【作者】 杨文杰；

【导师】 何正友；

【作者基本信息】 西南交通大学 ， 电气系统控制与信息技术， 2010， 硕士

【摘要】 随着能源与环境问题的日益凸显,分布式发电技术不断发展,光伏发电无疑是其中极具代表性和发展前景的一种。然而分布式电源大量接入对大电网带来的诸多不利影响又成为制约其发展的瓶颈,微网技术的出现很好的解决了这一问题。微网作为-个前沿的研究领域,是各国目前研究的热点。考虑到建立微网实验系统的复杂性和局限性,目前常采用软件建立微网动态仿真模型,用以研究分布式电源并网运行、微网运行控制以及智能电网相关问题。因此,建立以光伏发电为代表的分布式电源及微网运行控制仿真模型具有重要的现实意义。本课题以建立微网运行控制仿真平台为目标,在Matlab/Simulink仿真环境中建立了光伏电池以及PQ、V/f、Droop三种典型微网运行控制策略的仿真模型。在分析原理的基础上给出了模型结构和参数设计方法,通过算例验证了模型的有效性和正确性。仿真分析表明所建立的模型可以用于分布式电源并网和接入微网运行控制问题的仿真研究,具有一定的通用性和拓展性。首先,依据光伏电池原理建立了通用的光伏电池工程仿真模型,并采用扰动观察法通过控制Boost电路占空比实现光伏电池的最大功率跟踪控制。仿真表明模型对外界环境变化具有较好的适应性和良好的动态性能。其次,研究实现了光伏发电并网运行控制策略的仿真模型。对于单相光伏发电,建立了电网电压前馈补偿的SPWM电流跟踪控制模型,仿真验证了模型能够实现单位功率因数并网。在三相光伏发电并网的研究中,阐述了PQ控制策略原理并在旋转dq坐标系中建立仿真模型,讨论了软件锁相环结构和电流控制环设计方法。仿真结果表明PQ控制模型实现了有功功率和无功功率的解耦控制。然后,建立了V/f和Droop控制策略的仿真模型。仿真模型可以用于微型燃气轮机、燃料电池、光伏与储能装置结合等分布式电源的运行控制,对微网特别是孤岛运行的控制具有重要意义。通过分析两种控制策略原理,给出了控制结构,建立了仿真模型,研究了模型参数的选择和设计方法。最后,为验证模型有效性和正确性设计了三个微网运行控制仿真算例。通过主从控制算例证明V/f模型能够在孤岛运行中跟踪负荷波动。将Droop模型用于对等控制算例,仿真表明模型满足下垂控制原理,能够实现功率共享并保证频率和电压的稳定。设计了一个综合运用PQ和Droop控制模型的算例,获得了微网在运行模式切换、负荷变化和电源功率变化时的运行特性。仿真结果证明了模型的有效性,表明模型为建立微网运行控制仿真平台提供了有效途径。更多还原

【Abstract】 As the energy and environmental problems become increasingly prominent, the distributed power generation (DG) is undergoing a significant development all around the world. Undoubtedly, the photovoltaic generation (PV) is the most representative DG which has great prospect.However, a large number of accessing to the tradition power grid by DG brought a lot of negative effects and the development of DG is also restricted. Microgrid is the most effective way to make use of DG. As a frontier area of research, Microgrid is the hottest issue which focused by many countries.Considereing the complexity and limitation of establish the Microgrid experimental system, the dynamic simulation model of Microgrid was established in software generally.The simulation model was used for research of DG grid-connected control, Microgrid operation control and also the issue of Smart Grid.Therefore, establish the simulation model of DG which represented by PV and control strategies of Microgrid operation has important practical significance.The purpose of this thesis is to establish the simulation platform of Microgrid operation control, the solar cell model and three typical Microgrid control strategies which consist of PQ, V/f and Droop were established in Matlab separately. Based on the principle of control strategies the model structure and parameter design were given.Effectiveness and correctness of the model was tasted through the simulation example.The result of simulation show that the model can be used in research of DG grid-connected control and DG access to Microgrid operation control. The model has great universal and expansibility.Firstly, Based on the principle of solar cell, a common engineering model is established. Perturbation and Observation method (P&O) is used to control the boost converter to realize the PV Maximum power point tracking (MPPT). The results of simulation show that the method has good adaptability according to external environmental changing and good dynamic performance.Secondly, the simulation model of PV grid-connected operation control strategy was studied. The SPWM current tracking model was used to track the single-phase PV grid-connected control and the grid voltage feed-forward compensation is considered. Simulation shows that the control model can achieve unity power factor.Three-phase PV grid-connected is the key point of this thesis. The PQ control strategy was discussed and control model was established in rotating dq coordinate system. Software phase locked loop (SPLL) and current control loop design was discussed in detail. Simulation proved that the active power and reactive power were decoupled by using PQ control model.Thirdly, the model of V/f control strategy and Droop control strategy were given. This two models used in DG operation control such as Micro-Gas Turbines、fuel cell and combination of PV and energy storage unit. The model of V/f control strategy and Droop control strategy has great significance to Microgrid and island operation specifically. The principles of this two control strategy were analyzed, the model structure designs were given, the models were established in Matlab.The selection and design of model parameters was studied.Lastly, three examples were given for tasted the effectiveness and correctness of the model. Through the Microgrid master-slave operation control example show that the V/f model could follow the changing of load in island operation.The Droop control model was used in Microgrid peer-to-peer operation control control example, the result proved that the modle can adjust the system frequency and voltage automatically, keeping the power balance in isolated operation.An example which PQ and Droop control strategy was comprehensively used was designed. By using this example, the operation variations of the Microgrid, the change of load and the changing of electrical power was imitated and analyzed. Results of simulation proved the effectiveness of the model, show that those modles provided a effective way of eatablishment of simulation platform of Microgrid operation control.更多还原