PSO-BP-Based Optimal Allocation Model for Complementary Generation Capacity of the Photovoltaic Power Station

To improve the operation efficiency of the photovoltaic power station complementary power generation system,an optimal allocation model of the photovoltaic power station complementary power generation capacity based on PSO-BP is proposed.Particle Swarm Optimization and BP neural network are used to establish the forecasting model,the Markov chain model is used to correct the forecasting error of the model,and the weighted fitting method is used to forecast the annual load curve,to complete the optimal allocation of complementary generating capacity of photovoltaic power stations.The experimental results show that thismethod reduces the average loss of photovoltaic output prediction,improves the prediction accuracy and recall rate of photovoltaic output prediction,and ensures the effective operation of the power system.

Energy conversion materials for the space solar power station

Since it was first proposed,the space solar power station(SSPS)has attracted great attention all over the world;it is a huge space system and provides energy for Earth.Although several schemes and abundant studies on the SSPS have been proposed and conducted,it is still not realized.The reason why SSPS is still an idea is not only because it is a giant and complex project,but also due to the requirement for various excellent space materials.Among the diverse required materials,we believe energy materials are the most important.Herein,we review the space energy conversion materials for the SSPS.

Assessment of Effects of Qinshan Nuclear Power Station on the Ecological Environment and Water Quality of its Adjacent Waters after its Running

On the basis of the data of biological and nonbiological factors collected respectively from 1989 to 1990 and from 1995 to 1996 in the waters nearby the Qinshan Nuclear Power Station, the ecological environment and water quality of the waters are analyzed and assessed in the paper. The results show: (a) the surveyed area has the typical ecological characteristics of high tidal range estuary, rich nutrients and low biological productivity, (b) tide, runoff and offshore seawater intrusion are the key factors which result in seasonal and annual changes of various biological and non-biological factors, (c) the risking of seawater eutrophication index is resulted from enormous amount of the discharges of industrial and domestic sewage, (d) because the survey area is located in a high tidal-range estuary, thermal effluent from cooling system does not induce significant temperature changes, ( e) the first stage project of Qinshan nuclear power station has no notable impacts on the ecological environment in

Phytoplankton ecology in the adjacent waters of the Daya Bay Nuclear Power Station in Guangdong in spring

The purpose of this study is to detail the ecological characteristics of phytoplankton in waters around the Daya Bay Nuclear Power Station in Guangdong (GNPS) (Fig. 1) in spring, the bloom period of algae. The collections with a small temporal scale of every three days were made during 30 cruises from March to May in 1987. Such an investigation has never been carried out before in China except that the seasonal distribution and composition of phytoplankton in these regions were reported in

Performance on Power,Hot and Cold Water Generation of a Hybrid Photovoltaic Thermal Module

This paper proposed a new function of photovoltaic thermal(PVT)module to produce nocturnal cool water not just only generating electrical power and hot water during daytime.Experimental tests were carried out under Chiang Mai tropical climate with a 200 Wp monocrystalline PVT module having dimensions of 1.601 m×0.828 m connected with two water tanks each of 60 L taken for hot and cool water storages.The module was facing south with 18o inclination.The electrical load was a 200 W halogen lamp.From experiments,by taking the module as a nocturnal radiative cooling surface,the cool water temperature in the cool storage tank could be reduced 2℃–3℃each night and the temperature could be reduced from 31.5℃to 22.1℃within 4 consecutive days.The cool water at approximately 23℃was also used to cool down the PVT module from noon when the PVT module temperature was rather high,and then the module temperature immediately dropped around 5℃and approximately 10%increase of electrical power could be achieved.A set of mathematical models was also developed to predict the PVT module temperature and the hot water temperature including the cool water temperature in the storage tanks during daytime and nighttime.The simulated results agreed well with the experimental data.

Seasonal Distribution of Manganese in the Soil-Water-Plant in the Zone of Burshtyn Thermal Power Station

This study deals with the impact of Burshtyn thermal power station on the amount of manganese in soil, water and celandine tissue. The research of manganese amount and form in the system： water-plant is of great importance due to active influence of thermal power station on the chemical structure of the polluted area. The changes in the amount and form of manganese in soil, water and plant are interrelated and depend on the season, the distance from the polluter and morph-functional plant structure, the cleaning system possibilities of the industrial enterprise and some meteorological factors.

