Small Hydropower Stations Research Articles

小水力発電への可変速システムの適用

小水力発電への可変速システムの適用

Discussion on Establishing Retirement Mechanism of Rural Small Hydropower Station in China

Practices of dam and hydropower station retirement in America and China are summarized in this paper. The establishment of rural hydropower station retirement is the necessary part of the life-cycle of water power resource management, and it is also an effective way to promote the transformation of rural hydropower industry, and a reflection of new requirement by social and economic development. The analysis shows that the establishment of hydropower station retirement mechanism should be given equal importance as dam retirement,owing to that it provides basic support from law, society and previous work. Guided by the new concept and stakeholder analysis, the retirement assessment criterion and compensation standard are necessary for scientific assessment and decision on retirement of hydropower stations. The establishment of rural small hydropower retirement mechanism in China would advance the sector management of rural hydropower.

A methodology for optimization of the complementarity between small-hydropower plants and solar PV systems

Key global energy, environmental and sustainability targets are closely related to the development of Renewable Energy Sources (RES). This includes reduction of Greenhouse Gas emissions and safe energy provision in a sustainable manner. The integration of RES in the energy mix needs to overcome the technical challenges that are related to grid's operation. Therefore, there is an increasing need to explore approaches where different RES will operate under a synergetic approach. A straightforward way to achieve that is by optimizing the complementarity among RES systems both over time and spatially. The present article developed a methodology that examines the degree of time complementarity between small hydropower stations (SHPS) and adjacent solar PV systems (SPVS). The methodology builds on an optimization algorithm that associates hydrological with solar irradiation information. In particularly, the algorithm examines possible alterations on the PV system installation (azimuth, tilt) that increase the complementarity, with minor compromises in the total solar energy output. The methodology has been tested in a case study and the outcome indicated that a compromise of 10% in the solar energy output (90% threshold) may result in a significant increase of the complementarity (66.4%).

Smooth Evacuation of Power in Grid Connected Small Hydro Power Stations by Application of SVCs

This paper explores some of the practical limitations encountered by small hydro power (SHP) units while evaluating various possibilities so as to maintain continuous generation by these units while ensuring smooth evacuation of every unit of real power generated by such units to the neighboring grid in a grid connected power system scenario. The proposed simulation has been tested under some worst system conditions and case studies conducted on the IEEE 30-bus test system by way of connecting the SHP units to the most critical system bus of the test system with static VAR compensator (SVC) control at the local bus. The test results have been validated with the support of power flow tools on a Matlab based Matpower platform. It is observed that the results obtained through application of SVCs are far more promising than those of the results obtained from OLTC transformer control mechanism only.

含多小水电的配电网电压分析与控制策略研究

小水电以分布式发电的形式在配电网并网发电，改变了传统的配电网的运行方式，引起配电网枯水期电压偏低、丰水期电压偏高、线路末端电压随季节波动较大等问题。本文对含小水电配电网电压问题分析得出，小水电的接入使配电网从无源网络变为有源网络，由原来的单向潮流变为双向潮流，当丰水期小水电发电量较大时潮流反送到主网中，引起配电网电压升高。同时提出了通过改变网络结构并结合并联补偿的方法对电压进行控制，改善配电网的电压质量。 Traditional operation mode of distribution network was altered with the integration of small hy-dropower in it, which causes the problem that the voltage of distribution network drops in dry season, increases in wet season, and the voltage fluctuates greatly with seasons especially at the end of the line. Analysis on voltage problem in distribution network in this paper draws the conclusion that in wet season, the voltage rises since the power flow contrary sends to the main network when the small hydropower station’s generating capacity increases. This paper also presents a method of voltage control by changing the distribution network structure, combining the method of installing parallel compensating devises, which can improve the quality of voltage in distribution network.

Smooth Evacuation of Power in Grid Connected Small Hydro Power Stations by Application of SVCs

Smooth Evacuation of Power in Grid Connected Small Hydro Power Stations by Application of SVCs

Application of Fuzzy Recognition Model for the Diversion Structures Safety Evaluation at Small Hydropower Stations

In this passage is about the safety evaluation on the conveyance structure of small hydroelectric power station. Applying Binary comparative indicators to determine the weights and fuzzy recognition model on the conveyance structure of small hydroelectric power station’s assessment. Compared other models with fuzzy recognition model which will be explained in detail in the next section on a specific small hydropower station. The results show that the fuzzy recognition model is feasible and effective on safety evaluation on the conveyance structure of the hydroelectric power station.

