Xue B.,Tongliang Power Supply Ltd Liability Company |
Cheng C.,Yalong River Hydropower Development Company |
Ou S.,Tongliang Power Supply Ltd Liability Company |
Liu A.,Tongliang Power Supply Ltd Liability Company |
Wang S.,Tongliang Power Supply Ltd Liability Company
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2017
There are two problems in conventional linear regression model for forecasting monthly electricity sales that affect precision: the model ignores the fact that there are no heating measures and cooling measures in comfortable temperature range; the model also ignores the influence of random factors on monthly electricity sales because of random factors are difficult to quantify. To solve the above two problems, this paper puts forward two improvement measures: selecting low threshold temperature and high threshold temperature, and producing heating or cooling measures only when the actual temperature is below low threshold temperature or above high threshold temperature; proposing a method to quantify factors and putting the quantization value into prediction model as a factor of monthly electricity sales. The improved model can not only establish the relationship between temperature and monthly electricity sales preferably but also can account for the effect of random factors on monthly electricity sales reasonably, so the proposed measures are useful to improve precision. Making simulation analysis with actual data of Tongliang district in Chongqing, and the results show that the two kinds of improvement measures are effective. © 2017 Power System Protection and Control Press.
Li H.-B.,University of Sichuan |
Liu M.-C.,Yalong River Hydropower Development Company |
Xing W.-B.,Power China Chengdu Engineering Corporation Ltd |
Shao S.,University of Sichuan |
Zhou J.-W.,University of Sichuan
Rock Mechanics and Rock Engineering | Year: 2017
The Jinping I underground powerhouse is deeply buried and is one of the largest underground powerhouses in China. As a result of high levels of in situ stress, complex geological conditions and the effects of excavation in adjacent caverns, the surrounding rock mass has been severely deformed and broken, and excavation damaged zones (EDZs) have become major obstacles to the design of cavern excavation and support. Field investigations and monitoring data indicated that there are two main modes of failure: high tangential stress induced failure and progressive failure, which have occurred on the mountain side and the river valley side of the Jinping I underground powerhouse. These two main modes of failure were due to strong secondary principal stress forces in the sub-parallel directions and sub-vertical directions, acting on the axes of the main powerhouse on the mountain side and on the river valley side, respectively. Deformations and EDZs on the river valley side were generally larger than those found along the mountain side, and the distribution of deformations was consistent with the distribution of EDZs. The evolution of the EDZ on the river valley side has clearly been time dependent, especially along the downstream arch abutment, and the EDZ was considerably enlarged with further excavation. Additionally, the deformation of the surrounding rock mass was first initiated from the edge of the excavation area and gradually extended to deeper areas away from the opening. However, the EDZ on the mountain side was enlarged only during the first two phases of excavation. The extension of pre-existing cracks and the creation of new fractures has mainly occurred in the oldest EDZ section, and the HDZ has been visibly enlarged, whereas the EDZ has shown little change in other excavation phases. © 2017 Springer-Verlag Wien
PubMed | Sichuan University and Yalong River Hydropower Development Company
Type: Journal Article | Journal: PloS one | Year: 2016
Percocypris pingi is a near threatened cyprinid species, which has suffered a dramatic decline due to anthropogenic factors. As one response to this decline, hatchery release for P. pingi has been conducted in the lower reaches of the Yalong River since 2012. To understand the conservation status of this species and the potential impact of the release of hatchery-reared fish, we studied the genetic diversity and population structure of wild and hatchery populations of P. pingi. Two hatchery populations (Jinping [JPH] and Yaan [YAH]) and two wild populations (Muli [MLW] and Woluo [WLW]) of P. pingi were analyzed based on microsatellite markers and the mitochondrial DNA control region. The results showed that P. pingi possesses moderate levels of genetic diversity, with observed heterozygosities ranging from 0.657 to 0.770 and nucleotide diversities ranging from 0.00212 to 0.00491. Our results also suggested WLW harbors considerable proportions of genetic diversity in this species and serves as a refuge for P. pingi during anthropogenic disturbance, thus playing an important role for the conservation of P. pingi populations. Microsatellite and mitochondrial markers both indicated close genetic relationships between YAH and MLW, JPH and WLW, respectively. The results to some extent reflected the geographical provenances for original broodstocks of the two hatchery populations, which provide some practical guidance for hatchery release of P. pingi. The existence of remarkable genetic divergence distributed along limited geographical range (approximately 10 kilometers) suggests the two wild populations should be regarded at least as two distinct evolutionary significant units (ESUs) and management units (MUs). Considering reduced intra-population genetic variation in hatchery population for release and significant genetic compositions of the two hatchery populations, some appropriate breeding strategies were proposed to benefit conservation of P. pingi.
Liu B.,Changjiang Institute of Survey Planning Design and Research |
Liu B.,Wuhan University |
Liu J.,Yalong River Hydropower Development Co Ltd |
Wu H.,Wuhan University
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2013
A three-dimensional nonlinear simulation was made for analysis of a preloaded filling steel spiral case and its overload computation on the basis of an elastoplastic damage model for concrete and the contact nonlinear theory. The analysis focuses on the behavior of spiral case under water pressure increasing, including stress and reinforcement, damage range of surrounding concrete, displacement of generator pier, and deformation of stay ring. The results show that the spiral case alone almost bears all the internal water pressure and its stress increases very rapidly before the internal water pressure reaches the design preloading value. When internal pressure reaches the design value, the damage range of surrounding concrete and the stress of reinforcement become very small. If the overload coefficient exceeds 1.1, the damage range and damage degree on the surrounding concrete increase rapidly, and the deformations of generator pier and stay ring are significant. The spiral case structure still has a certain margin of safety, however, even when this coefficient reaches 1.5. Three-dimensional nonlinear algorithm can produce a simulation closer to the real case, and it should be adopted in design and study of preloaded filling spiral case structure. © right.
