光伏发电系统电气设备故障原因及处理措施分析

随着中国光伏发电装机规模的不断扩大，光伏发电量逐年增加，能源结构持续优化，但各光伏电站的运行质量参差不齐，光伏发电系统中电气设备的运行质量和故障处理效率直接影响了光伏电站的发电效率、平准化度电成本及电网安全稳定运行。总结了光伏发电系统中光伏组件、汇流箱、逆变器在运行过程中常出现的故障问题，分析了产生故障的原因，并提出处理或预防故障的措施，旨在提高光伏电站安全稳定运行质量，保障光伏电站经济效益。     

船舶发电柴油机缸套穴蚀的原因分析与探讨

介绍某轮船舶发电柴油机缸套穴蚀的故障现象及故障处理过程,结合柴油机缸套穴蚀的机理,对该轮发电柴油机缸套穴蚀故障的原因进行了探讨与分析。分析表明:发电柴油机管理不当、维护保养不良是造成此次缸套穴蚀的主要原因。据此提出了加强对发电柴油机日常维护管理的措施。     

船舶发电柴油机增压器喘振故障分析

船舶发电柴油机增压器喘振故障分析陈宝凤１引言在轮机管理工作中．往往会遇到各种各样的故障．对于通常情况下的故障应该说并不难排除，然而有些故障．即非常规性故障排除２来则颇费周折。本文以一起船舶发电荣油机增压器喘振故障为例．介绍对此故障的分析思路与排除方法...     

分布式发电对配电网继电保护的影响

分布式发电是一种新兴的高效、环保的发电技术,近年来获得飞速发展。然而,大量分布式发电系统的接入改变了配电网的故障电流大小和分布以及原有继电保护装置的基础条件,对配电网的继电保护造成影响。分析了分布式发电接入对馈线的两段式保护和自动重合闸以及分支线的熔断器保护产生的各种可能影响,对分布式发电的广泛推广具有一定的意义。     

光伏发电系统建模及运行特性仿真研究

随着并网光伏发电装机规模的快速扩张,光伏发电大规模接入电网后运行特性的分析研究已成为当下光伏发电相关核心课题之一,而光伏发电系统建模是理论课题研究最为关键的一个环节。文章结合目前国内大中型光伏电站关键部件应用现状建立了光伏发电系统仿真模型,基于PSASP软件仿真分析了光伏发电的正常运行和故障运行特性,同时验证了模型的有效性。     

太阳能光伏发电系统直流保护探讨

针对太阳能光伏发电系统的直流部分,根据近年来常见的一些故障现象及其发生的原因,提出一些保护方法及改进措施,以促使光伏发电技术的进步,并促进太阳能光伏产业的持续发展。     

分布式光伏发电系统直流故障电弧保护装置测试和评估技术的研究与探讨

针对分布式光伏发电系统直流故障电弧发生的原理、常见评价手段及功能检测评估方法等方面进行了综合论述,为分布式光伏发电系统直流故障电弧保护装置的测试和评估提供了一些建议。     

暂态干扰下并网光伏发电系统故障特性研究

基于Matlab/Simulink软件建立了光伏发电系统的仿真模型，在此模型上分别模拟了电源侧扰动和电网侧扰动，通过分析扰动下光伏系统输出特性的变化情况，研究了暂态干扰下光伏发电系统的故障特性。     

DF4型机车固定发电控制电路的改进

针对几起DF4型机车在稳态运行时突变为固定发电模式,造成多个电器及保护装置烧损,通过分析、论证,对原有固定发电电路进行了改进,有效消除了此类故障。     

分布式发电条件下配电网故障定位的矩阵算法

分布式发电(DG)接入配电网后,配电网变成了多电源复杂网络,传统的故障定位算法不再适用.本文提出了一种能解决多电源复杂配电网多重故障定位(可含有馈线末端故障)的矩阵算法.该算法对于故障信息不完备和故障信息畸变的情况同样适用.算例测试结果验证了该方法的正确性和可行性,在配电网实时故障定位的应用中具有很大的潜力.     

Parameter optimization of the biohydrogen real time power generating system using differential evolution algorithm

By comparing the differential evolution and genetic algorithms, this study attempts to optimize estimation of a biohydrogen real time power generating system in which circuit parameters fluctuate with operating temperature and current density. Based on uses of the differential evolution algorithm method, optimal estimation of the circuit parameters is achieved by data from a V–I characteristic experiment on the proposed biohydrogen real time power generating system. The circuit feature is then solved by formulating the estimated circuit parameters based on Kirchhoff’s law to elucidate its feature of the biohydrogen real time power generating system and results show that DE is faster than GA and more accurate. Next, the estimated V–I characteristics are compared with measurement results to demonstrate the feasibility of the proposed method.     

Optimizing circuit parameters of the biohydrogen real-time power generating system by genetic algorithm

This study performs optimal estimation of circuit parameters for a biohydrogen real-time power generating system by using a penalty-function genetic algorithm (GA). Circuit parameters of this system change with operating temperature and current density; some circuit parameters are nonlinear. To elucidate the circuit characteristics of the whole system, this study uses penalty-function GA to optimally estimate circuit parameters using data from a V–I$V–I$ characteristic experiment on novel biohydrogen real-time power generating system. This study then solves the circuit characteristic by the estimated circuit parameters formulated utilizing Kirchhoff's law. Then, the estimated V–I$V–I$ characteristic is then compared with actual measurements to verify the feasibility of this novel approach. In the same manner, the capacitor parameter of the biohydrogen real-time power generating system can be estimated to identify the alternating current (AC) equivalent circuit for this system.     

