面向未来的大型水力机械关键技术研究

习近平总书记在第七十五届联合国大会一般性辩论上发表重要讲话时指出,中国将提高国家自主贡献力度,采取更加有力的政策和措施,二氧化碳排放力争于2030年前达到峰值,努力争取2060年前实现碳中和。这是中国对碳排放达峰、长期碳中和问题设立的更高目标。     

Flexible HVDC Transformer for Next Generation Renewable Energy Industry

The growing demand on non-fossil fuel energy has escalated the desire for mega-scale renewable energy power generation, which can no longer be satisfied solely by relying on onshore renewable energy power plants. Outcomes from a recent project funded by the Sixth European Union Framework Programme （FP6）, Project ＂Upwind＂ concluded that larger offshore wind turbines （i.e., 〉 10 MW） are feasible and cost effective. It will be beneficial for such future large scale renewable energy power generators （i.e., large offshore turbines） and plant （i.e., large offshore wind farms） to have a dedicated high efficiency, robust, flexible and low cost power collection, transmission and distribution technology. Proposed in this paper is a compact and effective hybrid HVDC （high voltage direct current） transformer that allows realisation of a highly robust and financially rewarding next generation multi-terminal HVDC system for future offshore renewable energy power plant. This concept, potentially, allows the elimination or minimisation of the need for a centralised local offshore HVDC platform or substation in each wind farm, solar farm, or tidal farm. This paper discusses the study outcome of the proposed hybrid HVDC transformer and the application of a multi-terminal HVDC system in the renewable energy industry, compared to the existing HVAC and VSC （voltage source converters） type HVDC systems.     

下一代全球电网的基本模式

分析了智能电网在国际能源革命中的战略地位和中美两国能源效率改革的不同发展路径,提出互动电网是中国电网现代化的核心,是下一代全球电网的基本模式。阐述了互动电网释源,并结合中国国情给出了中国互动智能电网体系构架原则和技术流程要素。     

电力市场环境下水电竞价策略研究

针对电力市场化改革是一个长期的实践探索过程、我国正积极研究和制定水电可持续发展的各项政策,结合水电机组自身特性探讨了水电机组参与合约市场、日前市场、AGC辅助服务市场的竞价策略和模式,对水电真正参与市场竞争提供参考依据.     

长期耗能最小发电调度模型及其求解方法

针对水电系统长期耗能量小问题设计了求解方法；首先定义一个搜索方向集。然后按等微增率原理，依次按对目标有利程度的大小顺序选择搜索方向逐时段进行系统负荷平衡，通过对福建水电站系统的应用，证明长期耗能最小发电调度模型及其求解方法具有耗时较少，能有效减少弃水等优点。     

Hydro energy potential of cooling water at the thermal power plant

The hydro energy of the gravity water flow from the coal-fired thermal power plant units to the river in an open cooling system of turbine condensers is determined. On the basis of statistical data for a long time period, the water net head duration curve due to the river annual level change, as well as the reduction of the hydro energy potential due to the thermal power plant overhauls periods, are evaluated in the case study of the Thermal Power Plant “Nikola Tesla B” in Serbia. A small hydro power plant is designed for the utilization of this hydro energy, and the economic benefits of the project are calculated. The internal rate of returns and pay back periods are calculated in dependence of the electricity price and total investment costs. The increase of profitability is assessed, bearing in mind that the plant might be realized as the Clean Development Mechanism project according to the Kyoto protocol. The obtained results show that the project is economically attractive, and it can be carried out with standard matured solutions of hydro turbines available at the market. Even for the relatively low electricity price from small hydro power plants in Serbia of 0.08 €/kW h the internal rate of return and the pay back period are 17.5% and 5.5 years.     

Next Generation Spray Cooling: High Heat Flux Management in Compact Spaces

For many years, spray cooling has been known as a promising technology for the removal of high heat fluxes. However, that promise has yet to be fully realized. This work presents a current understanding of the mechanisms of spray cooling and its limitations. To address these limitations, a novel spray nozzle array is described that allows for scalable, high-performance cooling. However, fluid management remains a challenging concern that may limit the application of this technology.     

小水电站增效扩容的径流和水能计算方法及应用

针对2011年全国性小水电站增效扩容项目文件中对老旧水电站更新改造的要求,在开展农村水电改造设计过程中,遵循《小型水电站水文计算规范》和《小水电水能设计规程》的规定,总结了有实测径流资料、引用相邻或相似流域水文资料、无径流实测资料三种条件下小水电站的水文径流和水能计算方法,并结合三座电站运行多年的统计数据进行核算或反推,求出拟改造条件下水电站水能指标,以此判断设计电站是否满足电量计算的增效扩容潜力不低于10%的要求。     

Advance Electronic Load Controller for Micro Hydro Power Plant

Most of the MHP （micro hydro power） plants use ELC （electronic load controller） for speed control. Various types of ELC have been developed so far. A dummy ballast load is connected across each phase of generator terminals and ELC controls the power consumed by the ballast load to result in constant speed operation. The ELC developed so far uses thyristor switches in each phase to control ballast load power. The ELC senses the system frequency and comparing it with reference frequency, it generates a common value of firing angle for all three thyristor pairs of each phase. The performance of such ELC is not perfect for unbalanced consumers load connected in each phase, which overloads the generator. This paper presents an advanced type of ELC which senses frequency as well as consumer＇s load current of each phase and fires the thyristor pairs with different value of firing angles for different phases. This solves the problem of overloading of the generator with unbalanced consumer＇s load. Simutink model is developed to perform transient analysis of the proposed scheme and the prototype of hardware is also fabricated. The simulation results and experimental results are presented.     

