三相电压型高功率因数PWM整流器的设计

发布时间：2018-06-06 11:12

本文选题：PWM整流器 + 三相电压型半桥电路　；参考：《华南理工大学》2014年硕士论文

【摘要】：随着半导体功率开关器件的性能不断的提升，特别是全控型开关器件的性能的提升，，使得电力电子设备上在保证功率密度和整机效率的同时，整机的功率等级也越来越高。众所周知，由二极管组成的不可控整流电路和相控式整流电路虽然技术已经很成熟、控制简单、价格便宜，但是它们带来的大量谐波和无功功率会对电网产生“污染”。使用全控型开关器件和应用PWM(Pulse Width Modulation，脉宽调制)技术的PWM整流器可以实现网侧电流的正弦化，也能对谐波进行一定地抑制，甚至能够对无功功率进行灵活地调节。功率因数是PWM整流器的应用指标之一。PWM整流器不仅能够稳定其直流输出电压，并且能够实现网侧的功率因数为1（当功率因数为1时，PWM整流器处于单位功率因数整流状态；当功率因数为-1时，处于单位功率因数逆变状态。），也就是实现了电能的双向传输。高功率因数的PWM整流器可以从根本上对电网减少污染。本文主要研究基于三相电压型半桥结构的PWM整流器的高功率因数控制策略。三相电压型PWM整流器是一个强非线性、时变的耦合系统，为使其整流输出具有优良的性能，其控制系统通常采用电压外环和电流内环的双环控制策略。电压外环是为了对PWM整流器的直流侧输出电压稳定而进行控制。电流内环为实现PWM整流器网侧具有单位功率因数而对网侧电流进行控制。为了方便电流内环的控制，通常对三相电流进行坐标变换使它们由交流量变成直流量，即使这样但它们还是存在着变量的耦合，为此采用PI控制器（比例调节和积分调节）的前馈解耦控制策略，采用PI控制还可以取得无静差调节。由于通过坐标变换后的两个电流值是PWM整流器网侧吸收（或者发出）的有功功率和无功功率的直接表现，所以，如果要PWM整流器取得较好的动、静态性能，关键在于电流内环的控制设计。为此，可以利用最优控制理论寻求一种电流内环的时间最优控制策略，构建电流内环的控制方程。本文首先对PWM的研究背景及意义进行了简单的介绍，并对PWM整流器常用的拓扑结构进行了归纳和比较。由于本文主要对三相电压型PWM整流器进行研究，所以详细地分析了其工作原理和简单介绍了其主要的输入输出的电压电流波形，然后对其进行数学模型的建立，包括一般数学模型和在两相旋转dq坐标系下的数学模型。简单介绍了PWM整流器的控制策略，然后对电流内环加电压外环的双环控制策略进行了详细地介绍，包括对电流内环的时间最优控制策略进行了介绍，接着介绍了由空间矢量调制生成开关信号的方式，对两者的进行结合就完成了整个系统的控制电路。根据PWM整流器的相关理论，在电力电子仿真软件PSIM里进行了三相电压型PWM整流器仿真模型的搭建，并对相关控制算法进行验证。根据三相电压型PWM整流器仿真模型搭建了实验平台，对实验平台的搭建进行了详细地介绍，对仿真模型进行了验证。
[Abstract]:With the continuous improvement of the performance of the semiconductor power switch devices, especially the performance of the fully controlled switch devices, the power electronic equipment is also increasing the power level of the whole machine while guaranteeing the power density and the efficiency of the whole machine. As we all know, the uncontrollable rectifier circuit and the phase controlled rectifier circuit formed by the diode group are well known. But the technology is already very mature, easy to control and cheap, but the great amount of harmonic and reactive power that they bring will cause "pollution" to the power grid. Using full control switch device and the PWM rectifier using PWM (Pulse Width Modulation, pulse width modulation) technology can realize the sinusoidal current of the network side, and can also restrain the harmonic. It can even adjust the reactive power flexibly.
The power factor is one of the application indicators of the PWM rectifier..PWM rectifier can not only stabilize its DC output voltage, but also realize the power factor of the network side to 1 (when the power factor is 1, the PWM rectifier is in a unit power factor rectifying state; when the power factor is -1, it is in the state of the unit power factor inverter.) that is, the realization of the power factor. The bidirectional transmission of electric energy. PWM rectifier with high power factor can fundamentally reduce pollution to the power grid.
This paper mainly studies the high power factor control strategy of PWM rectifier based on three phase voltage half bridge structure.
The three-phase voltage type PWM rectifier is a strongly nonlinear, time-varying coupling system. In order to make its rectifying output with excellent performance, the control system usually adopts the double loop control strategy of the external voltage loop and the current inner loop. The voltage outer loop is designed to control the DC side output voltage stability of the PWM rectifier. The current inner loop is to realize the PWM whole. The network side has a unit power factor to control the current side current. In order to facilitate the control of the current inner loop, the three-phase current is usually transformed from the alternating current to the direct flow, even though they still have the coupling of the variables, so the feedforward decoupling control of the PI controller (proportional and integral adjustment) is used. The strategy of PI control can also achieve no static adjustment. Since the two current values after the coordinate transformation are the direct performance of the active power and reactive power of the PWM Rectifier's net side absorption (or emit), the key lies in the control design of the inner loop if the PWM rectifier is to get better dynamic and static energy. The optimal control theory is used to find a time optimal control strategy for the current inner loop, and the control equation of the current inner loop is constructed.
In this paper, the background and significance of PWM are briefly introduced, and the common topology of PWM rectifier is summarized and compared. Because this paper mainly studies the three-phase voltage type PWM rectifier, the principle of its work and the voltage and current waveform of its main input and output are analyzed in detail. After that, the mathematical model is established, including the general mathematical model and the mathematical model in the two phase rotating dq coordinate system. The control strategy of the PWM rectifier is briefly introduced. Then the double loop control strategy of the current loop and the external loop is introduced in detail, including the time optimal control strategy of the current inner loop. Then it introduces the way of generating switch signals from space vector modulation, and completes the control circuit of the whole system by combining them.
According to the related theory of the PWM rectifier, the simulation model of the three-phase voltage type PWM rectifier is built in the power electronic simulation software PSIM, and the related control algorithms are verified.
The experimental platform is built according to the simulation model of three-phase voltage source PWM rectifier, and the construction of the experimental platform is introduced in detail, and the simulation model is verified.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM461

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