Solar electric generating system resource requirements

The potential consumption of materials, land, water, manpower, energy, and money by four proposed solar electric generating systems: a terrestrial solar thermal, a terrestrial photovoltaic, an orbiting solar reflector, and a satellite solar power system are analyzed. The evaluation demonstrated that, per megawatt of electrical generating capacity, the terrestrial solar thermal system would require less manpower, less energy of production, and less money than would the extra-terrestrial systems.     

Impact of wind power generating system integration on frequency stabilization in multi-area power system with fuzzy logic controller in deregulated environment

Among the available options for renewable energy integration in existing power system, wind power is being considered as one of the suited options for future electrical power generation. The major constraint of wind power generating system (WPGS) is that it does not provide inertial support because of power electronic converters between the grid and the WPGS to facilitate frequency stabilization. The proposed control strategy suggests a substantial contribution to system inertia in terms of short-term active power support in a two area restructured power system. The control scheme uses fuzzy logic based design and takes frequency deviation as input to provide quick active power support, which balances the drop in frequency and tie-line power during transient conditions. This paper presents a comprehensive study of the wind power impact with increasing wind power penetration on frequency stabilization in restructured power system scenario. Variation of load conditions are also analyzed in simulation studies for the same power system model with the proposed control scheme. Simulation results advocates the justification of control scheme over other schemes.     

Forced convection and entropy generation inside a channel with a heat‐generating porous block

The flow pattern and heat transfer in a composite system containing a porous region has received considerable attention due to its importance in many engineering applications. In this study a thermal lattice Boltzmann model with nine velocities, D2Q9, is employed to investigate the fluid flow, heat transfer, and entropy generation inside a channel with a heat‐generating porous block. The effects of the porous block's length, porosity, and the Reynolds number, overflow pattern, heat transfer, and entropy generation were studied. The mentioned parameters have different effects on heat transfer and conjugate phenomena. By increasing the block length, Reynolds number, and porosity the dimensionless entropy generation will reduce. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21017     

Proportion assessment of combined PV-wind generating systems

The availability of sun and wind is often in contrast. This fact has led to the proposal of a combined generating system consisting of PV and Wind Generator. This paper introduces a method enabling the assessment of the optimal proportion of PV to wind generator capacities. The method is based on evaluation of costs and loss of load risk (LOLR). According to the Daily Electrical Energy Demand, the required generating system is designed with different alternatives: only PV, only wind generator and a combined PV and wind generator in various proportions. For each alternative, the costs and LOLR are evaluated. LOLR evaluation is performed using a probabilistic model introduced here. The alternatives are compared with each other and the optimal one is determined.     

“蓝天白煤”——风能在发电领域的应用研究

介绍了欧、美、日等发达国家风能利用现状。分析了辽宁省风力发电基本状况 ,提出了风力发电应解决的主要问题     

Simulation of a pilot solar chimney thermal power generating equipment

A pilot experimental solar chimney thermal power generating equipment was set up in China. A simulation study was carried out to investigate the performance of the power generating system based on a developed mathematical model. The simulated power outputs in steady state were obtained for different global solar radiation intensity, collector area and chimney height. By intercomparison, it is found that the simulated power outputs are basically in agreement with the results calculated with the measurements, which validates the mathematical model of the solar chimney thermal power generating system. Furthermore, based on the simulation and the specific construction costs at a specific site, the optimum combination of chimney and collector dimensions can be selected for a required electric power output.     

An approach to evaluate the general performance of stand-alonewind/photovoltaic generating systems

This paper reports the development of a computer approach for evaluating the general performance of stand-alone wind/photovoltaic generating systems. Simple models for different system components are developed, integrated, and used to predict the behavior of generating systems based on available wind/solar and load data. The model is useful for evaluating the performance of stand-alone generating systems and gaining a better insight in the component sizes needed before they are built. Simulation results are presented for performance evaluation of a stand-alone generating system that has been previously designed to supply the average power demand of a typical residential house. An electric water heater model is used as a dump load, and the excess available wind/solar-generated power is used to heat the water. The heated water is used as the inlet water to the main house water heater, which is assumed to be nonelectric. It is shown that this strategy can be effective in reducing the amount of fuel used by the main residential water heater     

Predictive maintenance in intelligent-control-maintenance-management system for hydroelectric generating unit

The predictive maintenance within the framework of intelligent-control-maintenance-management system (ICMMS) makes full use of all the information of control, maintenance, and technical management aspects to make right maintenance at the right time in the right place. In this paper, the three key elements of the predictive maintenance within the framework of ICMMS are presented. The ICMMS platform for hydroelectric generating unit, especially its maintenance function, is introduced. An artificial-neural-network (ANN)-based identification and diagnosis model is set up to implement the predictive maintenance of the electrohydraulic servomechanism in the hydroelectric generating unit. The tests show that the proposed strategy can guarantee ideal performance.