微电网平滑切换控制及孤岛检测方法研究

发布时间：2018-03-31 10:34

本文选题：含光储能微电网　切入点：比例谐振控制　出处：《西南交通大学》2014年硕士论文

【摘要】：微电网是实现新能源利用的有效途径,微电网运行控制研究对提高新能源的利用率,增强微电网的灵活性和稳定性有着重要意义。微电网平滑切换控制和孤岛检测方法是微电网控制技术的重要组成部分,本文以含光储能系统的微电网为研究对象,对微电网的平滑切换控制策略和孤岛检测方法进行研究。首先,分析了光伏电源和蓄电池的控制方法和数学模型,利用MATLAB/Simulink搭建了光伏电源控制模型和蓄电池充放电控制电路模型,实现了光伏电源的最大功率跟踪和蓄电池的恒电压充放电控制。其次,在分析微电网的运行控制方式及控制策略的基础上,研究了逆变器的控制电路和数学模型。将比例谐振控制器引入到电流内环控制中,使控制更简单、抗电网电压干扰能力更强,消除了坐标变换和功率解耦控制。然后,利用含光储能系统的微电网对微电网平滑切换控制进行研究,引入状态跟随器有效改善了控制切换过程。对切换控制器和切负荷的先后顺序进行了仿真研究,将3区域切负荷控制策略引入到含光储能系统的微电网,仿真结果表明该控制策略可有效降低切负荷带来的暂态振荡。最后,在分析孤岛检测原理的基础上,改进了有功-电压孤岛检测算法,设置逆变器输出有功功率为公共耦合点处电压与电网额定电压差值的正反馈函数。并与无功-频率孤岛检测算法进行了对比研究,对检测原理进行了分析并设计了反馈参数,最后进行了仿真验证。理论分析和仿真验证表明,采用比例谐振电流内环控制器的光伏电源具有较强的抗电网电压干扰能力；状态跟随器和3区域切负荷控制可以有效降低微电网切换过程的暂态振荡；改进的有功-电压正反馈扰动孤岛检测算法检测速度快、对并网电能质量影响小、没有检测盲区,本文的研究成果对微电网运行控制有一定的参考价值。
[Abstract]:Microgrid is an effective way to realize the utilization of new energy. It is of great significance to enhance the flexibility and stability of microgrid. Smooth switching control and islanding detection are important parts of microgrid control technology. The smooth switching control strategy and islanding detection method of microgrid are studied. Firstly, the control methods and mathematical models of photovoltaic power supply and battery are analyzed, and the control model of photovoltaic power supply and battery charge and discharge control circuit are built by using MATLAB/Simulink. The maximum power tracking of photovoltaic power supply and the constant voltage charge and discharge control of battery are realized. Secondly, on the basis of analyzing the operation control mode and control strategy of microgrid, the control circuit and mathematical model of inverter are studied. The proportional resonant controller is introduced into the current inner loop control to make the control simpler. The ability of resisting grid voltage interference is stronger, eliminating coordinate transformation and power decoupling control. Then, the smooth switching control of microgrid is studied by using the microgrid with optical energy storage system, and the switching process is improved effectively by introducing the state follower. The switching controller and the sequence of load shedding are simulated. The three-region load shedding control strategy is introduced to the micro-grid with optical energy storage system. The simulation results show that the proposed control strategy can effectively reduce the transient oscillation caused by the shedding load. Finally, on the basis of analyzing the principle of islanding detection, the active power-voltage islanding detection algorithm is improved. The output active power of the inverter is the positive feedback function of the difference between the voltage at the common coupling point and the rated voltage of the power network. The detection principle is analyzed and the feedback parameters are designed and compared with the reactive power-frequency islanding detection algorithm. Finally, the simulation is carried out. The theoretical analysis and simulation results show that the photovoltaic power supply with proportional resonant current inner loop controller has strong resistance to grid voltage interference. The state follower and 3-region load shedding control can effectively reduce the transient oscillation in the switching process of microgrid, and the improved active power-voltage positive feedback disturbance islanding detection algorithm has the advantages of fast detection speed, little influence on the power quality of grid-connected power, and no blind spot detection. The research results of this paper have certain reference value for microgrid operation control.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM727

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