Capacitor installations are vulnerable during earthquake. The seismic behavior of 35 kV capacitor installation was studied, as well as the comparison between two methods proposed by the ‘Code for Design of Seismic of Electrical Installations’ and the ‘IEEE Std 693—2005’ for seismic design. The 35 kV capacitor installation was modeled and its seismic response was analyzed using the finite element software ANSYS. The dynamic characteristics was investigated by inputting different waves respectively, such as five amplitude modulation resonance sine waves, Elcentro earthquake wave, Landers earthquake wave and artificial earthquake wave. The result shows that the capacitor installation can meet require of seismic behavior through adding two porcelain bushings, which is higher than the middle seismic level and lower than the high seismic level defined in the ‘IEEE Std 693—2005’.
The traditional method for route selection is a time-consuming, troublesome and boring task. So we should consider how to make computers select the power line path. For this purpose, this paper designed a layered model, based on which a method was proposed for power line routing. Experiments were carried out using this method to choose two power line paths. The feasibility of this method was proved with the comparison of line paths picked to the existing line that won the bidding in the same region. And the comparison between this method and Dijkstra method was investigated to validate its advantage in calculation speed.
Running monitoring platform is important to the transmission equipment in smart grid in terms of overhaul management' implementation and operation management's improvement. This system has abilitiy of real-time perception, early warning, diagnostic analysis and the operation condition prediction, based on a variety of technologies includeing electronic sensor network, wide area telecommunication and information processing technology. The application and popularization of running monitoring platform are significant for smart grid improvement and transmission equipment's operation management.
Ground-source heat pump is a new air-conditioning technology with energy saving and environmental protection. Some issues on the applicability of ground-source heat pump were investigated, such as the techno-economic condition, building load condition and capacity configuration, for its popularization and application in substations. This study puts forward some suggestions on the applicability of ground-source heat pump in terms of the upper limit of initial investment, the lower limit of energy efficiency ratio (EER), the upper limit of investment recovery period, the lower limit of building load and the collocation mode of heat pump unit.
The connection of distributed generation (DG) will change distribution network form single-source radial network to multi-source network, as well as the distribution of power flow leading to unreliability of the relay protection. According to the impact of DG connection on the relay protection of distribution network, a method was proposed for fault isolation and service restoration using directional pilot protection and over-current protection. This method can solve DG connection problems and improve the efficiency of DG utilization. Power system simulation software PSCAD/EMTDC was used for the simulation of 10 kV distribution network, whose results proved the method's effectiveness and correctness.
In order to transfer large capacity hydropower from west of Sichuan province to outside, State Power Grid Corporation plans to establish three-DC and two-AC UHV transmission line. The transmission capability from the west to the east and the interaction between AC and DC transmission system are analyzed, focusing on the study of how to using the advantages of UHVDC transmission system and the grid characteristics to improve the grid reliability of Sichuan province.
In order to achieve a simple structure and definite transit route of load, either weld with plate or bolts connection should be provided at the section with slope change on the main member of steel tubular tower. Taking the SJ276 tower for 1 000 kV AC double circuits transmission line from HuaiNan to ShangHai, weld with plate and bolts connection are respectively applied. The economical efficiency and security of applying two connections in the SJ276 tower are analyzed. The results indicate that the tower is safe entough under two connections, while the weight of tower can be reduced about 2% by applying bolts connection.
Angle steel and steel tube have their respective advantages and The cross arm's extension length and stress of UHV tower are much more than those of ordinary tower, and the main-leg and diagonal member's stress and effective length of the cross arm are both less than those of tower, leading to the difference in UHV cross arm selection in China. In the case of the strain steel tubular tower in Anhui-to-East two-circuit UHV lines built on one tower, the selection of angle steel or steel tube was investigated for main-leg and diagonal member of the cross arm. This paper presents a selection method for cross arm, which can provids references for engineering design.
