分布式光伏发电系统对电网的影响与对策

文中介绍了分布式光伏发电的特性,分析了分布式光伏发电的接入对配电网电压、保护以及电网规划等方面的影响,并提出构建含有分布式光伏发电接入电网的运行、监测和控制设备的解决对策,为大量分布式光伏发电系统接入电网提供一定的理论技术支持。     

微网技术在解决分布式电源并网问题中的应用分析

分布式发电技术,其发电方式灵活,投资成本较低,与周边环境兼容性较好,将分布式电能接入到电网中,可以提高电网供电可靠性。然而分布式电源并网技术也会对电网电压及电能质量带来较多问题。引入微网技术,可以有效解决分布式电源并网问题。在概述微网技术概念及应用优势的基础上,重点对微网技术在毹决分布式电源并网问题中的应用进行探索。实践证明,微网技术,能够有效解决分布式电源并网过程中对电网所带来的电压及电能质量问题。     

分布式能源接入对配电网的影响

随着电网规模的日益扩大,重点研究了分布式电源接入后对电网运行的影响.主要从网损、电能质量、继电保护系统、电网规划以及电网可靠性六个方面阐述了影响的结果,为后续分布式电源接入电网工作的开展提供了参考.     

基于FFT的双向电能计量算法及仿真研究

双向电能计量要求在满足传统意义的负荷侧接入电网并就近给负荷供电的条件下,能够准确地计量电能并解决大量分布式发电接入电网时产生的谐波污染、电能流向等问题。通过对双向电能计量基本原理的研究,利用四象限功率测量原理,判别电流的流动方向。对基于FFT的双向电能计量算法进行分析,总结变换序列的物理意义,并进行仿真验证。研究表明:采用变换序列前半部分功率计算公式可以明显减少计算量,并能够通过其具体的物理含义判断功率的运行状态,实现了单独计量基波与谐波电能。     

新能源分布式发电并网对整个电网的影响分析

实现就地能源的开发与利用,减少远距离输电的损耗,一种高效、环保、灵活的新型发电技术——分布式发电(Distributed Generation,DG)成为智能电网中一项重要的组成部分,很快成为电力系统新的研究热点。目前,对分布式电源的研究已经取得了突破性进展,并且在电能生产中所占比重不断增加。分布式电源的广泛应用将对传统的电力系统产生极大的影响,包括配电网的电能质量、系统可靠性、继电保护等方面。通过研究分布式电源对配电网电能质量的影响将更好的指导我们如何充分发挥分布式电源的优势。     

分布式光伏对户用配电网电能质量影响研究

随着高密度分布式光伏(PV)接入大电网系统,局部电网需要额外承担这类电源系统带来的一系列电能质量影响问题,采用基于光伏电池实际物理特性建立的组件模型,结合逆变器拓扑结构和控制模型,通过MATLAB/Simulink仿真平台,搭建三相分布式光伏接入户用配电网的仿真模型。仿真研究了高密度分布式光伏对户用配电网的电压、谐波等电能质量影响。通过搭建0.4 kV配电馈线模型,仿真研究了高密度分布式光伏接入0.4 kV配电网络的接入场景分布、辐照强度波动、不同接入容量、位置和数量等情况下,配电馈线各节点电压质量分布的影响规律,得到相关分析结论,提出平抑分布式光伏影响的改善措施。     

分布式发电对配电网的影响及规划方法

本文介绍了分布式发电的特性,分析了分布式发电的接入对配电网经济安全性、运行效益、继电保护、电压波动等方面的影响,并提出基于分布式电源接入容量和拓扑分布式发电的规划方法,为本地区的大量分布式发电系统接入配电网提供一定的理论技术支持。     

分布式发电并网系统综述

随着分布式发电(Distributed Generation)应用的增加,越来越多的分布式发电正在接入电网,由此带来的并网问题日益重要:并网系统(包括硬件和软件)主要用来连接分布式发电和电网(通常是本地电网),本文主要讨论了分布式发电与电网之间的并网类型,并网系统的分类、功能、主要结构及采取的控制方法,并简要介绍了现有的分布式发电并网导则。     

储能技术在光伏并网系统中的应用研究

随着光伏发电在电力系统的不断渗透,给配电网带来的电能问题愈发突出,储能技术的应用对改善光伏并网系统的电能问题有重大作用.本文分析了光伏发电接入给配电网带来的电压及其调整、电能质量、电网保护等电能影响,总结了目前电力系统中机械、电磁、电化学等典型储能技术的发展与应用现状,深入研究了储能技术的应用对改善光伏并网系统中电力调峰、电能质量、断电保护等问题的重要作用.     

