【作者】 黄涛；

【导师】 马铁东； 韩花丽；

【作者基本信息】 重庆大学 ， 工程硕士（控制工程领域）（专业学位）， 2017， 硕士

【摘要】 近几十年来,能源危机和环境污染问题越来越严重。为了缓解能源危机和环境污染问题,国内外的专家学者提出了以可再生能源为主要发电形式的分布式发电技术。然而,大量分布式电源(Distributed Generators,DG)在连网的同时,也给主电网带来了很多不利的后果。为了减轻分布式电源对大电网的冲击,微电网被人们提了出来。分布式电源的输出电压幅值和输出频率是衡量电能质量的重要指标,只有将其稳定在各自的额定值附近才能保障电力系统安全可靠的运行。在联网运行模式下,微电网系统的电压幅值和频率由主电网提供;一旦进入孤岛运行模式,系统的输出电压幅值和输出频率会发生剧烈波动。为了使电压幅值和频率稳定,研究人员们采取了下垂控制策略,也称为初级控制;然而初级控制下的稳定电压幅值和频率均低于其本身的额定值,为了使系统的输出电压幅值和输出频率恢复到各自的额定值,引入了二级控制。传统的微电网二级控制采用中央控制器的集中控制结构,但这种结构存在很多缺陷,使得系统的可靠性和可扩展性变差,比如通信网络复杂,通信量大,且不具备“即插即用”的功能等。针对以上问题,本文提出了一种分布式协调控制策略,并进行了以下方面的研究:①对微电网的分布式控制结构进行了研究。该结构由三个模块组成,分别是:基于下垂控制的初级控制模块,分布式二级协调控制模块以及分布式经济调度模块。该结构简化了系统的通信网络,减少了通信量,分布式电源可以即插即用,微电网系统的可靠性和扩展性得到了提升。②基于多智能体系统的协调控制理论,针对微电网的二级控制问题,设计了一种分布式协调控制策略。该策略中的控制器只需要每个分布式电源自身的信号和与其直接通信的分布式电源的信号,就能实现DG的输出电压幅值和输出频率的恢复控制;同时实现了分布式电源间输出有功功率和输出无功功率的按比例分配。③设计了一种有限时间下的分布式二级协调控制策略。该算法通过引入分段函数,使得系统中分布式电源的输出电压幅值和输出频率在有限时间内恢复到各自的额定值,同时实现了分布式电源间输出有功功率和输出无功功率在有限时间内的按比例分配。更多还原

【Abstract】 In recent decades,the energy crisis and environmental pollution problems are getting worse.In order to alleviate the energy crisis and environmental pollution problems,domestic and foreign scholars put forward to distributed generation technology which use renewable energy as the main power generation form.However,a large number of distributed generator connect with main grid has brought a lot of adverse consequences.In order to reduce the impact of distributed generator on the power grid,micro-grid was put out.The output voltage amplitude and output frequency of the distributed generator are important indicators to measure the quality of the generator.Only by stabilizing the generator in the vicinity of the rated value can the power system be safe and reliable operation.In the connect network operation mode,the voltage amplitude and frequency of the microgrid system are provided by the main power grid.Once the island operation mode is entered,the output voltage amplitude and output frequency of the system fluctuate violently.In order to stabilize the amplitude and frequency of the voltage,the researchers took the droop control strategy,also known as the primary control;however,the steady-state voltage and frequency under the primary control were all lower than their own ratings.In order to make the system output voltage amplitude and output frequency are restored to their respective ratings,with the introduction of secondary control.The traditional microgrid secondary control adopts the centralized control structure of the central controller,but this structure has many defects,which makes the system reliability and scalability worse.Such as complex communication network,large traffic,and do not have "plug and play" function.In view of the above problems,this paper presents a distributed coordinated control strategy,the following aspects of the study:①The distributed control structure of microgrid is studied.The structure consists of three modules: the primary control module based on the droop control,the distributed secondary coordination control module and the distributed economic dispatching module.The structure simplifies the communication network of the system,reduces the communication traffic,the distributed generator can be plug and play,the reliability and expansibility of the microgrid system has been improved.②Based on t he coordinated control theory of multi-agent system,a distributed coordinated control strategy is designed for the secondary control problem of microgrid.The controller in this strategy only needs the signal of each distributed generator itself and the distributed generator signal which communicates directly with it,can realize the output voltage amplitude and output frequency recovery control of DG.At the same time,the distributed generator output active power and output reactive power in proportion.③Design a distributed second-order coordinated control strategy with finite time.By introducing the segmentation function,the output voltage amplitude and output frequency of the distributed generator in the system are restored to their respective rated values in finite time,and achieve output active power and output reactive power of distributed generator proportional distribution in finite time.更多还原