The impact of elevation on lightning current parameters could not be analyzed in Yunnan Province due to the lack of elevation data in thunderbolt information obtained by lightning location system. In this paper, lightning location system and Global Mapper analysis software were used to investigate the relationship between lightning current parameters and elevation. Based on the elevation data in thunderbolt place obtained by advanced spaceborne thermal emission and reflection global digital elevation model(ASTER GDEM), the relations between elevation and lightning peak current, return stroke times, cloud-to-ground flash density or positive lightning proportion in thunderbolt were analyzed. The research presents a law of lighting parameters and elevation, which could provide references for power grid design and lightning protection alteration. Location System, Global Mapper analysis software and the ASTER GDEM, which provides the foundation of the power grid design and the measures of lightning protections.
Based on the status of 10 kV distribution network fault, this paper proposed a feeder automation construction idea with outage management and control in terms of knowing-power outage, decreasing-power outage and avoiding-power outage. The self-healing feeder automation model of the main lines, branch lines and user lines were investigated, which provided reference for choosing the mode of feeder automation. The engineering practice proves that outage failure management and control is necessary to feeder automation construction.
A diesel generator was added to the auxiliary power system as emergency power in order to prevent the bad influence of extremely heavy weather, which may cause the blackout accident of station power supply and emergency power supply in converter station. An optimization scheme was proposed for auxiliary power layout that arranged a 10 kV HV switch cabinet beside the low-end valve power center (PC). This scheme can form the power center of the whole converter station and save a large number of HV cables.
A design scheme was proposed for a small-scale aerial relay station directly located on the tower for ultra-long span transmissions in UHV power lines. This study analyzed the design scheme's feasibility, composition, simulation model, field test results, simulation results and economic practicality, which could provide a new idea for ultra-long optical communication in UHV power systems.
In this paper, the status of localization situation and quality for four major pipes in ultra-supercritical units were briefly discussed, and the economic benefit of localization for four major pipes also was studied. The result shows that there are many domestic manufacturers having the ability to produce four major pipes, which have met the related standards and put into use in several power plants.
This paper proposed the a integrated technology of energy saving and environment protection (ESEP) and a process route of efficient flue gas treatment technology, according to the main future development layout and available energy saving and ESEP technology for ultra supercritical coal-fired units in China. The efficiency of ultra supercritical unit and the development trend of efficient flue gas treatment technology were analyzed for the future ten years in China. The result shows that the integrated technology of ESEP and the process route of efficient flue gas treatment technology should be different according to the characteristics of different regions in china.
Due to unreasonable arrangement of flue behind induced draft fan (IDF), there are some problems in terms of a flow resistance increase and a desulfurization efficiency decrease. According to the phenomenon of compact arrangement of boiler tail section and flow breakdown of conflux flue behind IDF in a power plant of Sinkiang, the conflux flue behind IDF was numerically simulated by computational fluid dynamics (CFD), and some splitters were used for flow field optimization with good effect.
It should be considered in natural draft counter-flow cooling tower (NDCCT) design that the natural wind may reduce the efficiency of cooling tower. In this paper, pressure flume model has been used to investigate the influence of natural wind on the resistance coefficient at the air inlet of NDCCT. Laboratory experimental results show that the resistance coefficient at the air inlet increases with an increase in the natural wind speed. This study presents an estimation formula of resistance coefficient at the air inlet for variable natural wind speeds, which provides references for NDCCT design.
The generators of 1 036 MW ultra-supercritical unit in Haimen power plant use the single-ring type sealing oil system. A method was proposed for hydrogen leakage determination without collapsing sealing oil bearings, based on the clearance changes or damage degree of seal tile by measuring the oil leakage weight of seal tile, under the running condition of loading, 3 000 r/min or turning. This simple and feasible method can be used as a reference for the hydrogen leakage determination of other similar units.
There are many galleries with different functions and design requirements in nuclear power plant (NPP), which are set for linking the pipes and cables between the workshops and providing the accesses for personnel, but there is not specific gallery design code for the 3rd Generation NPP in China at present. Combined with the gallery design in Taishan Europe pressure-water reactor (EPR) NPP, the characteristic, basic functions and main design contents of galleries were described in detail, and the method and design idea of the gallery were proposed for EPR NPP. This paper suggests some optimization approaches for gallery engineering design, which will provide references for the follow-up NPP and promote the establishment of design code.
