光伏电站用阀控式铅酸蓄电池

2002年,作为实施光明工程的一项重要举措,我国政府实施“西部省份无电乡通电工程项目”,利用国债资金在西部地区大部分无电乡兴建集中的光伏电站或风光互补电站,以彻底解决当地政府和居民基本用电问题。该项目对于改善项目所在地区人民生活水平、促进当地经济发展和推动国内新能源产业的发展,均具有非常重要的意义。1光伏电站的组成光伏电站是利用光电效应原理将太阳能转换为电能的发电系统。通常由太阳电池组件、控制器、蓄电池组、直流-交流逆变器等组成,其系统组成如图1所示。图1光伏电站系统组成示意图其工作原理为:白天,太阳电池组件接…     

光伏电站用蓄电池

早期的光伏电站用蓄电池，一般为开口式铅酸蓄电池。由于开口式铅酸蓄电池存在着需要定时加酸加水维护，酸液污染环境等缺点，不适于无人值守电站使用且不利于环境保护。随着阀控式铅酸蓄电池技术引入我国以及阀控式铅酸蓄电池在电信、电力、船舶、铁路等行业的成功使用，现在的光伏电     

配有蓄电池的独立光伏电站的仿真研究

本文介绍了用于配有蓄电池的独立光伏电站的计算机仿真软件，利用该软件可以预测配有蓄电池的独立光伏电站的长期运行性能，从而为改进系统配置、提高系统的可靠性及经济性提供依据。本文讨论了该软件的数学模型、软件结构及实现方法。     

光伏系统中铅酸蓄电池合理运行的控制方法

本文将与有铅酸蓄电池的光伏系统按其运行方式分为两类，分别简单介绍了它们各自的组成及特点，并在此基础上综述了蓄电池合理运行的几种控制方法。     

密封铅酸蓄电池的应用特性分析

通过对密封铅酸蓄电池的三条重要应用特性曲线的分析，结合独立光伏系统的特点，进行了户用光伏电源中密封铅酸蓄电池工作状态的分析，给出了相互匹配的条件，特别是过放电压Ｖｄ的选择和放电容量Ｃｄ的选择。     

阀控式密封铅酸蓄电池的运行与维护

根据阀控式密封铅酸蓄电池的特点提出蓄电池的运行与维护措施.     

对铅酸蓄电池使用节能添加剂的探讨

一、前言 由于铅酸蓄电池社会保有量相当大,为了生产和使用铅酸蓄电池,要耗用大量的金属、非金属资源和大量的硫酸。据有关资料介绍,早在1973年全国每年生产铅酸蓄电池的投铅最已超过4万吨,如今将大大超过此数。从节约资源考虑,如何延长铅酸蓄电池的寿命,已引起人们的重视。     

光伏电站免维护蓄电池的维护分析

通过分析光伏电站用蓄电池工作特点和影响使用寿命的主要因素，提出了用纵向对比和横向对比的相对比较方法来准确判断蓄电池单体的工作状态，依据工作状态决定对应的维护措施，同时认为给予欠充电的落后电池以适量补充电是最为有效的维护。     

Advances in VRLA battery technology for telecommunications

Wide scale use of the newly emergent VRLA (valve-regulated lead-acid) battery in telecommunication applications and the subsequent problems encountered early in their deployment history spurred intense efforts to improve the design as a continuous endeavor. After implementing improvements to battery placement and containment design to prevent the sudden onset of thermal runaway, the focus of the development work has been on cell internals. These include improved grid and strap alloys, superior AGM (absorbent glass mat) separator that retains compression in the cell, use of beneficial additives to the active materials and the need to avoid contaminants that promote detrimental side reactions. These improvements are now resulting in a vastly superior VRLA experience in the telecommunication applications. To further improve the reliability demanded by today's communication and internet environment VRLA battery installations should include continuous cell/module and system monitoring similar to that incorporated in competing advanced battery systems under development.     

System dynamic model and charging control of lead-acid battery for stand-alone solar PV system

The lead-acid battery which is widely used in stand-alone solar system is easily damaged by a poor charging control which causes overcharging. The battery charging control is thus usually designed to stop charging after the overcharge point. This will reduce the storage energy capacity and reduce the service time in electricity supply. The design of charging control system however requires a good understanding of the system dynamic behaviour of the battery first. In the present study, a first-order system dynamics model of lead-acid battery at different operating points near the overcharge voltage was derived experimentally, from which a charging control system based on PI algorithm was developed using PWM charging technique.The feedback control system for battery charging after the overcharge point (14 V) was designed to compromise between the set-point response and the disturbance rejection. The experimental results show that the control system can suppress the battery voltage overshoot within 0.1 V when the solar irradiation is suddenly changed from 337 to 843 W/m². A long-term outdoor test for a solar LED lighting system shows that the battery voltage never exceeded 14.1 V for the set point 14 V and the control system can prevent the battery from overcharging. The test result also indicates that the control system is able to increase the charged energy by 78%, as compared to the case that the charging stops after the overcharge point (14 V).     