Innovative Control Strategy for Islanded Small Hydro Power Plant

In many developing countries, there are regions where the electrical grid is weak or nonexistent. However, in these areas, large amounts of distributed energy sources, such as hydro, are often available and could be suitably exploited. To this aim, the low head hydro power plants can play a significant role. In fact, recent technological advances in mini-hydro turbines and decreasing costs of static electricity conversion devices enable to realize suitable power plants for an efficient and profitable exploitation of these sites. One of the major challenges is the integration of the above-mentioned power plants into autonomous electrical systems, islanded and/or disconnectable from the main distribution network. In this paper, an innovative control strategy for a low head hydro power plant supplying users in small clusters of villages is proposed.     

An Overpumping Prevention System for the Rocky Mountain Pumped Storage Hydro Project

An overpumping prevention system was designed to protect the upper reservoir dam structures, and therefore the powerhouse and surrounding countryside, at the Rocky Mountain Pumped Storage Hydro Project. This system uses three independent systems for checking reservoir levels. Two of them automatically trip the units, if necessary. Fiber optic communications are used to link instrumentation at the upper reservoir to the powerhouse.     

基于Fluent的叶片展长对卧式水轮机水动力性能影响的数值研究

提出了一种能够利用波浪能发电的装置,其吸收海水能量的主要构件是卧式水轮机.为了研究卧式水轮机的水动力学性能,采用有限体积法,并利用非定常SST k-ω湍流模型和滑移网格技术,对其进行了三维数值模拟与实验研究,分析了在六种不同叶片展长下叶轮的水动力学特性.通过将数值计算结果和实验结果进行比较,验证了SST k-ω湍流模型和滑移网格技术的可行性.结果发现:叶片展长递增对水轮机叶片的合力系数几乎没有影响,但是对轮机转矩系数和叶轮能量利用率影响很大;在低尖速比时,叶片展长对水轮效率影响不大,当尖速比大于2.5时,叶片展长对水轮效率的影响明显加大;叶片展长越长,叶片切向力越大,水轮机对水能的吸收能力越强.     

HVDC Offers the Key to Untapped Hydro Potential

Long transmission lines are required to transmit power from remote generation sites to the population centers. When transmission is by AC, the large reactances of the long lines limit the power transmissibility. By siting FACTS controllers or HVDC stations, which have strong voltage support, at the midpoint of the lines, the transmission distance between voltage supported nodes is halved and so is the line reactance. Thus, the maximum steady-state power can be twice that of the original lines. Digital simulation comparison of a realistic AC transmission system shows that the gain factor, based on the steady-state stability limit, is only 1.59 and not 2. This paper reports on analysis undertaken to account for the discrepancy. The analysis shows that the distributed capacitance in the original long transmission line is already providing voltage support. For this reason, the voltage support by the midpoint sited FACTS controllers or HVDC stations becomes less significant. Furthermore, the FACTS controllers or HVDC stations are inserted at the midpoint through transformers, whose leakage reactances add to the line impedance.     

水轮机调节系统被控对象模型辨识

建立了水轮机调节系统被控对象的非线性模型,用递推最小二乘法(RLS)对被控对象进行参数辨识。仿真实验证明,该模型与被控对象模型相吻合、过程简单、效果良好、易于实现编程。基于此对控制参数进行了优化,改善了系统的动态品质。具有实用价值。     

核电站水压试验泵柴油发电机组鉴定方法研究

介绍了水压试验泵柴油发电机组(LLS柴油发电机组)的功能、系统组成及性能要求,通过对相关标准进行分析、比较并结合核电站实际运行要求,明确了LLS柴油发电机组鉴定应包括的试验项目、试验方法、试验要求以及试验合格标准。LLS柴油发电机组鉴定方法研究有利于对核电站设备质量的控制和管理,对其它有抗震要求设备的鉴定也有一定的参考意义。     

POA-DPSA混合算法在短期优化调度中的应用

根据逐步优化算法和逐次逼近优化算法的思想，提出了POA-DPSA混合算法，建立了清江梯级水电站短期发电效益最大模型，并利用逐步优化逐次逼近混合算法进行模型求解，在给定总用水量和各时段电价，满足各种约束条件下使总的发电效益最大，取得了较好的优化效果。