微电网运行控制与保护

在新的时代背景下,随着智能化电网的普及和应用,电力体系的稳定性和安全性引起人们的关注,就促使微电网技术应运而生了,进而对电网体系进行完善.基于此,本文主要对微电网运行控制与保护进行了分析.     

微电网技术在主动配电网中的应用探讨

在能源危机日益严重的背景下,电力行业也要采取有效的措施加强节能.要将传统的被动式电网逐渐转变为主动式电网,这样就能够更好地吸纳间歇性的能源.在配电网当中合理地接入微电网技术,最终实现并网运行,能够产生更加智能化与完善的用电网,有效地实现配电网对分布式电源的严格管理与协调,而且能够有效地=节约电网的供电成本,节约能源,保护环境,促进主动配电网的发展.本文分析了在主动配电网当中合理运用微电网技术的方法,希望能够推动电网的良好发展,促进电能服务质量的提升.     

浅析智能电网与新能源

智能电网和微电网是本世纪新兴的两个概念。文中从智能电网与微电网的关系出发,通过阐述中国式智能电网和微电网的内涵,提出未来智能配电网的一种新的组织形式智能微电网,并分析了智能电网与新能源的协调发展。     

微电网的能量协调控制策略研究

近年来,由分布式电源组成的微电网以其高可靠性、可持续性,成为众多学者研究的热点。微电网是一个小型的配电网系统,为分布式电源的接入提供了一种可行方法。微电网有并网和孤岛两种运行状态,并网时可以从大电网获取电能或向大电网提供电能,当大电网出现故障时,微电网能与大电网断开单独运行,微电源和存储设备必须合作才能维持微电网孤岛运行时的能量平衡,因而微电网的协调控制策略一直是一个研究的热点。文中列举并讨论了现有的微电网协调控制策略,对这些不同的控制策略进行比较分析,提出根据微电网不同运行模式和影响因素采取的相应的控制策略。     

基于云计算的智能电网预测与节能技术研究

智能电网中的微电网系统可以为客户提供有效的电力服务,同时微电网的能量交换过程大幅增加了电网系统的能量损耗,针对这一问题,提出一种基于云计算的预测技术,最大限度减少微电网工作过程中的能量浪费与二氧化碳排放,实现绿色的电网通信。同时,为预测技术提出最优策略,进一步降低能耗。实验结果表明,该方案在降低能耗与减少二氧化碳排放方面都表现出显著的有效性,同时还最小化了能量预测过程中的通信传输。     

含多种分布式电源的微电网控制策略研究

微电网是一种可控的小型发电配电系统,是将分布式电源、负荷、储能以及控制装置进行结合,能够对大电网和分布式电源两者之间的矛盾进行有效的解决,从而不断的推动分布式发电技术的发展和进步.但是分布式电源单机接入成本高、控制困难,一定程度上限制了其大规模的使用.为了确保含多种分布式电源的微电网的稳定运行,必须对分布式电源及其相应的电力电子接口设备进行有效的控制.本文结合笔者多年工作经验,阐述了含多种分布式电源的微电网控制策略.     

基于分布式发电的微电网黑启动设计与实现

针对电网故障的不可预测性,基于逆变器控制的基本原理,对锁相环技术以及SPWM技术的数学建模分析,提出多种控制模式下微电网的黑启动控制策略。对分布式电源的控制方法进行了研究,分析比较了微电网控制模式,并将逆变器的控制方法应用到微电网控制中去,在此基础上提出一种新型的恢复速度更快的并行恢复黑启动方案,基于Matlab对其进行了仿真,验证了微电网串行恢复和并行恢复的有效性和可行性。     

微电网继电保护的研究与应用

在我国目前电力行业空前发展的状态下,微电网与智能电网也得到了极大的发展,在电网建设方面都有了广泛的应用,进而也使得人们保护机电的意识逐渐加强,相应的标准也不断得到提升.在继电保护方面,它可以通过环保节能、实用性等特征的运用,达到提高电力系统运作效率的要求.所以,在我国电网建设智能化的过程中,微电网就成为了一个建设研究的方向,制定相关的保护标准或者规定,确保智能电网的稳定安全运行,进而保证国民经济生活顺利进行.     

