基于混合下垂控制的微电网自同步逆变器研究

发布时间：2018-06-07 01:10

本文选题：混合下垂控制 + 自同步逆变器　；参考：《东北大学》2014年硕士论文

【摘要】：近年来,微电网逆变器并网技术已成为研究的热点问题。目前,微电网逆变器的控制方式主要有单模式控制方式和双模式控制方式。单模式控制方法能够实现微电网并网和非计划离网的无缝切换,避免了双模式控制方式可能带来的模式切换失败的风险。传统的下垂控制能够实现单模式控制,但是由于下垂控制在孤岛运行时输出电压幅值、频率与额定值存在偏差,此时不允许直接并网操作,需要采用锁相环技术进行准同期控制。针对传统下垂控制存在的不足,本文在传统下垂控制的基础上提出了一种混合下垂自同步控制方法,能够使系统频率保持恒定,无需锁相环准同期控制过程可直接进行并网操作,完全实现“即插即用”。首先,本文介绍了不同坐标系下的下垂控制方法的实现,分析和比较三环下垂控制和单环下垂控制的特点,对逆变器准同期并网控制策略进行分析。其次,对本文所提出的自同步控制方法进行分析并运用小信号分析法建立微电网逆变器在并网和离网模型下的小信号模型,根据系统的状态空间方程画出系统的根轨迹图,并对系统的特征根轨迹进行分析,确定影响系统的主要控制参数,为选择系统控制参数提供理论依据。利用反步控制法对非线性辅助电压控制器进行设计,使得系统在并网和离网过程中能够平滑过渡,同时提高系统抗干扰能力。选择仿真系统的主回路及控制器相关参数,使用MATLAB/SIMULINK搭建系统仿真模型。对系统在独立、并联孤岛、并网、非计划性离网模式下运行以及负载突变等情况进行仿真,并对仿真结果进行分析,验证了自同步控制方法合理性和可行性。最后,为了进一步验证本文提出自同步控制方法的正确性,搭建了以DSP F2812为控制核心的实验平台,对整个系统的软件和硬件进行设计,使用C语言编写控制系统的软件程序。从系统实际运行时的数据和实验波形来看,所提出的自同步控制方法达到了很好的控制效果。
[Abstract]:In recent years, the grid connected technology of microgrid inverter has become a hot issue in the research. At present, the control mode of the micro grid inverter mainly includes single mode control mode and double mode control mode. The single mode control method can realize seamless switching of the micro grid connected with the unplanned off network, and avoid the possible mode of the dual mode control mode. The traditional droop control can realize single mode control, but due to the droop control output voltage amplitude in the island running, there is a deviation between the frequency and the rated value. At this time, the direct grid operation is not allowed, and the phase-locked loop technology is needed to carry out the quasi synchronization control. On the basis of the droop control, a hybrid droop self synchronization control method is proposed, which can keep the frequency of the system constant, without the need of the phase locked loop quasi synchronization control process to be directly connected to the network operation, and fully realize "plug and play". First, this paper introduces the implementation of the droop control method under different coordinate systems, analyzes and compares the three rings. The characteristics of droop control and single ring droop control are analyzed. Secondly, the control strategy of quasi synchronous grid is analyzed. Secondly, the self synchronization control method proposed in this paper is analyzed and small signal analysis is used to establish the small signal mode of the micro grid inverter under the grid connected and off network model, and the system is used to draw the system according to the state space equation. The root locus of the system is analyzed, the main control parameters of the system are determined, and the theoretical basis is provided to select the control parameters of the system. The backstepping control method is used to design the nonlinear auxiliary voltage controller, which makes the system smooth transition in the network and off network process, and improves the anti-interference of the system. Ability. Select the main circuit of the simulation system and the related parameters of the controller, build the system simulation model using MATLAB/SIMULINK, simulate the system in independent, parallel isolated island, grid, unplanned off network mode and load mutation, and analyze the simulation results, and verify the rationality and feasibility of the self synchronization control method. Finally, in order to further verify the correctness of the proposed self synchronization control method, an experimental platform with DSP F2812 as the control core is built, the software and hardware of the whole system are designed, and the software program of the control system is written in C language. From the data and experimental waveform of the actual operation of the system, the proposed self synchronization is proposed. The control method has achieved good control effect.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

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