一种分布式发电功率时间序列波动性量化评估方法

未来智能电网将接纳越来越多的分布式能源,而分布式能源的广泛接入具有提高系统的能源效率、经济性、韧性以及可持续性的潜力。然而,以风力发电和光伏发电为主的分布式能源由于其固有的波动特性,在大规模接入电网时会给系统带来诸多问题。因此,定量刻画分布式发电功率的波动性对于现代电力系统而言至关重要。基于此,该文借助时间窗、包络线和勒贝格积分,通过提取分布式发电功率中高频信息和变化趋势的波动性特征,定义了量化分布式发电功率波动性的指标——波动率。通过检验风电功率时间序列的波动性、验证平滑效应以及与预测误差和已有指标进行对比分析,验证了所提出的波动率在衡量分布式发电功率波动性的有效性。     

分布式发电接入配网系统的规划方法及配套技术探讨

分布式发电网络是现阶段对于电力资源有效利用,提高我国电网电力供应能力的重要基础.针对配网系统的特点,提出有效的解决方案,制定科学合理的规划,是分布式发电接入配网系统的重要前提.相关配套技术也是保证分布式发电接入配网系统顺利进行的有效保证,是未来电网的发展方向.文章对此进行了分析和探讨,以期为我国分布式发电技术的发展提供一定的实践经验.     

Distributed control of renewable generation units with integrated active filter

Due to the current concern about the environment, there is a growing interest in distributed generation from renewable energy sources. Usually a power electronic converter is required to interface renewable generation units with the utility grid. The power electronic converters can be designed to provide nonactive power in addition to active power supply in order to compensate distorted currents. This paper proposes a distributed control method for converter-interfaced renewable generation units with active filtering capability. Agent-based communication makes coordination between the generation units possible. Experimental results are included to demonstrate the validity of the proposed method.     

Modeling the maximum power output of a distributed PV fleet

In areas with a high (photovoltaic) PV penetration, the installed PV capacity is the decisive factor in network planning. This article discusses meteorological impacts on distribution networks in these areas. The focus thereby is to determine the maximum feed‐in power of a distributed PV fleet. Therefore, a meteorological classification of the situations with maximum feed‐in is presented. With these results, the maximum feed‐in power is calculated for Germany. The maximum feed‐in of a distributed PV fleet is found for clear sky situations with a limit of 85% of the installed standard test condition power. This limit could be confirmed by the analysis of measured PV power feed‐in and its impact on the voltage levels in a distribution grid. The investigations are based on the analysis of data from a very detailed measurement campaign in a distribution grid with very high PV penetration in southern Germany. Copyright © 2014 John Wiley & Sons, Ltd.     

Distributed power generation versus grid extension: an assessment of solar photovoltaics for rural electrification in Northern Ghana

The competitiveness of distributed solar photovoltaic (PV) power generation for rural electrification in northern Ghana is assessed and compared with the conventional option of extending the national grid and increasing the capacity for centralised power generation. A model is constructed to calculate the life‐cycle cost (LCC) of the two options and to test the sensitivity of different parameters. All calculations are based on information from the GEF/UNDP pilot region in the East Mamprusi District. In addition to the economic aspect, issues of quality and environmental effects are discussed. The LCC of distributed PV is lower than that of a grid extension for an electricity demand corresponding to solar home systems of 140 W_p or smaller. Thus, distributed PV is cost competitive for purposes of lighting, entertainment, information and basic public facilities, such as schools and hospitals. The LCC for the option of grid extension with central power generation is dominated by the cost of low‐voltage micro‐grids within the communities. Important factors are the density of households and the penetration (fraction of households electrified), as they affect the line length per connected household. The relatively low cost of regional medium‐voltage grids makes the geographical location of each community less important than expected. Battery replacement every fifth year makes up the major part of the LCC of solar home systems and is also responsible for the large energy input in the production of the systems. This could limit both future cost reductions of distributed PV and its potential to mitigate greenhouse gas emissions. Copyright © 2002 John Wiley & Sons, Ltd.     