Power Control of Microgrid with Rich Small Hydropower Stations

In China, some remote areas with rich small hydropower stations suffer from a tradeoff between water surplus and off-limit voltage in the grid during wet seasons. The microgrid of new energy sources provides a new way of solving this problem. Under the background of the microgrid proposed in somewhere of Jiangxi Province, this paper firstly carries out simplified model on the actual system. Output models of PV and small hydropower stations are established. Then with Minimizing transmission losses of microgrid system and the amount of all small hydropower abandoned waters as the optimization objective, and considering the output constraints of each micro power source, power balance constraints and voltage constraints. A micro-power output optimization model is established and then solved by improved particle swarm optimization algorithm. By comparing the micro-power output and system line loss before and after the optimization, it verifies that the proposed power control method can prevent the off-limit voltage effectively and reduce transmission losses of the system.

The Application of Safety Membranes in Hydropower Plant

Safety membrane is a good mechanical device that can be applied in middle and small hydropower stations instead of a surge tank. This present study deals with the determination of three most important parameters of safety membrane, rupture pressure, diameter, and number. The mathematical model of transient process is established by introducing the method of characteristic, which is used for the simulation of the rupture behavior of safety membrane. Then the model is applied to a specific hydropower station that only can employ safety membrane as the regulating measurement, and it shows good performance. The achievements of the study can serve as a reference for similar projects.

Study on Regulating Valve Settings for Small and Medium Cascade Hydropower Stations

For some small and medium cascade hydropower stations, they need to set regulating valves to regulate the discharged flow and ensure downstream water. this paper use an example of a cascade hydropower station to explore some issues related to regulating valve settings through some aspects like selecting the diameter of regulating valve, the impact on the regulation and assurance measures of hydropower stations with regulating valves and so on.Conclusions show that the water hammer pressure is the smallest when the diameter of the regulating valve is 0.7m,and the use of regulating valves can relieve the rise of water hammer pressure.These conclusions have referential significance on small and medium cascade hydropower stations.

Potential and Analysis of Grid Integrated Renewables in Latvia

In the last ten years a 10% increase in the energy consumption in Latvia has been observed; this means increasing import of electricity and energy resources, since the volumes of electricity produced in Latvia are insufficient for covering the electricity demand. The energy demand, being ever increasing, along with the limited fossil fuel reserves as well as environmental pollution and global climate changes, has aroused an active interest in renewable energy resources. In the world, a tendency is developing fast – that of the necessity to replace, step-by-step, the traditionally employed energy carriers by those of higher quality, with inclusion of renewable energy resources - biomass, hydro, wind and solar energy. This would undeniably lead to the cost reduction for the RES use technologies, which, in turn, would mean increase competitiveness and wider utilization. A part of electricity, about 70% of the total electricity consumption in Latvia, is generated by hydro plants and combined heat and power plants, an insignificant part is produced by small hydro power stations and wind generators, and the rest is imported from abroad.

Short-Term Power Generation Energy Forecasting Model for Small Hydropower Stations Using GA-SVM

Accurate and reliable power generation energy forecasting of small hydropower (SHP) is essential for hydropower management and scheduling. Due to nonperson supervision for a long time, there are not enough historical power generation records, so the forecasting model is difficult to be developed. In this paper, the support vector machine (SVM) is chosen as a method for short-term power generation energy prediction because it shows many unique advantages in solving small sample, nonlinear, and high dimensional pattern recognition. In order to identify appropriate parameters of the SVM prediction model, the genetic algorithm (GA) is performed. The GA-SVM prediction model is tested using the short-term observations of power generation energy in the Yunlong County and Maguan County in Yunnan province. Through the comparison of its performance with those of the ARMA model, it is demonstrated that GA-SVM model is a very potential candidate for the prediction of short-term power generation energy of SHP.

