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1.
《International Journal of Electrical Power & Energy Systems》2013,44(1):868-879
With the increased installation of renewable energy based distributed generations (DGs) in distribution systems, it brings about a change in the fault current level of the system and causes many problems in the current protection system. Hence, effective protection schemes are required to ensure safe and selective protection relay coordination in the power distribution system with DG units. In this paper, a novel adaptive protection scheme is proposed by integrating fault location with protection relay coordination strategies. An automated fault location method is developed using a two stage radial basis function neural network (RBFNN) in which the first RBFNN determines the fault distance from each source while the second RBFNN identifies the exact faulty line. After identifying the exact faulty line, then protection relay coordination is implemented. A new protection coordination strategy using the backtracking algorithm is proposed in which it considers the main protection algorithm to coordinate the operating states of relays so as to isolate the faulty line. Then a backup protection algorithm is considered to complete the protection coordination scheme for isolating the malfunction relays of the main protection system. Several case studies have been used to validate the accuracy of the proposed adaptive protection schemes. The results illustrate that the adaptive protection scheme is able to accurately identify faulty line and coordinate the relays in a power distribution system with DG units. The developed adaptive protection scheme is useful for assisting power engineers in performing service restoration quickly so as to decrease the total down time during faults. 相似文献
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基于故障相关区域自适应划分的分布式保护新原理 总被引:3,自引:1,他引:2
分布式发电(DG)条件下的配电网潮流流向发生了很大变化,传统的配电网保护原理已不再适用于DG系统。结合多DG接入下的配电网部分母线节点可以通过电流量来判断故障方向的特点,提出了一种具有较强自适应性的故障相关区域划分方法,而这种分布式的、缩小上传保护电流数据范围的算法减少了保护数据在信道上排队避让的时间,保护装置只需得到故障相关区域内的故障电流数据即可正确动作,实现了保护的选择性及速动性,降低了对通信系统的依赖性。将IEC61850应用在DG系统的继电保护中,可以解决DG的保护与控制系统中的异构性和保护数据异步传输的问题。最后通过实验验证了该算法的快速性。 相似文献
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分布式电源大量接入配电网,改变了传统配电网单侧电源结构,易导致配网线路中出现双向潮流、电压越限和潮流波动等问题.文章首先分析了基于恒定功率控制的逆变型分布式电源故障特性以及有源配电网故障特性,提出了具有自适应幅值比的有源配电网差动保护方案.利用端电流的相位差自适应调整保护方案的幅值约束条件:在区内发生故障时,可以减少制动范围,防止保护拒动;在区外发生故障时,则可以增加制动范围,防止保护误动.最后,在PSCAD中搭建相关仿真模型,对所提有源配电网保护方案进行验证,结果表明该保护方案具有良好的适应性. 相似文献
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当直流系统的母线发生故障时,故障电流迅速上升,目前直流配电网母线保护基本引用了交流保护方案,动作时间较长,不利于直流故障的快速隔离。为保证经济性的同时,实现在直流配电系统母线故障时的可靠快速保护,首先对直流配电网母线故障特性进行分析,然后对直流配电网母线保护接线方案、保护算法、资源配置进行改进,提出了差流直接通过直流互感器采集、采用电流变化率算法、分级处理数据、使用不同形态出口继电器等方法。通过实时数字仿真仪进行仿真分析,验证了所提方法的有效性,该方法在兼顾经济性同时可以有效提高直流配电系统母线保护的可靠性和快速性。 相似文献
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刘翊平 《电力系统保护与控制》2017,45(18):163-169
在城区配电网络中,为了缩小施工停电范围,方便调度,环网柜、分段断路器设置多,且间隔距离小。传统继电保护很难满足选择性要求,采用重合器因多次重合对系统冲击大,亦不太合适。通过分析老装置存在的不足,充分利用传统分布式保护的优点,结合基于集中信息智能馈线自动化原理,提出了一种新的故障处理恢复策略。该方案结合两者的优点,借鉴保护原理,使装置通信量小、开关动作次数少,能有效精确定位故障点,实现最小范围自动隔离故障,解决配网自动化实际应用中可能遇到的一些疑难问题,满足了智能化要求。 相似文献
10.
