含分布式电源配电系统中计及警报错误的故障定位

现有针对含分布式电源配电系统的故障定位方法在实际应用时如果存在警报漏报与误报就可能发生误判。针对这一问题,提出了一种综合利用遥信和遥测信息的配电系统故障定位两层模型。首先,利用遥信信息建立故障定位的上层解析模型,然后在此基础上通过遥测数据建立下层模型。所提出的两层模型可以较好地处理含分布式电源配电系统的故障定位,并能给出漏报和误报的警报。最后,采用算例系统说明了所发展的两层模型的基本特征。     

Modeling and analysis of unbalanced distribution system using object-oriented methodology

An object-oriented (OO) model for three-phase unbalanced distribution system is proposed and implemented. Single-phase system components are initially modeled using object-oriented methodology. Later, it is extended to unbalanced three-phase distribution system using the “composition” technique of object-oriented design. The main features of object-oriented methodology such as “inheritance”, “aggregation”, “association” and “polymorphism” have been exploited to obtain a better software model. Three-phase distribution load flow analysis and short circuit analysis modules have been developed using the proposed object model. The performance of the developed software has been tested on IEEE 13-Node, IEEE 34-Node and IEEE 123-Node distribution systems.     

基于IEC61850和Web Services服务的中性点小电阻接地系统接地保护装置的研发

将Web Services通信技术应用于配网自动化领域,有利于降低保护装置接入配电网自动化系统的难度。基于IEC 61850和Web Services服务,研发一款应用于中性点经小电阻接地的配网系统的高性能数字化接地保护装置。分析了中性点经小电阻接地技术在配网中的原理及应用,对中性点经小电阻接地的保护装置进行功能分解和IEC 61850信息建模。采用gSOAP工具开发小电阻接地保护装置的Web Services服务器端;在Windows平台下开发Web Services客户端。最后以GetDataValue服务定时召唤小电阻接地保护装置遥测值为例,验证方案的可行性。     

Modeling and analysis of rural electric distribution feeders

The quality of service provided to rural electric customers can be improved with the accurate modeling and analysis of a distribution feeder. With the use of an analysis program developed for a personal computer, it is possible for an engineer to solve existing feeder voltage profile and loss problems and to plan feeder additions that will improve the quality of service to the customers with reduced losses to the cooperative. The authors describe the accurate model of a distribution feeder and its devices that are incorporated into a radial distribution analysis program (RDAP) developed for the personal computer. An example rural distribution feeder is modeled to demonstrate how the program is used to solve typical design and operational problems     

Active-reactive scheduling of activedistribution system considering interactiveload and battery storage

The increasing penetration of inverter-based distributed generations (DGs) significantly affects the fault characteristics of distribution networks. Fault analysis is a keystone for suitable protection scheme design. This paper presents the modelling methodology for distribution networks with inverter-based DGs and performs fault simulation based on the model. Firstly, a single inverter-based DG model based on the cascaded control structure is developed. Secondly, a simulation model of distribution network with two inverter-based DGs is established. Then, different fault simulations are performed based on the Real Time Digital Simulator (RTDS). Theoretical analyses are conducted to justify the simulation results, including the equivalent circuit of distribution networks with inverter-based DGs and the solution method for loop currents     

配电网CIM综合模型的构建与应用

根据配电网拓扑结构特点和各应用系统对配电网模型的要求,从计算分析和管理需求两方面出发,运用面向对象技术的C IM模型对电力系统资源的通用描述,提出了建立配电网C IM模型的三步建模方法,以完整描述配电网各设备属性和连接关系,从该模型可以得配网计算和设备管理维护所需的信息。最后建立了一个典型馈线系统的C IM标准模型,基于此模型进行了线损计算。     

PCB接触通流能力分析及评估软件开发

介绍了一种基于热电耦合评估PCB温升的方法以及基于仿真与试验结果开发的PCB接触通流评估软件。考虑螺栓连接处的接触电阻,建立了PCB电流传导模型,计算PCB电流密度与发热功率分布;继而建立了考虑传导、对流和辐射的PCB传热模型,计算PCB温度分布。根据仿真结果,分析了PCB铜箔面的温度分布规律及原因,并对比分析了四层铜箔PCB温度随电流和接触端子拧紧力矩变化的规律。同时,开展了相应的PCB接触通流测量试验,仿真与试验结果吻合,验证了计算模型的有效性。最后,开发了相关的PCB接触通流评估软件。     

