三相PWM整流器的研究

【作者】 徐小品；

【导师】 黄进；

【作者基本信息】 浙江大学 ， 电机与电器， 2004， 硕士

【摘要】 传统的整流装置是电网污染的主要来源，三相电压型PWM整流器具有输出电压恒定、能实现单位功率因数运行的特点，甚至可以实现电能回馈电网。本文主要研究了三相电压型PWM整流器，内容包括下列方面：原理、拓扑结构、数学模型、控制策略和硬件实现。建立数学模型是研究三相PWM整流器的有效手段。分别在ABC静止坐标系、αβ静止坐标系和dq旋转坐标系中建立了低频和高频数学模型。本文主要对电压矢量定向控制和直接功率控制这两种关于PWM整流器的控制策略进行了研究。 电压矢量定向控制包括间接电流控制和直接电流控制，本文分别介绍了它们的原理。关于直接电流控制，建立了它的仿真模型，并介绍了数字化实现的方法。由于电网电压的谐波会恶化PWM整流器的工作性能，所以研究了改良的方法，并进行了实验验证。 直接功率控制方法的主要特点是结构简单、动态响应快、抗干扰性能好。本文介绍了瞬时功率的概念、直接功率控制的原理和电压矢量选择的方法。由于传统的开关状态表是引起无功功率控制效果差的主要原因，所以提出了改造开关状态表的方法。仿真和实验结果验证了此方法的有效性。最后，对电压矢量定向控制策略和直流功率控制策略作了比较研究。 关于硬件方面，介绍了主电路LC参数的计算方法、二阶有源滤波的设计方法、DSP2407的主要功能、IPM的驱动与保护。更多还原

【Abstract】 The conventional rectifiers produce harmonic problem in power system. While three-phase PWM voltage source rectifiers (VSR) can provide constant dc bus voltage and get low harmonic distortion of input current. It also has line power feedback capability. This paper mainly introduces three-phase VSR, including its principle, the topology, the mathematical model, the control strategies, and its hardware. The mathematical model of VSR is the essential means to investigate the VSR. Low frequency models and high frequency models are set up in ABC coordinate, α β coordinate, and dq coordinate, respectively. This paper focuses on two control strategies, one is voltage-oriented control (VOC), and the other is direct power control (DPC).Method of VOC includes indirect current control and direct current control, and their principles are introduced. This paper sets up a simulation model and presents a method of digital realization. A experiment about direct current control is done, and we find that the harmonics of line voltage deeply affect the distortion of input current. In order to weaken the distortion of input current, several practical means are presented.The advantages of DTC are simple structure, fast dynamic response, and the ability to resist disturbance. The concept of instantaneous power, the principle of DTC, and the method of selection of voltage vector are presented. When we use the conventional switching-table, the reactive power of system has uncontrollable region, and the input current is affected also. So a new type of switching-table is set up, and it is proved to be effective by experiment. At last, this paper compares these two methods: VOC and DTC.Moreover, the design of inductance and capacitance in VSR, the main function about DSP2407, the design of two-order active filter, and the using of intelligent power module (IPM) are introduced in this paper.更多还原