有源电力滤波器与光伏并网逆变器的统一控制研究

发布时间：2018-05-14 01:17

本文选题：有源电力滤波器 + 光伏并网逆变器　；参考：《太原理工大学》2016年硕士论文

【摘要】：在当前社会的不断进步中,化石能源日益短缺与环境不断恶化同时困扰着我们。在这种情况下,具有清洁、不竭、量大等优势的太阳能受到了研究学者的青睐。然而太阳能不稳定、光伏发电并网设备造价高、利用率低等因素制约着光伏发电的推广与应用。另一方面,电力电子技术迅速发展,各种非线性设备在方便人们生活的同时,将大量的谐波、无功电流分量注入电力系统,谐波无功在降低电能效率的同时,还具有一定的安全隐患,电力系统的电能质量随即也成为另一个亟待解决的问题。作为一种主动的谐波、无功滤除装置,有源电力滤波器(APF)受到了各研究所及高校的重视。经过多年的研究,APF的理论基础已日趋完善,现阶段主要是控制方法的优化,同时APF也面临着价格昂贵、附带功能少等发展阻碍。本文首先分析了光伏并网逆变器与APF系统各自的优缺点、发展中遇到的问题和发展前景、工作原理及结构特点,探究了APF与光伏并网逆变统一控制的可能性及重大意义,提出了一种APF与光伏并网逆变器的统一控制系统。结合基于瞬时无功功率理论的ip-iq谐波检测法,分析了统一控制系统的指令电流求取方法。对指令电流求取环节中的锁相环(PLL)原理进行了分析,介绍了锁相环的软件实现方法,弥补了以往采用过零检测法实现锁相的缺陷,即单个周期内频率改变无法预测。针对指令电流的跟踪控制,采用滞环SVPWM的控制策略,即根据误差电流与参考电压的空间矢量位置关系,选择最优输出电压矢量,限制误差电流在容许范围之内,达到电流跟踪控制的目的,该策略具有实现简单、跟踪性能良好、开关损耗小等优势。另外,简要介绍了直流侧电压的比例积分控制方法。利用MATLAB软件中的仿真组件SIMULINK,搭建了系统仿真模型,其中主要包括指令电流求取模块、电流跟踪控制模块及二极管整流桥带阻感负载的主电路等几个部分。分别在单独APF状态、APF与光伏并网逆变器统一控制状态下做了仿真,仿真结果验证了本文所述系统的正确性。以DSP2812为控制核心,搭建了统一控制系统的硬件实验平台,主要包括信号检测调理电路、故障处理电路、保护电路、移相电路及二极管整流桥带阻感负载的主电路等几个部分,详细说明并给出了各个部分的电路结构图。通过编写软件,在DSP内部实现软件锁相环计算、指令电流的检测及电流的跟踪控制等几个部分,对各个部分的软件流程图进行了介绍,最终得出的实验结果表明了本文所提出的统一控制系统的可行性。
[Abstract]:With the development of our society, the shortage of fossil energy and the deterioration of environment are perplexing us at the same time. In this case, the advantages of clean, inexhaustible, large amount of solar energy has been favored by researchers. However, the instability of solar energy, the high cost of photovoltaic grid connection equipment, low utilization rate and other factors restrict the promotion and application of photovoltaic power generation. On the other hand, with the rapid development of power electronics technology, a lot of harmonic and reactive current components are injected into the power system while all kinds of nonlinear devices are convenient for people to live, and the harmonic reactive power reduces the power efficiency at the same time. The power quality of power system has become another problem to be solved. As a kind of active harmonic, reactive power filter (APFF) has been paid more and more attention by research institutes and universities. After many years of research, the theoretical basis of APF has become more and more perfect. At the present stage, it is mainly the optimization of control methods. At the same time, APF is also faced with the development obstacles such as high price, few incidental functions and so on. In this paper, the advantages and disadvantages of photovoltaic grid-connected inverter and APF system, the problems encountered in the development, the working principle and structure characteristics, and the possibility and significance of unified control of APF and photovoltaic grid-connected inverter are analyzed in this paper. A unified control system of APF and photovoltaic grid-connected inverter is proposed. Combined with the ip-iq harmonic detection method based on the instantaneous reactive power theory, the method of obtaining the instruction current of the unified control system is analyzed. The principle of PLL is analyzed, and the software implementation method of PLL is introduced, which makes up for the defect of zero crossing detection in the past, that is, the frequency change in a single cycle can not be predicted. Aiming at the tracking control of instruction current, the control strategy of hysteresis loop SVPWM is adopted, that is, according to the space vector position relation of error current and reference voltage, the optimal output voltage vector is selected, which limits the error current within the allowable range. To achieve the purpose of current tracking control, the strategy has the advantages of simple implementation, good tracking performance and low switching loss. In addition, the proportional integral control method of DC-side voltage is briefly introduced. The simulation model of the system is built by using Simulink, which is a simulation component of MATLAB software. It mainly includes the command current acquisition module, the current tracking control module and the main circuit of diode rectifier bridge band-stop load. The simulation results show that the proposed system is correct in the case of a single APF state and a photovoltaic grid-connected inverter. Taking DSP2812 as the control core, the hardware experiment platform of the unified control system is built, which mainly includes signal detection and conditioning circuit, fault processing circuit, protection circuit, phase-shifting circuit and main circuit of diode rectifier bridge stop-inductance load, etc. The circuit structure of each part is explained and given in detail. By writing the software, the software phase locked loop calculation, the detection of the instruction current and the tracking control of the current are realized in DSP. The software flow chart of each part is introduced. Finally, the experimental results show the feasibility of the unified control system proposed in this paper.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM761.12;TM464

【相似文献】