配网自动化技术在微电网环境下的发展

首先研究分析了现阶段电力工业技术的发展方向,重点阐述了微电网技术与配网自动化技术对于电力系统现代化发展的重要性.然后通过对微电网和配网自动化的定义、控制方式、技术内容的分析,研究总结配网自动化在微电网中的技术地位.同时进一步阐释了微电网技术与配网自动化技术的内在联系,及其相互促进发展的积极作用.最后通过配网自动化在微电网中的应用方向,解释了配网自动化融入微电网技术的必然性.     

多储能直流微电网的分布式控制分析

本文对直流微电网分布式控制的时代意义进行了简要的分析,并围绕直流微电网的内涵以及基本电网的分布式控制结构进行了集中的阐释,也针对两储能直流微电网的稳定性展开讨论。     

High performance communication architecture for smart distribution power grid in developing nations

In a smart distribution power grid, cost efficient and reliable communication architecture plays a crucial role in achieving complete functionality. There are different sets of Quality of Services (QoS) requirements for different data packets transmitting inside the microgrid (a regionally limited smart distribution grid), making it challenging to derive optimal communication architecture. The objective of this research work is to determine the optimal communication technologies for each data packet based on its QoS requirement. In this paper, we have proposed an architecture for a smart distribution power grid with Cyber Physical System enabled microgrids, which accommodate almost all functional requirements of a smart distribution power grid. For easy transition towards optimal communication architecture, we have presented a six-tier communication topology, which is derived from the architecture for a smart distribution power grid. The optimization formulations for each packet structure presented in this paper minimize the overall cost and consider the QoS requirements for each packet. Based on the simulation results, we have made recommendations for optimal communication technologies for each packet and thereby developed a heterogeneous communication architecture for a microgrid.     

不同模式下微电网的能源管理和调度优化

微电网在智慧电网中是非常重要的,确保微电网的最佳和稳定运行是非常必要的.本研究根据微电网并网和孤岛运行模式下的优先级和目标,分别实现了两种优化算法.为了在每种模式下实现最佳运行,该方案降低负载,确定光伏发电水平,并调节储能系统(ESS)的充放电水平.在仿真实验中证明了该调度方法的有效性.并且从实验结果可知,所提出的方案...     

考虑概率区间的微电网短期负荷多目标预测方法

微电网负荷随机性强、波动大,负荷单点预测已经难以满足微电网稳定运行需要.提出一种考虑概率区间的微电网短期负荷多目标预测方法,以循环神经网络为预测模型,以逼近理想解排序策略、网格筛选策略对基本多目标人工蜂群算法进行改进,优化循环神经网络的权值和阈值,避免单目标区间预测中惩罚系数难以选择的问题,对历史负荷数据进行记忆并修正预测结果,有效提高微电网短期负荷区间预测准确性与可靠性.仿真结果表明,本文所构建的考虑概率区间的微电网短期负荷多目标预测方法,预测性能优越、结果准确,可为微电网安全经济调度提供决策依据.     

超导磁场储能型微网的涡流损耗预测控制研究

微网是现代智能电网的精华,具有经济性、环保性与切换灵活性,但存在涡流损耗状况。系统结合超导磁场储能技术实时预测并控制涡流损耗,首先给出预测控制模型,并通过漏磁场和电网导体损耗测算绕组线圈的涡流损耗;研究预测控制拓扑模型,实验波形,电机震荡状态和微网涡流谐波关联。实验结果表明该技术能提升微网供电稳定性,实时预测和控制涡流损耗。内外环调控能在开关频段、边带和倍频周围产生较大的谐波量,减小涡流损耗,保证运转效率与能量。     

