The doubly-fed wind power generator control system consists of multiple PI controllers, each of which directly affects the dynamic characteristics of the wind power system. In this paper, a particle swarm optimization...
The doubly-fed wind power generator control system consists of multiple PI controllers, each of which directly affects the dynamic characteristics of the wind power system. In this paper, a particle swarm optimization algorithm with improved inertia weight is used to simulate and analyze the control system optimized by algorithm. It is found that the improved characteristic curve has the advantages of small overshoot, fast adjustment speed and short adjustment time. The effectiveness and superiority of the particle swarm optimization algorithm for PI controller parameters optimization.
In order to explore the best air distribution scheme, and set up a air distribution test bench, which is according to the similarity principle, in this paper, a 350MW supercritical boiler of a power plant is taken as ...
In order to explore the best air distribution scheme, and set up a air distribution test bench, which is according to the similarity principle, in this paper, a 350MW supercritical boiler of a power plant is taken as the research object. This test the selection of fan power and the design of bellows and air duct size is according to the similarity principle. According to the test procedure, the resistance coefficient and flow rate of the damper are measured when the single and each damper is changed. It is found that the drag coefficient and flow rate are greatly affected by the opening of the damper. When the opening of the damper changes from 15 to 30 degree, they both change dramatically. When the opening of the damper is greater than 30 degree, the change of them tends to be stable. At the same time, different locations of damper will interact with each other. The resistance coefficient curve is not only plays a guiding role in the manual control of the old equipment, but also plays a vital role in the programming of the modern automatic control of the damper. At the same time, the flow distribution law plays a guiding role in the design of the air distribution control system. The resistance coefficient curve and the flow distribution curve obtained in this paper can play a guiding role in the test design and boiler operation regulation of power plant.
Prelithiation technology can improve the service life of batteries, but whether it will affect the safety of batteries has not been studied. In this paper, the temperature differences between LiFePO4/C batteries with ...
Prelithiation technology can improve the service life of batteries, but whether it will affect the safety of batteries has not been studied. In this paper, the temperature differences between LiFePO4/C batteries with prelithiation technology and conventional LiFePO4/C batteries in overcharge test are analysed, the shell deformation values of these two types of batteries are compared, and the influence of battery capacity retention rate on overcharge safety of batteries is discussed. The analysis shows that there is no obvious difference in overcharge safety between two types of batteries, and batteries with prelithiation technology are similar to conventional batteries in terms of shell deformation value, the highest temperature of shell and the temperature fluctuation of flue gas escaping from pressure relief valve.
Abstract . This article has studies on the generation investment decision in the background of global energy interconnection. Generation investment decision model considering the multiagent benefit is proposed. Under ...
Abstract . This article has studies on the generation investment decision in the background of global energy interconnection. Generation investment decision model considering the multiagent benefit is proposed. Under the back-ground of global energy Interconnection, generation investors in different clean energy base not only compete with other investors, but also facing being chosen by the power of the central area, therefor, constructing generation investment decision model considering multiagent benefit can be close to meet the interests demands. Using game theory, the complete information game model is adopted to solve the strategies of different subjects in equilibrium state.
The LiFePOVC battery has been widely used in many fields, and its safety problems are gradually attracting widespread concern. In this paper, two kinds of LiFePO4/C batteries with 25 Ah and 200 Ah were taken as resear...
The LiFePOVC battery has been widely used in many fields, and its safety problems are gradually attracting widespread concern. In this paper, two kinds of LiFePO4/C batteries with 25 Ah and 200 Ah were taken as research objects. The thermal runaway phenomena of two batteries were analyzed, and the difference of thermal runaway phenomena between two batteries were compared. The results show that the safety valve of the 200 Ah battery ruptures earlier and the thermal runaway occurs earlier under the same overcharge rate. The work provides a reference for the protection design of LiFePO4/C batteries.
Under the background of the global energy Internet, the investment planning of transmission corridor from XinJiang to Germany is studied in this article, which passes through four countries: Kazakhstan, Russia, Belaru...