Adaptive overcurrent protection scheme coordination in presence of distributed generation using radial basis neural network
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Uma Uzubi Um Daniel Nmadu Nnaemeka Ugwuanyi Ogah Ekechi Ogah Ngozi Eli‑Chukwu Marcellinus Eheduru Arthur Ekwue 《电力系统保护与控制》2023,8(4):1046-1064
The operational performance of conventional overcurrent protection relay coordination connected to a distribution network is adversely afected by the penetration of distributed generators (DG) at diferent buses in the network. To address this problem, this paper proposes a novel adaptive protection coordination scheme using a radial basis function neural network (RBFNN), which automatically adjusts the overcurrent relay settings, i.e., time setting multiplier (TSM) and plug setting multiplier (PSM) based on the penetration of DGs. Short circuit currents and voltages measured at diferent buses are acquired using the remote terminal units (RTU) connected to diferent buses within the terminal network. Communication between the various remotes and local end station RTUs is through hybrid communication systems of fber optic and power line communication system modules. The new adaptive overcurrent protection scheme is applied to the IEEE 33-bus distribution network with and without DGs, for single and multi-DG penetration using both the ETAP and MATLAB software. The simulation results show the proposed scheme signifcantly improves the protection coordination. 相似文献
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针对分布式光伏电源接入配电网使得传统配电网继电保护存在可靠性、灵敏性降低的问题,提出了一种考虑母线多分支情况下应用偏度系数来衡量暂态零序电流极性的分布式故障定位方法。分析了分布式电源接入的配电网发生单相接地故障时零序电流的分布特征,发现故障时刻故障区段两端暂态零序电流极性相同,非故障区段两端暂态零序电流极性相反,引入偏度系数来衡量暂态零序电流的极性,实现分布式故障定位。仿真结果表明,该方法能够适用于含分布式光伏电源配电网的故障定位,且在不同的故障条件下具有较强的适用性。 相似文献
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Optimal operation modes of photovoltaicbatteryenergy storage system basedpower plants considering typical scenarios
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Yajing Gao Fushen Xue Wenhai Yang Qiang Yang Yongjian Sun Yanping Sun Haifeng Liang Peng Li 《电力系统保护与控制》2017,2(4):397-406
Emission of greenhouse gases and depletion of fossil fuel reserves are two key drivers, which are forcing the
mankind to generate the future energy demand from the renewable energy resources. These resources are
generally distributed in nature and are directly integrated at distribution levels. Increasing penetration of the
distributed energy resources in distribution power networks creates additional operational and control issues.
These are mostly regulatory, economical load dispatching, power quality and protection issues.
Generally power distribution systems are protected with the help of dedicated over current based protection
schemes. But increasing share of distributed energy resources penetration in electric utilities poses a serious
threat to the existing protection coordination schemes of the distribution systems. Distributed energy resources
connected distribution networks become interconnected in nature and protection coordination schemes, which are
designed for unidirectional flow of fault currents become ineffective/non-functional.
Therefore, new protection coordination schemes are required for providing the adequate protection coordination for
distributed energy resources connected electric power networks. In the available literature, the protection coordination
schemes for radial distribution systems and developments in the area of protection coordination are discussed in
detail. A thorough review for all these protection coordination schemes for distribution systems with and without
distributed energy resources is done in this review article. It includes the analytical and artificial intelligence based
techniques application for coordination of protective relays in the distribution systems. The limitations and research
gaps in the area of protection coordination schemes are also presented in this review article.
The aim of this research paper is to bring all the available research in the area of relay coordination on one platform, so
that it will help the emerging researcher to identify the future scope of relay coordination application for distributed
energy resources connected distribution systems. 相似文献
14.
Adaptive relay co-ordination using a busbar splitting approach for a system integrity protection scheme
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Power system faults can often result in excessively high currents. If sustained for a long time, such high currents can damage system equipment. Thus, it is desirable to operate the relays in the minimum possible time. In this paper, a busbar splitting approach is used for adaptive relay setting and co-ordination purposes for a system integrity protection scheme (SIPS). Whenever a fault occurs, the busbar splitting scheme splits a bus to convert a loop into a radial structure. The splitting schemes are chosen such that the net fault current is also reduced. Busbar splitting eliminates the dependency upon minimum breakpoints set (MBPS) and reduces the relay operating time, thus making it adaptive. The proposed methodology is incorporated into the IEEE 14-bus and IEEE 30-bus systems with single and multiple fault conditions. The modeling and simulation carried out in ETAP, and the results of the proposed busbar splitting-based relay co-ordination are compared with the MBPS splitting-based relay co-ordination. 相似文献
15.
Emission of greenhouse gases and depletion of fossil fuel reserves are two key drivers, which are forcing the
mankind to generate the future energy demand from the renewable energy resources. These resources are
generally distributed in nature and are directly integrated at distribution levels. Increasing penetration of the
distributed energy resources in distribution power networks creates additional operational and control issues.
These are mostly regulatory, economical load dispatching, power quality and protection issues.
Generally power distribution systems are protected with the help of dedicated over current based protection
schemes. But increasing share of distributed energy resources penetration in electric utilities poses a serious
threat to the existing protection coordination schemes of the distribution systems. Distributed energy resources
connected distribution networks become interconnected in nature and protection coordination schemes, which are
designed for unidirectional flow of fault currents become ineffective/non-functional.
Therefore, new protection coordination schemes are required for providing the adequate protection coordination for
distributed energy resources connected electric power networks. In the available literature, the protection coordination
schemes for radial distribution systems and developments in the area of protection coordination are discussed in
detail. A thorough review for all these protection coordination schemes for distribution systems with and without
distributed energy resources is done in this review article. It includes the analytical and artificial intelligence based
techniques application for coordination of protective relays in the distribution systems. The limitations and research
gaps in the area of protection coordination schemes are also presented in this review article.
