltage on asynchronous motor is analyzed. In particular, the generation principle of axis voltage and the flow path of axis current are analyzed in detail. Then, based on the analysis of PWM inverter and asynchronous motor, the common mode voltage suppression strategy is proposed, including hardware strategy and software strategy, and the suppression principle is analyzed. Finally, based on the theoretical analysis of the PWM inverter drive asynchronous motor system, the simulation model of the drive system is established by using the Matlab/Simulink simulation software. Firstly, the influence of the SPWM modulation parameters on the common-mode voltage, axis voltage, dvldt current and EDM current is studied. Then the influence of DC power supply mode and filter on common-mode voltage, axial voltage and axial current is studied. Finally, the influence of SVPWM control and direct torque control on common-mode voltage, axial voltage and axial current is studied. Through theoretical research and simulation analysis, it can be concluded that the common mode voltage hardware suppression strategy has some advantages, but it does not eliminate the common mode voltage fundamentally, which not only increases the complexity of the system, but also has high hardware cost. Because of its poor generality, its performance / price ratio is low. According to the analysis and research of the control strategy to suppress common-mode voltage, the software suppression strategy does not need extra hardware structure, and has low investment and good versatility. Basically can meet the locomotive traction system common mode voltage suppression requirements. If the advantages of hardware and software suppression strategies are combined, the best results can be achieved at minimal cost.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM343

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