Probabilistic analysis of weather data for a hybrid solar/wind energy system

In this paper, a procedure for the probabilistic treatment of solar irradiance and wind speed data is reported as a method of evaluating, at a given site, the electric energy generated by both a photovoltaic system and a wind system. The aim of the proposed approach is twofold: first, to check if the real probability distribution functions (PDFs) of both clearness index and wind speed overlap with Hollands and Huget and Weibull PDFs, respectively; and then to find the parameters of these two distributions that best fit the real data. Further, using goodness‐of‐fit tests, these PDFs are compared with another set of very common PDFs, namely the Gordon and Reddy and Lognormal functions, respectively. The results inform the design of a pre‐processing stage for the input of an algorithm that probabilistically optimizes the design of hybrid solar wind power systems. In this paper, the validity of the proposed procedure was tested using long‐term meteorological data from Acireale (Italy). Copyright © 2010 John Wiley & Sons, Ltd.     

新型户用风光互补供电系统

简要描述了新型户用风光互补供电系统及其应用示范情况,以一个典型的实例分析了系统运行情况。经过1年的运行证明,该系统设计合理,能够满足边远地区目前的用电需求,具有推广应用价值。     

Hybrid solar/wind power system probabilistic modelling for long-term performance assessment

This paper presents a probabilistic approach based on the convolution technique to assess the long-term performance of a hybrid solar–wind power system (HSWPS) for both stand-alone and grid-linked applications. To estimate energy performance of HSWPS the reliability analysis is performed by the use of the energy index of reliability (EIR) directly related to energy expected not supplied (EENS). Analytical expressions are developed to obtain the power generated. The hybrid system and the load models employed enable the study period to range from one year to one particular hour-of-day, thus allowing the inclusion of the time-value of energy as appropriate in economic assessments. A numerical example application is included to illustrate the validity of the developed probabilistic model: the results are compared to those resulting from time domain simulations.     

A demonstrative study for the wind and solar hybrid power system

In March 1995, a small scale wind and solar hybrid power system was installed at Ashikaga Institute of Technology. Until now, the authors have acquired the data of the output of the hybrid power plant along with wind speed, wind direction, and the solar radiation, in order to demonstrate a complementary relationship between solar energy and wind energy.After nine months operation of the system, the authors confirmed that there exists a complementary relationship between solar energy and wind energy. We also found, however, that the power output by wind does not have much prospect compared to that by solar cell especially in summer season in Ashikaga area.     

Performance evaluation of hybrid (wind/solar/diesel) power systems

Depleting oil and gas reserves, combined with the growing concerns of global warming, have made it inevitable to seek alternative/renewable energy sources. The integration of renewables such as solar and wind energy is becoming increasingly attractive and is being used widely, for substitution of oil-produced energy, and eventually to minimize atmospheric degradation. The literature shows that commercial/residential buildings in Saudi Arabia consume an estimated 10–40% of the total electric energy generated. In the present investigation, hourly wind-speed and solar radiation measurements made at the solar radiation and meteorological monitoring station, Dhahran (26°32′ N, 50°13′ E), Saudi Arabia, have been analyzed to investigate the feasibility of using hybrid (wind+solar+diesel) energy conversion systems at Dhahran to meet the energy needs of twenty 2-bedroom houses. The monthly average wind speeds for Dhahran range from 4.1 to 6.4 m/s. The monthly average daily values of solar radiation for Dhahran range from 3.6 kWh/m² to 7.96 kWh/m². The performance of hybrid systems consisting of different rated power wind farms, photovoltaic (PV) areas, and storage capacities together with a diesel back-up are presented. The monthly average daily energy generated from the above hybrid system configuration has been presented. The deficit energy generated from the back-up diesel generator and the number of operational hours of the diesel system to meet a specific annual electrical energy demand of 702,358 kWh have also been presented.     

Small hybrid solar power system

This paper introduces a novel concept of mini-hybrid solar power plant integrating a field of solar concentrators, two superposed Organic Rankine Cycles (ORC) and a (bio-)Diesel engine. The Organic Rankine Cycles include hermetic scroll expander-generators¹ and the sun tracking solar collectors are composed of rows of flat mirror bands (CEP) arranged in a plane, that focus the solar energy onto a collector tube similar to those used in SEGS plants in California. Waste heat from both the exhaust gases and the block cooling of the thermal engine are also heat sources for the ORCs. Such units meet electricity, cooling and pumping needs of remote settlements. The thermal engine guarantees a minimum level of both power and heat availability at night or during cloudy periods. Laboratory tests, made with the superposed ORCs only, confirmed adequate operational characteristics with good performances over a broad range of conditions. A few preliminary tests on the site of the solar power plant when coupled with the engine confirmed a reasonable behavior and the interest of the concept even at part load or during sharp variations of the thermal supply.     

