微电网中分布式光伏发电控制策略研究

发布时间：2018-03-06 02:01

本文选题：微电网　切入点：光伏发电　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,分布式发电以其能就地消化电力,减少集中输电的线路损耗,与大电网供电互为补充,减少电网容量,可以减少对环境的污染等优点受到了广泛关注,尤其是光伏和风力发电得到了快速发展。然而,随着分布式电源接入大电网的数量不断增加,其本身存在的单机接入成本高、对大电网是一个不可控源及并入电网的结构限制等问题也日益凸现出来,这在很大程度上限制了分布式电源的发展。为了协调分布式电源与大电网间的矛盾,充分挖掘分布式发电为电网和用户所带来的价值,美国、欧盟、日本等国相继提出了微电网(Micro grid)的概念。微电网既突破了分布式电源的发展瓶颈,又增强了大电网的末端供电能力。但其改变了系统的结构和性能,使得系统管理趋于复杂化,因此,微电网拥有独特的能量管理系统,光伏电源想要融入其中,必须在发电控制方面与其良好配合。并网运行时,微电网能量管理系统要求光伏电源以电流源形式运行,中央管理器以程序指令方式统筹各个逆变器发送电能,同时要求各逆变器尽量减小输出电能的谐波含量。本文在光伏逆变器并网建模基础上,提出空间矢量脉宽调制定功率控制策略,使光伏逆变器按中央管理器指令定功率发送电能。通过仿真结果和物理实验结果验证了所提控制策略的正确性和有效性。孤岛运行时,由于失去大电网的支撑,母线电压会产生波动。这时,微电网能量管理系统要求光伏电源转变控制策略以电压源形式运行,动态维持微电网内能量平衡,稳定母线电压。本文提出光伏逆变器采用基于主从模式的下垂控制,维持微电网能量平衡,为其它分布式电源运行提供支持,通过仿真和实验验证了所提控制策略的有效性。并网/孤岛切换过程中,如果微电网内旋转负载比例过高,有可能会因为中央管理器孤岛检测时间过长或线路传输延时等情形导致运行状态切换失败。本文提出采用超级电容器和DC/DC斩波电路构成储能装置,给切换过程提供能量支撑,稳定逆变器直流侧电压,通过仿真验证了所提方法的正确性和有效性。
[Abstract]:In recent years, distributed generation with its in situ digestion power, reducing the transmission loss on transmission power, and complement each other, reduce the power capacity, it could reduce the pollution to the environment has attracted extensive attention, especially photovoltaic and wind power generation has been rapid development. However, as the number of distributed power grid increase in the cost of stand-alone access exist in itself, on the grid is not a controlled source and the grid structure limits and other issues are also increasingly prominent, which limits the development of distributed power supply to a great extent. In order to coordinate distributed power and the power system, to fully tap the power of distributed generation and users to bring value to the United States, European Union, Japan and other countries have put forward the micro grid (Micro grid). The concept of micro grid can break through the bottleneck of the development of distributed power supply, and Enhance the power supply capacity of large power grid at the end. But it changed the structure and performance of the system, makes the system management become more complicated. Therefore, the micro grid energy management system has a unique, photovoltaic power to integrate into one, must be in power control and good coordination. And network operation, micro grid energy management system for photovoltaic the power to run the current source, the central manager with overall program instructions of each inverter transmitting electric energy, and the inverter to reduce the harmonic content of the output power. Based on the modeling of photovoltaic grid connected inverter based on space vector PWM is proposed to make the power control strategy of the PV inverter according to the central manager instruction set power transmission power. The simulation results and the experiment results verify the validity and effectiveness of the proposed control strategy. The island operation, due to loss of power Network support, bus voltage will fluctuate. At this time, the micro grid energy management system for photovoltaic power shift control strategy to maintain the dynamic voltage source, micro grid energy balance, stability of bus voltage. This paper proposes the use of master-slave mode PV inverter droop control based on micro grid, maintain energy balance, to provide support for other distributed the power supply operation, through simulation and experimental validation of the effectiveness of the proposed control strategy. The grid / Island switching process, if the micro grid in the rotating load ratio is too high, it may be because the central manager islanding detection time is too long or the transmission delay due to running switch failure. In this paper, using the super capacitor and DC/DC chopper circuit storage device for switching process to provide energy support, stable DC voltage of inverter, the simulation verification of the proposed side The validity and validity of the law.

【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM615

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