Solar Energy Resource Characteristics of Photovoltaic Power Station in Shandong Province

[Objective] The aim was to analyze characters of solar energy in photo- voltaic power stations in Shandong Province. [Method] The models of total solar radiation and scattered radiation were determined, and solar energy resources in pho-tovoltaic power stations were evaluated based on illumination in horizontal plane and cloud data in 123 counties or cities and observed information in Jinan, Fushan and Juxian in 1988-2008. [Result] Solar energy in northern regions in Shandong proved most abundant, which is suitable for photovoltaic power generation; the optimal angle of tilt of photovoltaic array was at 35°, decreasing by 2°-3° compared with local latitude. Total solar radiation received by the slope with optimal angle of tilt exceeded 1 600 kw.h/（m2.a）, increasing by 16% compared with horizontal planes. The maximal irradiance concluded by WRF in different regions tended to be volatile in 1 020-1 060 W/m2. [Conclusion] The research provides references for construction of photovoltaic power stations in Shandong Province.

Slag-washing water of blast furnace power station with supercritical organic Rankine cycle

Organic Rankine cycle(ORC) power plant operating with supercritical parameters supplied by low temperature slag-washing water(SWW) of blast furnace was investigated.A schematic of such installation was presented with a description of its operation and the algorithm of calculations of a supercritical power plant.Two typical organic fluids with sufficiently low critical parameters were selected as candidate working fluids in the plant to study the efficiency of the system with different organic fluids.An analysis of the influence on the effectiveness of operation of a plant was carried out.With the same temperature of slag-washing water,the specific work in turbine of fluid R143a is 45% higher than that obtained for the fluid R125,however,the specific work in pump of fluid R143a is approximate equal into that one of the fluid R125.

Environmental Ecological Response to Increasing Water Temperature in the Daya Bay, Southern China in 1982-2012

The increase of water temperature, due to thermal discharges from two nuclear power stations, was one of the most significant environmental changes since 1982 in the Daya Bay, located in the north of the South China Sea. This study investigates the long-term (1982-2012) environmental changes in Daya Bay in response to the increase of water temperature, via comprehensively interpreting and analyzing both satellite and in situ observations along with previous data. The results show that: 1) salinity, dissolved oxygen (DO), chemical oxygen demand (COD) and nutrients had been enhanced after the thermal discharges started in 1994;2) the concentration of Chl-a increased while the net-phytoplankton abundance decreased;3) diversity of the phytoplankton community had decreased;4) fishery production had declined;and 5) frequency of Harmful Algal Bloom occurrence had increased. Satellite images show clearly that a thermal plume from the power stations extended toward the interior of Daya Bay, and that surface temperature of the seawater increased as one approached the power stations. The analysis suggests that the thermal water discharged from the two power stations was a driver of the ecosystem’s change in Daya Bay. Several factors, including nutrients, salinity, DO, and COD, varied according to the increase of water temperature. These factors affected the water quality, Chl-a, and phytoplankton in the short term and impaired aquatic organisms and the whole ecosystem in the long term.

Changes of Water Temperature and Harmful Algal Bloom in the Daya Bay in the Northern South China Sea

Economic development around the Daya Bay, China has profoundly affected the marine environment in the bay area in recent years, particularly since the operation of Daya Bay Nuclear Power Station （DNPS） in 1994. This study analyzed the changes of water temperature and harmful algal blooms （HABs） for two periods： 1983-1993 and 1994-2004, using in situ and satellite data. Results showed that yearly mean surface water temperature （SWT） and Chl-a concentration （Chl-a） increased by 1.1 ℃ and 1.9 mg/m^3, respectively, after 1994. The monthly occurrence of HAB was found to have increased also. HABs appeared only in spring and autumn before 1994, but occurred all the year round after 1994. SWT, Chl-a and HABs all increased significantly in May. Those changes were associated with environmental changes in this area, such as thermal discharge from the DNPS and enhancement of eutrophication from human activities around the Daya Bay.