Modeling of hybrid photovoltaic/wind/fuel cells power system

In this paper, identification and modeling of a hybrid photovoltaic/wind/fuel cells power system is presented. This system comprises also a battery storage supplying a load via an inverter. The identification of each subsystem has been made and then the proposed system is modeled and simulated under Matlab/Simulink Package. The power control of the hybrid system is introduced by using LabVIEW Software. The mathematical model topology and its power management of the global system with battery bank system are significant contributions of our work. The proposed control strategy has been experimentally implanted and practical results are compared to those obtained by simulation under the same metrological conditions, showing the effectiveness of the proposed hybrid system.     

风光互补独立供电系统优化匹配设计实例

以系统的最小安装成本为优化目标,以系统的供电可靠性为约束条件,对内蒙古满洲里市某居民家庭用电风光互补独立供电系统进行基于计算机仿真计算的优化匹配设计。     

Sizing optimization of grid-independent hybrid photovoltaic/wind power generation system

To allow a real penetration of the huge dispersed naturally renewable resources (wind, sun, etc.) intermittent and more or less easily predictable, optimal sizing of hybrid renewable power generation systems prove to be essential. This paper recommends an optimal sizing model based on iterative technique, to optimize the capacity sizes of different components of hybrid photovoltaic/wind power generation system using a battery bank. The recommended model takes into account the submodels of the hybrid system, the Deficiency of Power Supply Probability (DPSP) and the Levelised Unit Electricity Cost (LUEC). The flow chart of the hybrid optimal sizing model is also illustrated. With this incorporated model, the sizing optimization of grid-independent hybrid PV/wind power generation system can be accomplished technically and economically according to the system reliability requirements. A case study is conducted to analyze one hybrid project, which is designed to supply residential household located in the area of the CDER (Center for Renewable Energy Development) situated in Bouzaréah, Algeria (36^° 48′N, 3^° 1′E, 345 m).     

风光互补发电系统中光伏方阵最佳倾角的计算方法

介绍一种计算风光互补发电系统中光伏方阵的最佳倾角的方法。用最小二乘法确定光伏方阵的最佳倾角:先计算出倾角β下各月倾斜面上的太阳能方阵发电量与风机发电量之和,然后减去各月负载耗电量的差,再求出一年内上述差值的平方和,能使得此平方和取得最小值的倾角即为方阵最佳倾角β。根据此方法确定出的最佳倾角可以使太阳能和风机发电量相对不足的月份的发电量尽量接近负载需求量,同时又可以解决有的月份风光发电量远大于负载需求,造成极大浪费的问题。     

聚光式太阳能动力与制冷联合热发电系统

1前言从20世纪90年代到现在,国内外聚光式太阳能热发电系统是以聚光式太阳能锅炉取代矿物燃料锅炉,并联辅助常规能源锅炉和蓄热器进行发电的。太阳能热发电系统在热力学原理上也是按朗肯循环或勃莱顿循环运行的,而卡诺循环效率η_卡是工作于两个一定温度之间的所有热机效率η_(热机)的理论     

Triple hybrid system coupling fuel cell with wind turbine and thermal solar system

One of the most challenging issues in the domain of renewable energy is the instability of produced power. To put it another way, renewable resources such as solar energy cannot provide continuous energy supply because they rely on natural phenomena that vary randomly. That said, to cover the potential lack of energy that may occur, hybrid renewable energy system can be adopted. In other terms, instead of using single renewable energy source, two different sources can be utilized in order to optimize the output power all over the year. Furthermore, complementary energy system is needed along with renewable sources, to store energy and insure the supply during shortage period. With this in mind, a Green-Green energy system can be constructed by using green storage system such as Fuel Cell to be coupled with the renewable sources. In the light of green-green energy concept, the present paper examines a triple wind-solar-fuel cell combination in the aim of overcoming the energy shortage that occurs during several months of the year. A case study on the region of Dahr Al-Baidar in Lebanon is conducted to present the advantage of the proposed system. Results show that combining wind energy system with thermal solar system allows overcoming the low power produced by solar thermal system especially in winter. For illustration 16 kW are produced by wind turbine during the month of January, by contrast the thermal solar system provides 2 kW during the same period. Nevertheless, in June thermal solar offers 17 kW and wind turbine produces 11 kW.     

离网型风光互补发电系统的研制与应用

一引言 风光互补发电系统是一种将光能和风能转化为电能的装置,由于太阳能与风能的互补性强,该系统能弥补风电和光电独立系统在资源上的间断不平衡性、不稳定性.可以根据用户的用电负荷情况和资源条件对系统容量进行合理配置,既保证供电的可靠性,又降低发电系统的造价.同时,风光互补发电系统是一套独立的分散式供电系统,可不依赖电网独立供电,不消耗市电,不受地域限制,既环保又节能,还可作为一道典雅的风景为城市景观增姿添彩.     

