【作者】 苏玲；

【导师】 张建华；

【作者基本信息】 华北电力大学（北京） ， 电力系统及其自动化， 2011， 博士

【摘要】 分布式电源渗透率的增加、政策扶持力度的增大以及国家电网公司实施智能电网的契机,使我国多所研究机构和高校对微网展开了如火如荼的研究工作。微网不仅能解决分布式电源大规模接入的问题,还能发挥各类分布式电源的优势、提高供电可靠性和为用户带来更多的效益。控制是微网实现上述功能的关键技术之一,所以本文对分布式电源控制、微网控制及微网能量管理策略进行了研究,主要工作如下：1.针对逆变型分布式电源控制方式灵活且惯性较小的情况,提出了逆变型分布式电源控制策略。并网运行时为实现分布式电源(微型燃气轮机)“以热定电”的特点,对分布式电源逆变器采取有功电压控制(PV控制)；孤网运行时为实现分布式电源的即插即用,对逆变器采取下垂控制(P-f控制和Q-V控制),在负荷变化时仅利用各分布式电源本地信息进行协调控制分配负荷,并满足负荷对电压和频率的要求。为保证用于改善暂态性能的直流侧储能设备运行安全,在有功下垂控制中,设计增加了功率输出限制环节。应用该控制方法实现了微网并网和孤网运行的灵活切换,并把分布式电源出力限制在允许范围内,保护了直流侧储能设备。2.考虑到网络和负荷实际动态特性以及大容量(兆瓦级)逆变器较小的带宽,为更准确分析微网和大容量逆变器的动态性能,建立了大容量(兆瓦级)逆变型分布式电源微网并网运行和孤网运行时小信号稳定性分析模型,其中包括两个子模型：网络及负荷小信号动态子模型和分布式电源逆变器的小信号动态子模型。通过计算该模型特征值,可直观分析微网小信号稳定性和比较不同控制策略的动态性能；进一步对特征值进行敏感度分析,可为控制器参数和电气参数的优化设计提供依据,从而提高微网小信号稳定性。3.在分析分布式电源与传统电源不同特性的基础上,规划提出了微网能量管理系统的构成、任务和工作流程,能量管理系统还考虑了微网在各种状况和约束下的经济调度和优化运行。针对实验室微网运行控制,提出中央控制器和局部(分布式电源和负荷)控制器相结合的控制策略,该控制策略既能实现微网的灵活运行、无缝切换,又能在孤网运行时跟踪负荷变化,保持系统稳定性。4.基于组态软件iFix对实验室微网监控平台系统进行架构和功能开发,并嵌入了所提出的优化策略和控制策略。该平台为深化微网技术的研究提供了支撑,为相应的教学、实验奠定了基础。更多还原

【Abstract】 Many institutions and universities in our country are working on microgrid in the situation of the increasing penetration of distributed generation(DG), the strong policy support and the implementation of smart grid. Microgrid can not only solve the problem of large scale DG coupling but also play full advantages of DG, improve power supply reliability and bring more benefits to users. Since the key technology of microgrid is control, it is necessary to conduct a comprehensive study on DG control, microgird control and microgrid energy management.The main content of this dissertation are as follows:1.The control of Inverter interfaced DG is flexible and inertialess. DG inverter employs active power and voltage magnitude (PV control) to carry out DG (microturbine) determining power by heat when grid-connected operation. Inverter employs droop control (P-f control and Q-V control) to carry out plug and use when islanding operation. Each DG shares load only according to the local measurement at the situation of load variation and the demands of load for voltage and frequency are met. The minimum and maximum output limits are added in P/f droop control for the safety of energy storage used to improve the dynamic performance. The proposed method can control microgrid flexible switch between grid-connected operation and islanding operation. The output of DG can be limited to its allowable scope and prevent the damage of DC energy storage.2.Ideal inverter model and state-less impedance model of network and loads are currently used to analyze the small signal stability of microgrid, which will cause important dynamics to be omitted. For capturing the dynamics of microgrid and large power inverters more accurately, the complete small-signal model of microgrid based on inverter-interfaced distributed generation is developed when microgrid is gird-connected or islanding. This integrated model consists of two sub-models:the small signal sub-model of network and load considering dynamics and the complete sub-model of DG inverters. The eigenvalues of state matrix of small signal model of microgrid can be used to investigate small signal stability directly and compare the dynamic performance of each contol method. A sensitivity analysis is furtherly implemented which helps to identify the origin of dominate low frequency eigenvalues. This model can optimize parameters and improve the small signal stability of microgrid.3.The functions, tasks and operation flow of energy management system are planned for microgrid after comparing the respective characteristics belong to DG and traditional power. The mathematical formulation on economical dispatching and optimal operation is presented in detail. The control strategy combined central control and local control is put forward for lab microgrid operation and can switch microgrid between grid-connected operation and islanding operation flexibly and seamlessly, follow the load variation and keep system stable.4. Supervisory control platform of lab microgrid is developed using configuration software iFix and embedded with optimal operation and control software. This platform gives the support to have a deep research on microgrid and lays the foundation for teaching and experiment.更多还原