Distributed power conditioning unit of large-scale space solar power station

In this paper,a multi-bus distributed Power Conditioning Unit(PCU)is proposed for the Space Solar Power Station with large scale photovoltaic(PV)array and power levels reaching MW level.In this unit,there are multiple independent PV arrays.In each PV array,there are multiple independent PV subarrays.In this paper,a V-P droop control method with adaptive droop coefficient is proposed,which modifies the droop intercept based on the bus voltage deviation and the power per unit value of the PV array.This method ensures the accuracy of bus voltage and achieves proportional distribution of power between PV arrays based on the proposed topology structure in this paper.When the load changes or the output power of the PV array fluctuates,this method can ensure that power is distributed proportionally.The principle and control method of the proposed droop control method is analyzed in this paper.The effectiveness of the method is verified through MATLAB/Simulink simulation and experiment.Simulation and experimental results show that the proposed method can achieve power distributed proportionally when load changes and PV output power fluctuates,reduce bus voltage error caused by line impedance and differences in rated power of different PV arrays,and improve the performance of PV power generation system applied to space.

Recent Progress on Thermal Energy Storage for Coal-Fired Power Plant

With countries proposing the goal of carbon neutrality,the clean transformation of energy structure has become a hot and trendy issue internationally.Renewable energy generation will account for the main proportion,but it also leads to the problem of unstable electricity supply.At present,large-scale energy storage technology is not yet mature.Improving the flexibility of coal-fired power plants to suppress the instability of renewable energy generation is a feasible path.Thermal energy storage is a feasible technology to improve the flexibility of coal-fired power plants.This article provides a review of the research on the flexibility transformation of coal-fired power plants based on heat storage technology,mainly including medium to low-temperature heat storage based on hot water tanks and high-temperature heat storage based on molten salt.The current technical difficulties are summarized,and future development prospects are presented.The combination of the thermal energy storage system and coal-fired power generation system is the foundation,and the control of the inclined temperature layer and the selection and development of molten salt are key issues.The authors hope that the research in this article can provide a reference for the flexibility transformation research of coal-fired power plants,and promote the application of heat storage foundation in specific coal-fired power plant transformation projects.

An optimal strategy for coordinating and dispatching “source-load” in power system based on multiple time scales

Due to the phenomenon of abandoning wind power and photo voltage(PV)power in the“Three Northern Areas”in China,this paper presents an optimal strategy for coordinating and dispatching“source-load”in power system based on multiple time scales.On the basis of the analysis of the uncertainty of wind power and PV power as well as the characteristics of load side resource dispatching,the optimal model of coordinating and dispatching“source-load”in power system based on multiple time scales is established.It can simultaneously and effectively dispatch conventional generators,wind plant,PV power station,pumped-storage power station and load side resources by optimally using three time scales:day-ahead,intra-day and real-time.According to the latest predicted information of wind power,PV power and load,the original generation schedule can be rolled and amended by using the corresponding time scale.The effectiveness of the model can be verified by a real system.The simulation results show that the proposed model can make full use of“source-load”resources to improve the ability to consume wind power and PV power of the grid-connected system.

风光热储互补发电系统容量配置技术研究

针对无常规电源支撑的风光热储互补发电系统,协调规划装机容量对提高发电系统运行经济性和利用率具有重要意义。提出了一种双层优化配置方法,上层以最小度电成本及弃电率为目标,确定系统装机容量;下层以新能源发电消纳最大为目标,解决功率分配问题。通过反复迭代寻优,得到系统容量配置;然后;通过纳什谈判对优化结果进行选择;最后,对甘肃河西地区数据进行仿真分析。结果表明:风光热储互补发电系统最优容量配置下的度电成本为0.3064元/(k W·h);风电场加光伏电站装机容量与光热电站装机容量的最优比为6:1,对比相同装机容量的风光互补发电系统,风光热储互补发电系统具有更高的稳定性。

新能源场站快速有功控制及频率支撑技术综述

以光伏/风电为代表的新能源高比例并网降低了电力系统的惯量水平和频率支撑能力,频率稳定问题成为当前电网安全稳定和新能源高效消纳的核心问题之一。发展新能源发电并网机组单元和场站的快速有功频率响应和主动支撑能力是当前的研究热点。该文以“单机快速有功控制-场站快速有功控制-场站快速频率支撑”为主线,梳理光伏/风电的快速有功控制及频率支撑发展现状,分析频率检测、通信延时和控制响应模式等因素对光伏/风电场站频率响应快速性的影响,指出风电机组的机械载荷约束、风电场百毫秒级有功控制、场站的调频响应模式选择和优化、暂态有功无功协同控制是提升新能源发电单元和场站的快速有功频率响应能力的4个关键问题,最后对未来的重点研究方向进行展望和讨论。

