含储能环节的微电网控制策略研究

发布时间：2018-08-06 10:31

【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。分布式电源具有发电方式灵活，对环境友好，能源利用率高等优点，但是分布式电源的大规模渗透会对大电网稳定性产生一些负面影响。微电网不仅能解决分布式电源大规模接入的问题，也能发挥各种分布式电源的优势，提高供电可靠性和效益。微网逆变器作为微网中的基本电力电子接口单元，对其进行合理有效的控制直接关系到微网的安全稳定运行。本文首先介绍了含储能环节的微电网中储能逆变器的控制策略，给出了其控制环路切换方法；然后建立了微电网储能逆变器的数学模型，，对储能逆变器的控制环路进行了参数设计；针对微电网孤岛工作情况下负载不平衡导致的输出电压不平衡，本文首先分析了不平衡产生的根本原因，然后比较了几种负载不平衡控制方法，最终提出了比例积分加谐振的控制方法，实现了孤岛情况下输出电压的平衡控制；微电网并网工作时，系统的稳定性受电网阻抗、微电网逆变器数量和控制器参数等因素的影响，本文采用特征值分析法研究微电网系统的稳定性，并给出了提高微网稳定性的方法；此外，本文在Matlab/Simulink环境下搭建了微网的仿真模型，验证了本文不平衡控制的有效性和稳定性分析的正确性；论文最后根据系统的要求，设计并搭建了一台基于数字控制的100kVA微电网实验平台，给出了微电网储能逆变器的硬件和软件设计过程，并在此平台上完成了微电网孤岛和并网双模式工作和两种模式之间平滑切换的实验，最后给出了实验结果，验证了微电网控制策略的正确性和可行性。
[Abstract]:With the increasingly prominent energy and environmental problems, distributed power generation technology continues to develop. Distributed power generation has the advantages of flexible generation mode, friendly environment, high energy efficiency and so on. However, large-scale penetration of distributed power generation will have some negative effects on the stability of large power grid. Microgrid can not only solve the problem of large-scale access to distributed power, but also play the advantages of various distributed power, and improve the reliability and efficiency of power supply. As the basic power electronic interface unit in the microgrid, the reasonable and effective control of the microgrid inverter is directly related to the safe and stable operation of the microgrid. In this paper, the control strategy of energy storage inverter in microgrid with energy storage link is introduced, and the control loop switching method is given, and then the mathematical model of energy storage inverter in microgrid is established. The parameters of the control loop of the energy storage inverter are designed, and the fundamental cause of the unbalanced output voltage caused by the load imbalance in the isolated island operation of the microgrid is analyzed in this paper. Then, several load imbalance control methods are compared, and the proportional integration plus resonance control method is put forward, which realizes the balanced control of output voltage in isolated island case, and the stability of the system is subjected to the network impedance when the microgrid is connected to the grid. In this paper, the eigenvalue analysis method is used to study the stability of microgrid system, and the method to improve the stability of microgrid system is given. In this paper, the simulation model of microgrid is built in Matlab/Simulink environment, which verifies the validity of the unbalanced control and the correctness of stability analysis. Finally, according to the requirements of the system, A 100kVA microgrid experimental platform based on digital control is designed and built. The hardware and software design process of the microgrid energy storage inverter is presented. The experiments of island isolation and grid-connected operation and smooth switching between the two modes are carried out on this platform. Finally, the experimental results are given to verify the correctness and feasibility of the microgrid control strategy.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM73

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