The aim of this research paper is to bring all the available research in the area of relay coordination on one platform, so
that it will help the emerging researcher to identify the future scope of relay coordination application for distributed
energy resources connected distribution systems. 相似文献
16.
由于含有多种具有互补特性的分布式电源,多能互补微电网在能源综合利用、供电可靠性和运行经济性方面具有明显的优势。然而与传统配电网相比,各类分布式电源的并入导致微电网拓扑结构和运行方式变得更为复杂,并网和离网运行对应的故障特性存在差异,使得传统继电保护方案难以满足此类微电网保护的要求。针对这一问题,首先围绕传统继电保方案的不足展开讨论,分析微电网网内故障特点,继而提出一种适用于微电网的改进故障辨识算法,以实现对网内故障的快速准确辨识。综合考虑多能互补微网继电保护的需求,结合改进故障辨识算法,将改进电流差动保护与广域自适应电流速断保护相结合,提出一种适用于微电网分布式电源上下游线路的综合继电保护算法,在缩小故障影响范围的基础上,提高保护响应速度并降低保护拒动的概率。最后,利用RT-LAB实时仿真系统构建含风、光、储、微型燃气轮机等分布式电源在内的多能互补微网模型,通过网内模拟不同类型故障,验证了所提故障辨识和继电保算法的有效性。 相似文献
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对国内外风电接入后对电网继电保护的影响问题进行了综述。分析了不同类型风电机组的故障特征、短路电流特性以及影响风电场短路电流的因素。分别论述了风电接入对送出变压器、送出线路以及配电网继电保护的影响。基于风电接入系统继电保护的性能,总结了风电接入系统继电保护存在的不协调问题及相应的解决方案。建议后续研究应基于风电场的低电压穿越特性加强风电系统故障特性研究,重视风电场自动控制系统和电网继电保护与安全自动装置的配合,研究机组保护与风电场保护、系统保护之间的协调配合,全面解决风电系统继电保护面临的问题。 相似文献
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This paper presents a day-ahead optimal energy management strategy for economic operation of industrial microgrids
with high-penetration renewables under both isolated and grid-connected operation modes. The approach is based on a
regrouping particle swarm optimization (RegPSO) formulated over a day-ahead scheduling horizon with one hour time
step, taking into account forecasted renewable energy generations and electrical load demands. Besides satisfying its local
energy demands, the microgrid considered in this paper (a real industrial microgrid, “Goldwind Smart Microgrid System”
in Beijing, China), participates in energy trading with the main grid; it can either sell power to the main grid or buy from
the main grid. Performance objectives include minimization of fuel cost, operation and maintenance costs and energy
purchasing expenses from the main grid, and maximization of financial profit from energy selling revenues to the main
grid. Simulation results demonstrate the effectiveness of various aspects of the proposed strategy in different scenarios. To
validate the performance of the proposed strategy, obtained results are compared to a genetic algorithm (GA) based
reference energy management approach and confirmed that the RegPSO based strategy was able to find a global
optimal solution in considerably less computation time than the GA based reference approach. 相似文献
19.
A new coordinated backup protectionscheme for distribution network containingdistributed generation
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This paper proposes a new backup protection scheme, named coordinated backup protection (CBP) scheme, for
distribution networks containing distributed generation. The proposed protection scheme takes into account the
issues faced by traditional backup protection, such as difficulty in setting parameters and complex cooperation,
and considers the features of distribution networks, such as changeable power flow because of high penetration
of distributed generation sources and insufficient measuring quantities. The CBP scheme includes two aspects:
coordinated substation protection and regional master substation protection, who also work as nearby backup
protection and remote backup protection respectively. The two protections support each other by local information
coordination and regional information sharing, in order to improve the reliability of fault identification. The configuration
principles and performances of the proposed backup protection scheme are addressed in the paper. Different fault
conditions in the IEEE 14-node system have been used to illustrate and verify the feasibility of the CBP scheme 相似文献
20.
Fault identification scheme for protection and adaptive reclosing in a hybrid multi-terminal HVDC system
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A fault identification scheme for protection and adaptive reclosing is proposed for a hybrid multi-terminal HVDC system to increase the reliability of fault isolation and reclosing. By analyzing the "zero passing" characteristic of current at the local end during the converter capacitor discharge stage, the fault identification scheme is proposed. The distributed parameter-based fault location equation, which incorporates fault distance and fault impedance, is developed with the injection signal and the distributed parameter model during the adaptive reclosing stage. The fault distance is determined using a trust region reflection algorithm to identify the permanent fault, and a fault identification scheme for adaptive reclosing is developed. Simulation results show that the proposed scheme is suitable for long-distance transmission lines with strong anti-fault impedance and anti-interference performance. Also, it is less affected by communication delay and DC boundary strength than existing methods. 相似文献