计算机视觉的电站锅炉水冷壁缺陷检测方法

发电厂锅炉巡检可有效避免安全事故发生,针对现场巡检过程中,锅炉水冷壁巡检区域较大,部分区域检测困难问题,开发一种基于YOLOv3模型的水冷壁缺陷检测系统。无人机携带视觉采集装置,对豫能集团某电厂锅炉水冷壁进行图像采集,画面经压缩后实时无线传输到检测末端装置,采用YOLOv3算法对水冷壁数据进行分析,对模型重要参数进行调整并做出样本增广与平衡化改进处理,提高检测效果,共测出磨损、裂缝、氧化等106处失效部位,与人工检测对比,成功率达77.9%。该方法解决了在巡检区域大、部分区域检测困难问题,使大型电站锅炉在开展水冷壁检测方面实际付出的成本得到有效缩减。

光伏电站理论发电功率的优化计算模型与方法

光伏电站理论发电功率计算结果的准确性直接影响弃光电量的统计,对电网调度及光伏发展规划影响重大。理论发电功率的传统计算方法有样板逆变器法和气象数据外推法,当样板逆变器的出力受到限制时,样板逆变器法计算结果不准确,而气象数据外推法参数众多且难以确定。针对上述问题,提出了一种光伏电站理论发电功率优化计算方法。首先,介绍了样板逆变器法和气象数据外推法的计算原理,并分析了两种方法的特点和不足。然后,基于光伏电站历史出力及气象信息,提出了改进样板逆变器法和改进气象数据外推法。在实际应用中,当弃光未发生或者在弃光初始阶段采用计算精度更高的改进样板逆变器法开展计算,当样板逆变器出力受到限制时,切换至改进气象数据外推法进行求解。最后,对国内某光伏电站在不同气象条件下开展仿真计算,验证了所提方法的合理性和有效性。

大型集中式光伏电站效率测试及提效对策研究

随着光伏电站的投产运行,光伏发电量的大小直接影响电站效益,如何科学的对光伏电站效率进行测试、分析与评价,提高电站发电效率,显得尤为重要。通过调研200 MW集中式光伏电站运行情况,研究光伏电站系统能效测试技术,制定电站测试项目、测试要求、抽样原则,开展光伏电站现场测试,并对电站系统效率、组件串联失配率、组串并联失配率、逆变器转换效率、组件衰减率、洁净度对光伏板功率影响度、倾角与辐照度测试结果进行分析,从减少弃光率、组件清洗、组件倾角调整以及运维管理水平等方面,提出针对性的提效对策,在提高电站系统效率的同时,进一步提升电站效益。

泰国LAMTAKONG抽水蓄能电站(U3 U4)供水系统设计与探讨

文中对泰国LAMTAKONG抽水蓄能电站(U3 U4)供水系统的设计、供水系统方案的选择、系统组成及主要设备选择进行了阐述,并对目前系统存在的问题及系统优化等进行了简单的分析与探讨,提出改进的建议,可为类似抽水蓄能电站供水系统设计提供参考和借鉴。

梯级泵站事故停机输水明渠水力过渡过程研究

为解决梯级泵站系统因超负荷、大流量、高水位运行出现垮渠、跳闸停机等事故,而导致水力过渡过程中出现进水前池被抽干或漫顶等问题,以甘肃省景泰川电力提灌二期工程长距离输水明渠为研究对象,在多梯级泵站事故停机产生溢流的工况下,基于Realizable k-ε和VOF模型进行数值模拟计算,分析景电二期工程1#~7#干渠在调蓄系统作用下,不同渠长、坡降的水面线以及水力振荡分布规律。结果表明:泵站停机后水位出现升降交替的水力振荡现象,影响各泵站波峰水位高度不一致的主要原因是渠道坡降;不同参数特征的渠道壅水波运动的回溯距离不同,溢流堰上发生溢流的时间主要在第一次水位振荡过程中。