Compared with the wet cooling tower in same capacity units, the indirect dry cooling tower has larger structure size and more sensitive to wind pressure, which is the primary load for tower. The external surface roughness of tower cylinder was increased by strengthening ribs, with decreases in the distribution coefficient of wind pressure and the internal forces of tower cylinder, diagonal column and circular foundation. Combined with practical work, distribution coefficient of wind pressure, forced character and local stability of indirect dry cooling tower with ribs were calculated and analyzed compared with those of tower without ribs, which can provide theoretical basis for structure design of indirect dry cooling tower.
Circulating water pump (CWP) is the main power consumption equipment and the cold end optimization is one of the important energy-saving items in fossil fuel power plants. The optimized allocation of CWP with unequal capacity in design stage can obtain a more flexible flow combination in order to meet the required cooling water of unit. By comparing the present energy-saving methods of CWP with the selection of CWP with unequal capacity, the scheme presented in this paper can achieve the energy-saving regulation of CWP, which will bring about a striking energy-saving effect by applying to 2×1 000 MW units.
Based on the electrical differences between gas turbine generation and coal-fired power generation, this paper analyzed the protection effectiveness traditionally used in coal-fired unit for gas turbine generator in variable frequency starting process. Some special protection configurations were studied, such as overcurrent protection, stator ground fault protection, main transformer differential protection, generator low-frequency protection and stator low voltage protection, during the variable frequency starting progress of gas turbine generator. A typical protection configuration was proposed for gas turbine generator units (≥300 MW), according to the comparison of protection configuration between gas turbine generation and coal-fired generation under the mode of grid-connected operation.
There are a lot of crimping processes for strain clamps in the extension project of the 1 000 kV Nanyang substation. The crimping is an important hidden project and critical quality control point, the quality of which will directly affect the schedule and quality of busbar installation project. The 1 000 kV strain clamps have the characteristics of bigger external diameter, longer crimping length, more crimping numbers, and more centralized crimping time, so conventional crimping methods are difficult to meet the requirements of efficiency and quality. This paper proposed a safe and reliable mechanization device for flexible busbar crimping, which could remarkably improve the crimping efficiency, and avoid the common quality defects of strain clamps bending.
Tests and analysis with the finite element method (FEM) have been used to study the behavior of Q460 welding neck flanges joints under axial compressive load. Flange modes of FP2121 and FP2727 were selected and the flange joints were subjected to axial compressive loads. The ultimate bearing capacity of the joints considering large elastoplastical deformation were analyzed by using the finite solid element. The result shows that the failure mode of the joints is the local buckling of the pipes, while the strength of the flanges is more than enough. The two circular fillet welds at neck and bottom have effects on the load transmission. The ratio of load transmission due to neck and bottom fillet weld is 3∶1, which is consistent to the testing results.
The macro-inspection and microstructure analysis of cracks for welded joints were investigated, according to the leakage of T23 Steel tube welded joints in a 1 000 MW ultra supercritical tower-type boiler. The result shows that the water-wall tube weld cracks are caused by residual stress and structural binding stress of welded joints.
The extension project of 1 000 kV UHV Jingmen station is an important part of the first extension pilot project of UHV AC transmission. Construction management of this project has outstanding characteristics and difficulties. The manage department has performed main responsibility and leading at construction site, and taken a series of management and control measures in terms of safety, quality, technology and progress based on the project's characteristics and difficulties. This project's construction management and control strategy has achieved the construction goal.
According to the valve pulse loss phenomenon during debugging stage of Gaoling back-to-back HVDC system, the influence of valve pulse loss on the HVDC system operation and the protection coordination were investigated. The fault type of pulse loss has been dissertated, and the simulation results of PSCAD/EMTDC were demonstrated to verify the validity of the fault analysis. The research results provide theoretical guidance and help for the operation and maintenance of HVDC converter station on site.
This paper introduced the construction scheme of decomposition assembly by grounding hold-pole for the LV-shaped iron tower in 750 kV Xining-Riyueshan-Wulan electric transmission line engineering. This construction scheme's process, machine selection and operation point were investigated, as well as its economic and social benefits in engineering applications.
This paper presented an efficient method for cleaning the pollution in stator short circuit accident of 1 000 MW turbine generator, which used large flow airs to blow stator core backside, core axial ducts, and generator base ducts. The blowing system of stator cooling ducts was introduced in details including the points for attention in every stage and the test method of blowing effect, which could provide reference for the similar accident treatment.
