分布式发电系统并网逆变器控制策略研究

发布时间：2018-04-29 05:04

本文选题：分布式发电系统 + 并网逆变器　；参考：《燕山大学》2014年硕士论文

【摘要】：可再生能源用作发电源的分布式发电已成为当今能源产业的发展方向，作为电网与分布式发电源之间的桥梁，逆变器成为了研究的热点。本文以三相电压源型并网逆变器系统为研究对象，研究了分布式发电系统并网运行状态下的功率控制问题和直流母线电压的控制问题。通过控制并网逆变器的输出电流来控制其输出功率，实现了对有功和无功功率的解耦控制，满足了电网的功率需求。首先，介绍了电压源型逆变器的工作原理与数学描述。分析了并网逆变器系统的结构组成，建立了系统在不同坐标系下的数学模型，为后续章节的研究做好铺垫。其次，针对传统三相电压源型并网逆变器系统的非线性特性以及参数摄动、外部干扰带来的不确定性，，采用自适应控制策略。应用自适应Backstepping技术设计了具有干扰抑制功能的自适应控制器，对逆变器的输出功率进行控制，实现了系统的单位功率因数运行，同时保证了直流母线电压的平稳。理论分析与仿真实验均验证了所采用的控制策略的有效性。最后，研究交流电网功率需求发生变化时的功率跟踪控制问题。采用LCL型并网逆变器拓扑结构，考虑到系统阶次高的特点，运用Backstepping递归控制思想推导控制律，同时针对运行过程中系统的参数变化等不确定性因素，采用鲁棒控制策略设计控制器。在控制并网有功功率的同时实现了对电网的无功功率的补偿控制，保证了系统的稳定运行。仿真研究表明所采取的控制策略可以实现对逆变器输出功率的有效控制，并且克服了系统参数变化对系统性能的影响。
[Abstract]:Distributed generation of renewable energy as power generation has become the development direction of the energy industry. As a bridge between power grid and distributed generation, inverter has become a hot research topic. In this paper, a three-phase voltage source grid-connected inverter system is studied. The power control problem and the DC bus voltage control problem are studied under the condition of grid-connected operation of distributed generation system. The output power of grid-connected inverter is controlled by controlling the output current of grid-connected inverter. The decoupling control of active and reactive power is realized and the power demand of power grid is satisfied. Firstly, the working principle and mathematical description of voltage source inverter are introduced. The structure of grid-connected inverter system is analyzed, and the mathematical models of the system in different coordinate systems are established, which pave the way for the study of the following chapters. Secondly, the adaptive control strategy is adopted to solve the nonlinear characteristics of traditional three-phase voltage source grid-connected inverter system and the uncertainty caused by parameter perturbation and external disturbance. An adaptive controller with interference suppression function is designed by using adaptive Backstepping technology. The output power of the inverter is controlled. The unit power factor of the system is realized and the DC bus voltage is stable. The effectiveness of the proposed control strategy is verified by theoretical analysis and simulation experiments. Finally, the power tracking control problem is studied when the power demand of AC power system changes. Using the topology structure of LCL grid-connected inverter and considering the characteristic of high order of the system, the control law is deduced by using the idea of Backstepping recursive control. At the same time, the uncertain factors such as the change of system parameters during operation are considered. A robust control strategy is used to design the controller. The reactive power compensation control is realized while the active power connected to the grid is controlled, which ensures the stable operation of the system. Simulation results show that the proposed control strategy can effectively control the output power of the inverter and overcome the influence of the system parameters on the system performance.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

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