分布式并网发电系统孤岛检测方法综述

分布式发电系统并网运行时处于孤岛状态会对设备造成损坏,影响电力系统安全正常运行,严重时甚至可能会威肋到线路检修人员的人身安全.因此,对分布式发电系统孤岛检测方法的研究具有现实意义.本文综述了分布式并网发电系统孤岛检测的基本方法,并对其进行分类,最后对该领域的研究方向作出了展望.     

Enhancement of Distributed Generation by Using Custom Power Device

Wind energy (WE) has become immensely popular for distributed generation (DG). This case presents the monitoring, modeling, control, and analysis of the two-level three-phase WE based DG system where the electric grid interfacing custom power device (CPD) is controlled to perform the smart exchanging of electric power as per the Indian grid code. WE is connected to DC link of CPD for the grid integration purpose. The CPD based distributed static compensator, i.e. the distributed static synchronous compensator (DSTATCOM), is utilized for injecting the wind power to the point of common coupling (PCC) and also acts against the reactive power demand. The novel indirect current control scheme of DSTATCOM regulates the power import and export between the WE and the electric grid system. It also acts as a compensator and performs both the key features simultaneously. Hence, the penetration of additional generated WE power to the grid is increased by 20% to 25%. The burden of reactive power compensation from grid is reduced by DSTATCOM. The modeling and simulation are done in MATLAB. The results are validated and verified.     

Interaction between photovoltaic distributed generation and electricity networks

Electricity power systems worldwide have traditionally been designed to a vertically connected scheme characterised by centralised generation. Over the last few decades, several factors have dictated a gradual shift from the central‐control approach to a more distributed layout where distributed generation (DG) technologies are effectively integrated and not just connected (appended) to the networks; amongst others liberalisation of electricity markets, security and quality of supply and environmental issues. Photovoltaic powered distributed generation (PV‐DG), although still having a much lesser impact than other DG technologies, is increasingly being embedded into electricity distribution networks worldwide within the framework of successful regulatory state and marketing programmes. PV‐DG has added values (benefits) for the electricity systems that extend from peak power and load reduction (when deployed close to electricity consumption points) to participation in grid‐supporting or grid‐forming modes of operation. The question arises as to what the present situation of PV technology is for its optimal integration in distribution networks, whether there are still technical barriers to overcome as well as new opportunities for PV in future renewably supplied electricity systems. This paper presents the current state of knowledge concerning these topics from a European perspective with regard to different grid structures. It also discusses existing standards, new opportunities to provide grid services and research and development needs identified to fully exploit the added‐value—and still developing—benefits of PV‐DG. Copyright © 2008 John Wiley & Sons, Ltd.     

微电网技术应用分析

目前,微电网技术已成为智能化电网建设中最关键的技术之一.该技术在我国的发展受智能电网能源需求的影响深远,且与分布式发电技术密切相连.文章对微电网关键性技术及其应用进行了研究.     

Integration von Energiemarkt und Verteilnetzbetrieb durch einen Flexibility Operator

The growing share of volatile distributed generation in the electric power grids results in increased local network utilisation and challenges the conventional strategies for maintaining the system balance. While grid extensions and smart grid solutions are considered for network utilisation issues, new market mechanisms are in focus for the balancing challenge. It can be expected that distributed generators on one hand will be able to supply only part of their available power to the grid in peak times, and on the other hand will have (potentially changing) contracts with different trans-regional virtual power plants. Against this background it will be necessary to define rules dealing with expected network access conflicts. One strategy also followed in this work is to find market mechanisms that support economically efficient network extension. Such mechanisms will have to include local flexibility markets that allow for compensating network bottlenecks. This work proposes strategies and technical interfaces for coordinating market and grid operation by means of a “Flexibility Operator”. Its integration into a holistic smart grid concept is discussed.