Supercapacitor Thermal Modeling and Characterization in Transient State for Industrial Applications

A new thermal model, which allows temperature distribution determination inside a supercapacitor cell, is developed. The model is tested for a supercapacitor based on the activated carbon and organic electrolyte technology. In hybrid vehicle applications, supercapacitors are used as energy-storage devices, offering the possibility of providing the peak-power requirement. They are charged and discharged at a high current rate. The problem with this operating mode is the large amount of heat produced in the device which can lead to its destruction. An accurate thermal modeling of the internal temperature is required to design a cooling system for supercapacitor module, meeting the safety and reliability of the power systems. The purpose of this paper is to study the supercapacitor temperature distribution in steady and transient states. A thermal model is developed; it is based on the finite-differential method which allows for the supercapacitor thermal resistance determination. The originality of this paper is in the fact that a thermocouple (type K) was placed inside the supercapacitor from Maxwell Technologies. A test bench is realized. The cases of supercapacitor thermal distribution using natural and forced convection are studied. Simulations and experimental results are reported to validate the proposed model. The results obtained with this model may be used to determine the cooling system required for actual supercapacitor applications.      

含源网荷的智能配电网运行仿真平台研究及应用

考虑配电网存在的源网荷不对称现象、特殊网络结构的基础上,建立了配电网常规元件及分布式电源的稳/暂态模型。针对智能配电网三相不对称的特性,研究了智能配电网相关的三相潮流算法、三相短路电流算法以及三相时域仿真算法。最后,开发了基于OPEN3200系统接口的智能配电网运行仿真平台,并在南京河西新城进行了成功应用,验证了所提方法及研制系统的合理性、有效性。     

兼顾风险与收益的主动配电网非正常停运恢复策略

综合配电网恢复过程中的风险、代价与收益因素对主动配电网的非正常停运恢复策略展开研究。通过评估恢复子过程执行风险和过渡电网运行风险建立配电网恢复风险模型,在此基础上结合电网恢复控制代价和恢复收益建立货币量纲上的多目标优化模型,采用基于贪心策略的启发式算法对配电网恢复问题进行优化求解,并对贪心策略进行了拟无后效性改进。算例仿真表明,所提配电网非正常停运恢复策略能够计及配电网恢复过程中的不确定风险,在保证经济恢复收益最大化前提下最大限度地恢复失电区域的供电,从而提高配电网供电可靠性和恢复过程的经济性。     

综合考虑配电公司及独立发电商利益的分布式电源规划

结合分布式电源接入对配电网的影响,通过对系统网损、电压分布及用户可靠性要求的综合分析确定出了分布式电源候选安装位置解集.为实现分布式电源独立发电商和配电公司的利益均衡,建立了分布式电源单位成本收益和其接入后改善电网所得收益最大化的多目标规划模型,所建模型考虑了分布式电源的投资成本、卖电收益、环境改善,以及网损、电压质量...     

A new optimization model for distribution substation siting, sizing, and timing

This paper presents a new planning optimization model for distribution substation siting, sizing, and timing. The proposed model involves using linear functions to express the total cost function. The developed model includes different electrical constraints such as voltage drops, substation and transformer capacities, power flow, and radial flow constraints. The proposed planning problem is formulated as a Mixed Integer Linear Programming (MILP) problem to avoid the use of nonlinear programming and thus avoiding the possibility of getting trapped in local solutions. A numerical example is presented to validate the effectiveness of the developed model.     

配电网检修计划优化模型设计

从中国配电网的实际情况和配电网设备检修工作的实际需要出发,挖掘和提炼了电网企业最关心的检修计划优化目标以及制定计划中所要考虑的各种影响因素和约束条件,建立了在保证配电网安全运行的前提下,以最大限度提高配电网的供电可靠性、降低设备检修造成的网损为目标的优化模型,并针对该模型探讨了相应的求解方法.     

