摘要现代工业生产中,电力电子装置的大量应用带来谐波,其对电网产生了污染,影响了电能质量,降低了电网质量因数。
随着社会对绿色清洁能源的普遍要求,PWM整流技术开始被重视起来,并进行了相关的研究工作。
PWM整流器比起传统的整流器,具备诸多优点,例如输出的电压稳定,通过调控,输入电流达到正弦,功率因数可调整性强。
因此,电力电子行业比较关注对PWM整流器的研究。
常规的整流策略大多使用二极管整流或者相控整流,这两种整流方式存在着自身的缺陷,虽然能实现电能的调控,但是产生了无法消除的谐波,电力变换的电压利用率不高,能耗较大,引起发热,对电力电子的器件寿命造成影响。
PWM整流不同于传统的整流方式,它可以实现能量的双向流动,既可以工作在整流状态,作为负载的稳压电源,又可以从交流侧向交流侧通过逆变回馈能量。
本文针对电压型PWM整流器,研究其工作原理和控制策略,论述和研究的方向如下:首先,需要分析三相电压型PWM整流器的工作原理和状态,必须建立数学模型。
其次,通过对三相电压PWM整流器模型的研究,总结出其电流模式的控制方式,从控制原理、控制器参数、优缺点等方面对几种控制策略进行比较。
本文重点引入定频和双滞环结合的定频滞环控制算法,描述了其控制机理和实现方法。
定频滞环控制策略的控制方法是双滞环,对整流器交流侧线电流进行控制,通过内滞环的开关状态控制来减少高次谐波分量,通过外滞环的开关状态控制来加快电流响应速度,此种策略加强了电流的跟踪控制。
最后,结合对以上控制策略的理论研究,构建整流系统的实验平台,使定频滞环控制算法得以在实验平台上仿真,论证控制策略的合理性以及控制方式的可行性。
关键词:PWM整流器;空间电压矢量;电流滞环;固定开关频率;单位功率因数AbstractIn the modern industrial field, a large number of applications of electrical devices generates lots of harmonics, which may pollute grid, affect the quality of power, and reduce the power factor. With the increasing requirement of clear power in the whole society, PWM based converting technology has been taken more and more seriously. This phenomenon can be found in the related studies in the field of power conversion and transmission. Compared with the traditional converters, PWM rectifier has many advantages, such as, it has the stable output voltage, the sine-shaped input current. Besides, the power factor of PWM converter can be regulated between -1 to 1. Thus, the power electronics industry is more concerned with the study of PWM rectifiers than the traditional converter.Most conventional power conversion strategies apply diode based rectification and phase-controlled based rectification. These two rectification methods have the own defects. For example, although the energy regulation with these two methods can be realized, the harmonics cannot be eliminated obviously. Moreover, compared with the PWM rectification based method, the traditional converting method has the low DC voltage utilization efficiency during the power conversion, the larger power loss and tends to the extra heat, these demerits reduce the remaining life of the electronic device.Different from the traditional converting methods, PWM rectifier has an ability to realize the dual-direction energy flowing between the AC side and the DC side. This property makes the PWM rectifier can run in the AC / DC state, and also can work in the AC / DC state.This paper focuses on the control method for the voltage source based PWM rectifier, and first introduces the related working principle and the existing control strategy, the main content shows as follows,First, this paper presents the research object, the basics of PWM rectifier, the working states, and constructs the mathematical model of PWM rectifier.Second, according to the mathematical model of three-phase PWM rectifier, this paper concludes and compares the typical current based control strategies, from the controlling principle, critical parameters, advantages, and disadvantages. After that, this paper proposes a fixed frequency hysteresis control algorithm with fixed frequency and double hysteresis loops. This control strategy restrains the high harmonics through the switch state of the inner hysteresis loop and keeps the current response speed with the outer loop of voltage.At last, on the basis of the proposed control strategy, this paper sets up the experimental platform and verifies the proposed fixed frequency hysteresis control strategy.Keywords: PWM Rectifier; SVPWM; Current Hysteresis; Fixed Switching Frequency; Unit Power Factor目录摘要 (I)ABSTRACT (II)第一章绪论 (1)1.1研究背景与意义 (1)1.2国内外研究现状 (3)1.2.1 PWM整流器现状 (4)1.2.2 PWM整流器控制策略的发展现状 (6)1.3研究内容 (10)第二章 PWM整流器的控制原理分析及建立模型 (12)2.1PWM整流器的工作原理 (12)2.2PWM整流器的数学模型 (14)2.2.1 在三相静止坐标系下的数学模型 (14)2.2.2 在两相静止坐标系下的数学模型 (15)2.2.3 在两相旋转坐标系下的数学模型 (18)2.3本章小结 (20)第三章 PWM整流器的电流模式控制策略 (21)3.1传统电流模式控制策略 (21)3.1.1 滞环电流控制 (21)3.1.2 固定开关频率控制 (25)3.2定频滞环电流控制策略 (28)3.2.1 交流侧线电流解耦算法 (30)3.2.2 SVPWM及双滞环调节算法 (31)3.3仿真波形比较与分析 (33)3.4本章小结 (43)第四章设计PWM整流器软硬件系统 (44)4.1总体设计 (44)4.2主电路硬件设计 (44)4.2.1 主电路器件参数及其选取 (44)4.2.2 交流侧电感设计 (46)4.2.3 直流侧电容设计 (477)4.3基于DSP/TMS320F28335的控制电路硬件设计 (49)4.3.1 DSP/TMS320F28335处理器简介 (50)4.3.2 驱动电路 (51)4.3.3 电流检测电路 (52)4.3.4 输出电压检测电路 (55)4.4软件程序设计 (56)4.4.1 程序模块设计 (56)4.4.2 主程序设计 (56)4.4.3 中断服务子程序设计 (57)4.5SVPWM软件设计 (62)4.6实验结果 (63)4.7本章小结 (65)第五章结论 (66)5.1全文总结 (66)5.2研究展望 (677)参考文献 (68)致谢 (73)第一章 绪论第一章 绪论1.1 研究背景与意义在工业生产中已经越来越普遍地使用基于电力电子技术的电能转换设备,例如整流器、逆变器、变频器、励磁电源以及光伏发电设备等,通过运用这些电子设备,人们能更高效的开展工业生产活动,同时给人们的生活也带来很多方便。