Influence of the charge regulator strategy on state of charge and lifetime of VRLA battery in household photovoltaic systems

By simulating real working conditions of household photovoltaic system, the effects of overcharging on lifetime of valve-regulated lead-acid (VRLA) battery in solar home systems have been investigated; and the influences of three kinds of charge regulator strategies on state of charge and lifetime of VRLA battery have also been studied by experiments. A quantitative analysis of the VRLA battery behaviour under different charge regulator strategies was carried out. It is found that the temperature compensation of the end-of-charge voltage is necessary for VRLA battery, particularly in hot climates. The linear temperature compensation for the end-of-charge voltage keeps VRLA battery the best state of charge compared with other charge regulator strategies. Based on our results, the design engineers can choose a cost-effective regulator according to the details of photovoltaic system and local climate, and can estimate working state of VRLA battery installed in a system correctly, so as to extend VRLA battery lifetime in solar home systems. The clarification of the performance difference of VRLA battery under different regulators may be an important issue for determining life-cycle costs and servicing requirements.     

超级电容器-蓄电池应用于独立光伏系统的储能设计

建立了混合储能系统的数学模型,对模型系统进行了稳定性分析,从应用角度出发,设计了一套超级电容器-蓄电池混合储能装置应用在独立光伏系统,使用PSPICE软件仿真分析了系统的运行特性,结果表明系统在光伏输入功率大幅波动以及负载突变时具有很好的稳定性,可为超级电容器应用于可再生能源发电和电能质量改善等领域提供较好的参考。     

A sizing method for stand-alone PV installations with variable demand

The practical applicability of the considerations made in a previous paper to characterize energy balances in stand-alone photovoltaic systems (SAPV) is presented. Given that energy balances were characterized based on monthly estimations, the method is appropriate for sizing installations with variable monthly demands and variable monthly panel tilt (for seasonal estimations).The method presented is original in that it is the only method proposed for this type of demand. The method is based on the rational utilization of daily solar radiation distribution functions. When exact mathematical expressions are not available, approximate empirical expressions can be used. The more precise the statistical characterization of the solar radiation on the receiver module, the more precise the sizing method given that the characterization will solely depend on the distribution function of the daily global irradiation on the tilted surface H_gβi.This method, like previous ones, uses the concept of loss of load probability (LLP) as a parameter to characterize system design and includes information on the standard deviation of this parameter (σ_LLP) as well as two new parameters: annual number of system failures (f) and the standard deviation of annual number of system failures (σ_f).This paper therefore provides an analytical method for evaluating and sizing stand-alone PV systems with variable monthly demand and panel inclination. The sizing method has also been applied in a practical manner.     

Approaches for developing a sizing method for stand-alone PV systems with variable demand

Accurate sizing is one of the most important aspects to take into consideration when designing a stand-alone photovoltaic system (SAPV). Various methods, which differ in terms of their simplicity or reliability, have been developed for this purpose. Analytical methods, which seek functional relationships between variables of interest to the sizing problem, are one of these approaches.A series of rational considerations are presented in this paper with the aim of shedding light upon the basic principles and results of various sizing methods proposed by different authors. These considerations set the basis for a new analytical method that has been designed for systems with variable monthly energy demands.Following previous approaches, the method proposed is based on the concept of loss of load probability (LLP)—a parameter that is used to characterize system design. The method includes information on the standard deviation of loss of load probability (σ_LLP) and on two new parameters: annual number of system failures (f) and standard deviation of annual number of failures (σ_f).The method proves useful for sizing a PV system in a reliable manner and serves to explain the discrepancies found in the research on systems with LLP<10⁻². We demonstrate that reliability depends not only on the sizing variables and on the distribution function of solar radiation, but on the minimum value as well, which in a given location and with a monthly average clearness index, achieves total solar radiation on the receiver surface.     

Model construction and energy management system of lithium battery,PV generator,hydrogen production unit and fuel cell in islanded AC microgrid

The external electrical characteristics of the lithium battery, PV generator, hydrogen production unit (HPU) and fuel cell in islanded AC microgrid are well analyzed with mathematic models, based on which an energy management system among the abovementioned elements is proposed by using the bus frequency signaling. Specifically, the functions of lithium battery with the variables of the residual capacity and instantaneous working power are well designed to deliver its operation information to other units. The P-f droop control strategy is designed for the PV generator to make it adaptively work off from the maximum power point to the reference power point. The control strategy of HPU can make it work from the maximum efficiency point mode to the allowable maximum power point mode to absorb PV output power as much as possible when the lithium battery is almost getting full charged. Similarly, the fuel cell controller can regulate its power generation from the maximum efficiency point mode to the maximum power point to supply the local load as much as possible when the lithium battery is almost getting full discharged. Finally, the proposed energy management system is verified based on RTLAB experimental platform to show the effectiveness of the proposed coordination control strategy.     

Peak-power reduction with 100 kW PV and battery combined system at Shonan Institute of Technology

The grid connected 100 kW PV and 345 kWh battery combined system introduced in 1998 at Shonan Institute of Technology has been investigated. The system, equipped with PV and large battery, has a peak cut function against the big surge in electric power consumption in summer as well as working as an emergency electric power source. The daily peak of power consumption during summer occurs at 2:00 p.m. This time does not coincide with the time of peak power generation. The use of the PV/battery combined peak cut function effectively cuts consumption by 7% during the peak consumption period.     

Estimation of equivalent circuit parameters of PV module and its application to optimal operation of PV system

A method to estimate the equivalent circuit parameters of a PV (photovoltaic) module is presented. The parameters are calculated using a least-squares fitting of the equivalent model current–voltage characteristic with the measured one. For applications of the equivalent circuit model parameters, a quantitative diagnostic method of the PV modules by evaluating the parameters is introduced and examined by simulation. A new maximum peak power tracking (MPPT) method using the model parameters, a solar insolation, and a cell temperature is also shown. Its performance is compared with other MPPT control algorithms by simulations. The performance of the proposed method was better than other MPPT methods.