直流微网孤岛运行状态电压稳定性分析

直流电压是直流电网运行中重要的状态变量。文章针对由多种微电源及就地负载组成的直流微电网系统,以之作为研究对象,利用阻抗比例判据判别直流微电网电压的稳定性。该方法通过将电源子系统的总输出阻抗对负载子系统的总输入阻抗的比值看作一个等效回路增益,再用 Nyquist稳定性判据分析系统的稳定性。仿真结果表明了直流微电网母线电压稳定性与各参数之间的关系。     

Design of Parallel Inverters for Smooth Mode Transfer Microgrid Applications

In this paper, smooth mode transfers and accurate current sharing are performed in a multi-inverter-based microgrid system by the designed system level controls with control area network communication. Controllers of individual inverters within the microgrid in both grid-tie and islanding modes are also designed to ensure high-quality output waveforms. The mode transfer tests are conducted with an inverter-simulated grid to define the proper transfer procedures. Experimental results show that the inverters can provide stable outputs in different basic microgrid operation modes. With the designed current sharing scheme, the output current is equally shared among paralleled inverters without noticeable circulating current. Both the simulation and experimental results of mode transfer show that the multi-inverter-based microgrid system is able to smoothly switch between the grid-tie and islanding modes to guarantee an uninterrupted power supply to the critical loads within the microgrid.      

A New Topology Pattern for AC-DC Mixed Microgrid

In order to realize the modular design of the microgrid, this paper proposed a new modular topology for the AC-DC mixed microgrid. In that topology, the AC microgrid unit and the DC microgrid unit were packaged together by the back-to-back converter. The battery-supercapacitor hybrid energy storage system was connected to the DC bus of back-to-back converter. By the reasonable design on the battery-supercapacitor hybrid system, the energy storage system could supply the rapid power and energy support for the microgrid spontaneously. The mathematical model and the control algorithm of that microgrid topology were studied. By the simulation analysis, it can be concluded that AC-DC mixed modular microgrid topology could operate steadily on both the grid-connected mode and the isolated mode. Furthermore, we can conclude by the simulation that the designed modular microgrid could operate uninterrupted when the microgrid topology switched from the grid-connected mode to the isolated mode. The seamless switching became the natural property for the modular microgrid. As a result, the modular microgrid topology can be considered as a usual power/load module to realize the friendly power interaction with the power grid.     

网格关键技术论析

信息技术的下一个浪潮高峰是万维网(World Wide Web)升级为网格(Grid)。了解、认识。进而应用网格技术意义重大。网格的关键技术主要有网格硬件、网格操作系统、网格应用层面、网格计算以及其他一些关键技术。     

A grid-interfacing power quality compensator for three-phase three-wire microgrid applications

This paper proposes a grid-interfacing power quality compensator for three-phase three-wire microgrid applications with consideration of both the power quality of the microgrid and the quality of currents flowing between the microgrid and utility system. It is proposed that two inverters connected in shunt and series are used for each distributed generation (DG) system in the microgrid. In each inverter, both positive- and negative-sequence components are controlled to compensate for the effects caused by the unbalanced utility grid voltages. Specifically, the shunt inverter is controlled to ensure balanced voltages within the microgrid and to regulate power dispatches among parallel-connected DG systems, while the series inverter balances the line currents by injecting appropriate voltage components. A current-limiting algorithm is also proposed and integrated within the inverter control schemes to protect the microgrid from large fault currents during utility voltage sags. The proposed compensator has been tested in simulations and experimentally using a laboratory hardware prototype.     

柔性接入微电网的小信号建模

针对传统并网硬开关无法主动调节潮流的问题，利用背靠背变流器取代传统并网硬开关，对配电网与微电网进行柔性互联，便于二者之间的协调控制。为对系统进行稳定性分析，并考虑到不同规模的微网内分布式电源数量的不同，文中建立一种经背靠背变流器接入的含N个分布式电源的微网小信号状态空间模型框架。利用MATLAB对其进行特征值分析，确定了影响微电网稳定性和动态性能的关键参数。在PSCAD/EMTDC平台上搭建出基于下垂控制的微电网柔性并网运行模型，将建立的小信号模型与搭建的仿真模型结合，在多个工况下进行仿真，验证了建模、分析与结论的正确性。