Under the background of the global energy Internet, the investment planning of transmission corridor from XinJiang to Germany is studied in this article, which passes through four countries: Kazakhstan, Russia, Belarus and Poland. Taking the specific situation of different countries into account, including the length of transmission line, unit construction cost, completion time, transmission price, state tariff, inflation rate and so on, this paper constructed a power transmission investment model. Finally, the dynamic programming method is used to simulate the example, and the optimal strategies under different objective functions are obtained.
Prelithiation technology has greatly improved the service life of LiFePO4/C battery, but its influence on the combustibility of the battery is still unclear. In this paper, the combustibility of the key components (po...
Prelithiation technology has greatly improved the service life of LiFePO4/C battery, but its influence on the combustibility of the battery is still unclear. In this paper, the combustibility of the key components (positive electrode, negative electrode and separator) of LiFePO4/C battery with prelithiation technology and conventional LiFePO4/C battery are compared, and the differences in combustion parameters(effective combustion heat, total heat release, heat release rate) and smoke parameters(total smoke production, CO yield, CO2 yield, and specific extinction area) between the two types of batteries are analyzed. The results show that the combustibility of the two types of batteries is basically similar, and there is no significant difference. With the decrease of the capacity retention rate, the combustibility and smoke generation of the battery show a downward trend.
In this paper, thermal runaway test of lithium iron phosphate battery (LiFePO4/C) under overcharge condition was carried out. The temperature and its rise rate of three types of LiFePO4/C batteries (25 Ah, 60 Ah and 2...
In this paper, thermal runaway test of lithium iron phosphate battery (LiFePO4/C) under overcharge condition was carried out. The temperature and its rise rate of three types of LiFePO4/C batteries (25 Ah, 60 Ah and 200 Ah) in the process of thermal runaway were compared and analyzed. The research shows that under the condition of 1C-rate overcharge, the starting temperature of the LiFePO4/C battery thermal runaway is about 116 °C - 131 °C, and its temperature rise rate of thermal runaway is about 3.01 °C/s - 5.82 °C/s. The highest temperature reached by thermal runaway has nothing to do with the battery capacity.
With the development of science and technology, the hardware and software design of transformer intelligent measurement and control terminal is very important. Based on the hardware and software appization of internet...
With the development of science and technology, the hardware and software design of transformer intelligent measurement and control terminal is very important. Based on the hardware and software appization of internet of things, the design scheme of hardware and software structure is given. Supported by high-performance operating system, the terminal device can be upgraded flexibly through APP application software. The intelligent terminal pair can realize full data collection, full control and full fusion, and real-time exchange of key operation data with the power distribution master station. The intelligent terminal can support 5G communication and realize full compatibility of communication conditions downward.
Swirling waterjet, using swirling and cutting capacity of high velocity waterjet beam, is a kind of technology widely applied in foundation processing, tunnelling, coalbed methane mining, and etc. It is extremely comp...
Swirling waterjet, using swirling and cutting capacity of high velocity waterjet beam, is a kind of technology widely applied in foundation processing, tunnelling, coalbed methane mining, and etc. It is extremely complicated because the existence of high velocity gradient and swirling, nevertheless, knowing unsteady interior flow characteristic and flow pattern which tremendously affects cutting capacity of waterjet is what we concern about. In this article, computational fluid dynamics is utilized to study flow characteristics of swirling turbulent waterjet, convergent nozzle structure with swirling is chosen as prototype and investigational region is selected as waterjet flow could be fully developed, structured mesh and grid number independent is obtained, Reynolds stress turbulence model is employed and standard wall functions is chosen as the near-wall treatment, pressure boundary conditions are applied on inlet and outlet boundaries, the SIMPLE algorithm is employed to couple the pressure and velocity, and time step size and number is selected reasonably. According to numerical simulation results, statistical analysis method, comparative analysis method and dimensionless analysis method is used to analyse central line velocity attenuation, velocity profile of different axial and radial position, flow pattern and vorticity characteristics, influence of different swirling velocity is also investigated, cutting capacity and influence factor of high pressure swirling water jet is evaluated. It is valuable for application of CFD in swirling waterjet field and helpful for understanding interior filed of swirling waterjet flow, meanwhile, this work could also provide reference for further investigation and application about swirling waterjet.
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