Zuo S.Y.,Guizhou University |
Cai H.L.,Yalong River Hydropower Development Company
Advanced Materials Research | Year: 2013
In the process of the optimization of concrete mixed proportions in the gravity-type dam of the upper reservoir in Yixing Pumped Storage Power station, potential problems of initial mixed proportions are analyzed and a set of nonlinear optimized multi-objective is drawn up. A stepwise regression analysis and duplex optimized method are used to solve optimized multi-objective model. By increasing the order of regression equation and softening the variables, objectives and constraints system, the shortcoming of linear optimization such as narrow variation span, severe formal limitations of objective and constraint function can be overcome and the flexibility of the choice for optimized objective is easily to be achieved. Combined with the traditional linear regression method, the results of optimization have been corrected further. The practical effect shows that the work achieves very good technical and economic benefits with a smaller amount of test work to reduce the project cost. © (2013) Trans Tech Publications, Switzerland.
Liu B.,Changjiang Institute of Survey Planning Design and Research |
Lai J.T.,Yalong River Hydropower Development Company
Progress in Civil, Architectural and Hydraulic Engineering - Selected Papers of the 4th International Conference on Civil, Architectural and Hydraulic Engineering, ICCAHE 2015 | Year: 2016
A three-dimensional finite element model of the water distribution ring pipe in hydropower station has been carried out, using the finite element program ANSYS and nonlinear contact theory. With different preloading water head (0.7, 0.8 and 0.9 times of minimum hydrostatic pressure), the stress of surrounding concrete of the water distributing ring pipe has been analyzed, which provide reference for the optimal selection of the preloading water head. The result shows that the surrounding concrete will not crack in the three schemes, because the design tensile strength of the surrounding concrete of the water distributing ring pipe is high (3.27 MPa). Considering the stress of surrounding concrete and the requirements of unit’s long-term stable operation comprehensively, the water distribution ring pipe’s preloading water head of this project is suggested to be 4.8 MPa, 80% of the minimum head (598.5 m). © 2016 Taylor & Francis Group, London.
Zhang L.,Yalong River Hydropower Development Company |
Zhang Y.N.,North China Electrical Power University
IOP Conference Series: Materials Science and Engineering | Year: 2015
Partial Averaged Navier Stokes (PANS) is a numerical approach developed for studying practical engineering problems (e.g. cavitating flow inside hydroturbines) with a resonance cost and accuracy. One of the advantages of PANS is that it is suitable for any filter width, leading a bridging method from traditional Reynolds Averaged Navier-Stokes (RANS) to direct numerical simulations by choosing appropriate parameters. Comparing with RANS, the PANS model will inherit many physical nature from parent RANS but further resolve more scales of motion in great details, leading to PANS superior to RANS. As an important step for PANS approach, one need to identify appropriate physical filter-width control parameters e.g. ratios of unresolved-to-total kinetic energy and dissipation. In present paper, recent studies of cavitating flow based on PANS approach are introduced with a focus on the influences of filter-width control parameters on the simulation results. © Published under licence by IOP Publishing Ltd.
Shang L.,Xi'an University of Science and Technology |
Xia Y.,Yalong River Hydropower Development Co.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2015
The existence of the series compensation capacitor results in the complex fault-travelling wave process of the series compensated lines and the difficulty of the wavefront recognition. From the angle of the traveling wave energy, this paper obtained the fault traveling wave by using the energy ratio function in a specific time window, leading to the realization of the travelling wave fault location of the series compensated lines. The influence of the series compensation capacitor on the energy ratio function was studied. The correctness of the application of the energy ratio function in the fault location of the series compensation lines was verified, and the principle of selecting the width of the time window was analyzed. For a series compensation transmission lines, the simulation model was established. With double terminal fault location method, under the condition of considering the interference, the energy ratio method was used to series compensated line fault location. The cases that the series compensation was located on the middle and on the both sides of the lines were simulated respectively. ATP/EMTP simulation results show that the method can be effectively applied in the fault location of the series compensation lines because of its superiority of high precision, simple calculation and immunity to the series compensation installation position and fault close angle. © 2015 Chinese Society for Electrical Engineering.
Yao Y.Q.,Chengdu University of Information Technology |
Wang W.B.,Yalong River Hydropower Development Company LTD
Applied Mechanics and Materials | Year: 2014
A new method to store the harmonic energy is proposed, by offering harmonic energy to DC load directly by combining the diode's one-way electric conduction theory with the first-harmonic resonance theory. Using the PSCAD/EMTDC software to simulate the project in single phase and three phases. And it turn out that the theory is feasible. © (2014) Trans Tech Publications, Switzerland.
Wang Y.,Chengdu University of Technology |
Zhang D.M.,Yalong River Hydropower development Company
Applied Mechanics and Materials | Year: 2014
1# bridge traffic engineering of LiangHeKou hydropower station is located in ganzi region in sichuan province. The altitude of main construction areas lies above the 2700m, perennial mean temperature ranges from -4.9 – 7.9°C, extreme low temperature reach -42.9°C, the temperature difference between day and night, which may adversely affect the execution of the precast concrete and cable erection. Based on the fully and deeply analyse and optimal approaches, We solved several key engineering challenges in precast arch box construction, and also provided valuable experiences for similar projects. © (2014) Trans Tech Publications, Switzerland.