A Comprehensive Model for Monthly Prediction of Energy Output of Run-of-River Small Hydropower Station in Electricity Market Environment

According to generated output characteristics of run-of-river hydropower station in electricity market environment,a comprehensive model for monthly prediction of energy output based on Partial Least-Square (PLS) and improved Grey Model (GM) is established.The PLS model takes full advantage of the relationship between monthly energy output and its correlation affecting factors,and then using improved grey model to forecast its main factors to get final predictive results further.The comprehensive model not only can effectively use the limited sample,but also can weaken the random impact.The actual prediction results shows that the effect is better than common methods.

The Application of Earned Value Management in Small and Medium-Sized Hydropower Stations Project

Earned value management is a prerequisite for the wide range of applications in the practice of project management at home and abroad. In this paper, As to the quality of the target cost and schedule goal, To the project cost and schedule performance evaluation, On the basis of reading the relevant literature and researching at home and abroad. Using theory and method, which cost and schedule performance evaluation of earned value management as the research object. Application of project management software, It is greatly meaningful to applying earn value management model to small and medium-sized hydropower stations project.

Simulation Design on the Network Monitoring System of Small and Medium-Scale Hydropower Stations

As the hydro-engineering projects are often featured with long construction period, great investment and many cooperative departments; moreover, they are usually seriously affected by natural resources, topography, geology and hydro-meteorological condition; it seems quite necessary to design a set of network monitoring system to store, simulate and analyze the historical hydrologic data and planning data. This paper first briefly analyzes the simulation design status of current network monitoring system for hydropower stations, then explores or analyzes the structure of network monitoring system for small and medium-scale hydropower stations and the detailed design programs, and finally it describes its application prospects so as to offer references for others.

The Application of Monte Carlo Simulation in Present Earning Value Method — Case Study of a Medium Hydropower Station

Processing the parameters overly simplistic will leave space for overestimating or underestimating artificially when we assess the assets of medium and small hydropower stations using present earning value method. And absolute assumptions often affect the adequacy of the assessment results, also the persuasive and credibility. Monte Carlo simulation can determine the wave of parameters in present earning value method, so as to improve the persuasion and credibility of assessment results and reduce the personnel control.

Case Study on the OOPP Theory Using AHP Method-Application in Improvement of Long Feng Hydropower

It is essential for the small and medium-sized hydropower stations to choose a best project during the technological innovation and standardize management process. Thus, it can lay a solid foundation for the overall efficiency of enterprises in the future. Long Feng station is in the transition period after the acquisition and alteration, by data analysis, there are some questions: (1) management system is chaotic; (2) the overall quality is not high; (3) cost of power generation is high, but economic efficiency is low; (4) ecological environment pollution is serious; (5) living conditions of residents is threatened. To solve the above problems, this paper applies the OOPP theory as a guide and the Analytic Hierarchy Process as a tool in the alternative project analysis, combines the method of qualitative and quantitative, and finally can provide a valid scientific basis for decision to choose the best subproject.

Research on DSP-Based Automatic Excitation Regulator in Small Rural Hydropower Station

Excitation regulator has played an important role to ensure that generator run safely and stably. However, in some remote areas, the rural small generator excitation control system is very backward, and it has hindered the development of Chinese agriculture and the pace of new countryside construction. This paper introduced a kind of structure and basic principle of DSP-based automatic excitation regulator, which was applied to rural small generator. We chose TMS320LF2407A chip as the core of regulator control system; the regulator adjusted PWM based on PID control strategy to control the exciting current. The theoretical analysis showed that the regulator had the characteristics of simplicity and reliability, well dynamic and static characteristics, and it could also adjust its own state quickly. The result was applicable to small rural hydropower station.

Detection of Harmonic and Inter-harmonic Caused by Synchronization of Small Hydropower Station

Detection of Harmonic and Inter-harmonic Caused by Synchronization of Small Hydropower Station

Research on Main Problems and their Countermeasures on Chinese Small Hydropower Development

The constructions of small hydropower stations play an important role in improving local energy structure, development of corporations, agricultural and environmental melioration, and improving living standard of local people. Thus, studying status at small hydropower stations of China and existed problems in their development has a practical significance. With investigation data, the paper comprehensively analyzed running status of the stations, equipment aging in their development, lower utilized water resources, backward management, and disordered exploitation, etc. Therefore, the authors put forward the stations need to be technically reformed, perfecting management, professional training and so on, so that utilization efficiency on water resources could be continually improved.