A hybrid TEG/wind system using concentrated solar energy and chimney effect

This paper investigates a novel hybrid system combining thermal electrical generators (TEGs) and a wind turbine. The mathematical model of the system is derived and solved to investigate the performance of the proposed system. In the proposed system, solar energy is converted to heat by an absorber plate. Some portion of this heat is converted to electricity using TEG, while another portion of the heat is used to heat up air flowing in an inclined duct placed underneath the absorber plate. Heating the air inside the system enhances the current speed because of the effect of buoyancy. A wind turbine is placed inside the duct parallel to air flow before it exits to the atmosphere. The wind current is accelerated before passing through the turbine by using venture effect. The TEGs are exposed to the concentrated solar radiation. This can be obtained using a compound parabolic concentrator. The proposed configuration has multiadvantages: (1) the wind is used to drive a wind turbine; (2) air cools the rear surfaces of TEGs to increase the temperature difference between the opposite surfaces, thus generates more electrical power; and (3) it uses buoyancy effect to increase the wind stream speed, thus enhancing the power generated from turbine. It is found that the solar concentration ratio is the most important factor contributing to enhancing the TEG efficiency. The buoyancy effect leads to turbine power boost at high wind speeds more than at low wind speeds.     

基于复合控制的塔式太阳能跟踪控制装置设计

针对塔式太阳能热发电站中定日镜跟踪装置的跟踪精度不高、构建成本较大等问题,提出采用将遗传算法的选择机制与吸热塔能量变化的反馈机制相结合的方式对光热电站的太阳能跟踪控制系统进行改进.在光热电站的少数几台定日镜上配备光电检测元件,并以其控制角度为基准控制其他定日镜的角度调整.采用DSP(digital signal processing)为控制核心,完成了跟踪控制器的通讯框架及控制系统的硬件电路设计.实验表明,该方案在保证光热电站整体控制精度的基础上,减少了光电检测元件安装数量和电站构建成本,并保证了视日轨迹跟踪控制时的自动调整能力.     

隧道式烟囱太阳热风发电系统

太阳热风发电系统的基本原理如图1所示，由3个主要部件构成：底部为太阳能空气加热器（集热棚），中间为太阳能烟囱，烟囱底部布置风力发电机组。太阳辐射加热玻璃屋顶下温室内的空气，致使热空气源源不断流向位于温室中央的太阳能烟囱；烟囱两端空气的温差和压差导致空气沿太阳能烟囱上升产生动能，在烟囱内安装风力透平发电机，产生电能，风最后从烟囱顶部排入大气。其能量流向为太阳光能先变成空气的热能，再转变为风的动能，再转变为风力透平的动能，最后得到电能。     

A mobile renewable house using PV/wind/fuel cell hybrid power system

A photovoltaic/wind/fuel cell hybrid power system for stand-alone applications is proposed and demonstrated with a mobile house. This concept shows that different renewable sources can be used simultaneously to power off-grid applications. The presented mobile house can produce sufficient power to cover the peak load. Photovoltaic and wind energy are used as primary sources and a fuel cell as backup power for the system. The power budgeting of the system is designed based on the local data of solar radiation and wind availability. Further research will focus on the development of the data acquisition system and the implementation of automatic controls for power management.     

风光互补式微网海水淡化系统

淡水资源和常规能源短缺是限制海岛开发和海洋经济发展的主要因素。新能源海水淡化具有环境友好、供水保障率高、经济合理等优点,逐渐成为离岸中小岛屿供水保障研究的热点。文章在充分调查分析海岛新能源资源及其发电输出功率特点和海水淡化装置对电能质量要求的基础上,设计了新型独立微网能源管理策略,形成了成套的风光互补式微网海水淡化技术,并进行了工程应用。结果表明,风光互补式微网海水淡化系统运行稳定,对环境的适应能力强,适于解决岛屿的饮用水问题。在风、光等可再生能源资源较丰富、海水资源良好的海岛,风光互补式海水淡化系统的综合制水成本约为10元/m3,相对于大陆引水、船舶运水等其他岛内淡水供应方式具有明显的经济和生态环境优势,具有较为广阔的推广应用前景。     

Probabilistic small signal stability analysis of power system with wind power and photovoltaic power based on probability collocation method

Recently, with increasing improvements in the penetration of wind power and photovoltaic power in the world, probabilistic small signal stability analysis (PSSSA) of a power system consisting of multiple types of renewable energy has become a key problem. To address this problem, this study proposes a probabilistic collocation method (PCM)-based PSSSA for a power system consisting of wind farms and photovoltaic farms. Compared with the conventional Monte Carlo method, the proposed method meets the accuracy and precision requirements and greatly reduces the computation; therefore, it is suitable for the PSSSA of this power system. Case studies are conducted based on a 4-machine 2-area and New England systems, respectively. The simulation results show that, by reducing synchronous generator output to improve the penetration of renewable energy, the probabilistic small signal stability (PSSS) of the system is enhanced. Conversely, by removing part of the synchronous generators to improve the penetration of renewable energy, the PSSS of the system may be either enhanced or deteriorated.     

光伏发电的六象限法太阳自动跟踪系统

为了增加太阳能电池的输出功率,往往采用光伏板自动跟踪太阳的方法。文章在传统的四象限法跟踪基础上,设计了一种六象限法光电式太阳位置检测跟踪装置。采用STC12C5A60S2单片机作为控制芯片,以步进电机作为执行机构,通过单片机控制双步进电机,实现双轴太阳自动跟踪。实验表明,该系统不仅可以实现对太阳的自动跟踪,而且能提高对太阳跟踪的稳定性,具有较高的实用价值。