配电网络故障及继电保护系统动态闭环数字仿真

讨论配电网络故障及继电保护的系统仿真方法.针对配电网络故障仿真的特殊要求和现有仿真方法的不足,重点针对消弧线圈、电流互感器、保护继电器分别建立仿真模块,形成实用的故障暂态仿真模型.基于ATP/EMTP平台,开发仿真软件,实现对故障发生、识别和隔离的动态仿真.仿真结果验证了仿真模型和软件的正确性.该仿真模型为配电网保护系统原理及其暂态性能分析和配电网的故障隔离过程模拟提供了实用的工具.     

Analytical model and algorithm for tracing active power flow based on extended incidence matrix

This paper proposes an analytical model and algorithm for tracing power flow (TPF). The concept, construction approach and properties of extended incidence matrix (EIM) are developed. By using results of an AC or DC power flow solution from any off-line program or state estimation, the extended incidence matrix, generation and load power vectors, and distribution factor matrix are derived so that the analytical model of power transfers between generators and loads can be built. The major advantage of the proposed method is that the matrix theory is used to directly build the TPF model and no proportional sharing assumption on the flow distribution is needed. The method was tested using a 4-bus system, and the IEEE 30-bus and IEEE 14-bus power systems. The case studies indicate that the developed technique can be applied to any power system with or without loop flows.     

基于区间算法和范例学习的配电网网架规划

考虑配电网网架规划中的不确定因素,建立了配电网网架区间规划模型。结合配电网辐射状运行的特点,提出了简单实用的配电网区间潮流计算的端点法。对基于Agent行为和范例学习的遗传算法中的“范例学习”部分进行了修改,使其适应于配电网网架区间规划模型的求解。算例结果表明,提出的算法可以得到鲁棒性强的规划方案。     

Gain clamped erbium-doped fiber amplifiers-modeling and experiment

A spectrum-resolved numerical model for the gain clamped EDFA is developed. Good agreement between the model and experimental results is achieved. The model results reveal the gain, clamped gain spectral distribution and noise figure characteristics of the amplifier. The model is used to optimize the selection of the clamped amplifier laser wavelength and laser output coupling to minimize the noise figure     

基于可靠性及经济性的中压配电网闭环运行方式

介绍了国内外中压配电网闭环运行方式及其特点;综合考虑可靠性及经济性,建立了配电网从开环运行升级为闭环运行的净收益模型,包括一种简化的中压电缆线路可靠性指标,即系统平均停电持续时间(SAIDI)评估模型;探讨了配电网闭环运行适用范围及实施难度。研究表明,国内现有配电网"闭环设计,开环运行"的供电模式限制了供电可靠性的进一步提升。对于经济发达、负荷密度大、有分布式电源接入以及可靠性要求高的地区,在条件允许的情况下,可考虑采用闭环运行方式(主要为来自同一母线的两馈线自环);该运行方式虽然可能增加供电公司的成本,但能够在提升供电可靠性的同时保证良好的社会经济效益。     

电动汽车充电站的最优选址和定容

提出了能够计及地理因素和服务半径的2步筛选法,以此来确定充电站的候选站址。以规划期内充电站的总成本(包括投资、运行和维护成本)和网损费用之和最小为目标,考虑了相关的约束条件,构造了电动汽车充电站最优规划的数学模型,并采用改进的原对偶内点法来求解。修改的IEEE 123节点配电系统算例说明了所发展模型和算法的基本特征。     

通用配电网潮流程序架构设计和实现

针对传统配电网潮流程序用过程式的编程技术开发,存在的可扩充性和可维护性差的问题,采用面向对象的虚继承机制和UML统一建模语言建立了配电网潮流程序的对象模型和动态模型。用VC++ 6.0编制了程序,程序实现了改进的前推回代法和牛顿潮流计算方法,拓扑表示采用树形表示和矩阵表示。并通过实例验证程序,结果表明程序计算速度并无大的差异。程序有好的可扩充性和可维护性。