Papers by Keyword: Converter

Abstract: Low energy positron beams have become a valuable tool for depth dependent characterization of defects and micro- and mesoscale porosities, as well as for fundamental positron and positronium interactions. Some of the recent developments in the generation of secondary positron beams using particle accelerators are presented and the underlying physics and technologies are discussed.

Abstract: A 300-metric ton converter in a steel plant in China was studied. The influence of factors such as slag composition and temperature in the smelting process on the dephosphorization effect was statistically analyzed. The dephosphorization ability of slag increased firstly and then decreased with the increase of temperature, basicity and FeO content. Low-temperature, high-basicity and high-oxidizing slag are thermodynamically beneficial to promote the dephosphorization reaction, but the basicity is higher than 4.0, and the temperature is higher than 1640 °C are not conducive to the slag to obtain better fluidity. At the same time, too high FeO content will increase the activity coefficient of P₂O₅, thereby increasing its activity, which is not conducive to the progress of the dephosphorization reaction. As the end point content of carbon decreases, the oxygen content increases and the phosphorus content decreases. A very low carbon content is not conducive to metal yield and temperature control.

Abstract: Power electronic devices are the basis of power converters, and excellent device performance improves that of power converters directly. In this paper we take SiC MOSFET CAS120M12BM2 (1200V/ 120A) and Si IGBT FF150R12KE3G (1200V/150A) as examples, which have the same voltage rating, to apply to the converters of urban rail vehicles, whose switching frequency, power density and efficiency are analyzed and contrasted. The results show that the switching frequency of the SiC MOSFET converter can be increased to 50kHz, at the same time its power density and efficiency are significantly higher than that of the Si IGBT converter.

Abstract: Through thermal simulation experiment and SEM analysis, limestone dissolution in a steelmaking slag was studied. The results showed that the dissolution rate of limestone is 5.4 times greater than lime under the same conditions in slag, the dissolution rate of limestone in slag increases rapidly with the increase of stirring gas flux. The rapid dissolution of limestone in the slag can be explained on two sides. Limestone decomposition and dissolution happens simultaneously, the newly generated lime participates in slagging in its highest activity. On the other hand, CO₂ from limestone decomposition not only strengthen the mixing strength of the molten pool, but also helps to remove the high melting point 2CaO·SiO₂ product.

Abstract: The maximum output power of a photovoltaic (PV) system with a DC-DC converter depends mainly on the solar irradiance (G) and the temperature (T). Therefore, a maximum power point tracking (MPPT) mechanism is required to improve the overall system. The conventional MPPT approaches such as the perturbation and observation (P&O) technique have difficulty in finding true maximum power point. Thus various intelligent MPPT systems such as fuzzy logic controllers (FLC) are recently introduced. In FLC based MPPT, selecting the type of the membership function (MF) and the number of the fuzzy sets (FS) is critical for better performance. Thus, in this paper various adaptive neuro fuzzy inference system (ANFIS) is utilized to automatically tune the FLC membership functions instead of adopting the trial and error method. To find suitable MF for FLC, ANFIS is developed in MATLAB/Simulink and the effect of different types MF investigated. Simulation result shows that the FLC with triangular MF and seven FS give the best result. The evaluation indices used in this study includes the maximum extracted energy, minimum standard deviation of the error, and minimum mean square error.

Abstract: In this paper, a memristive neural network was applied to fault diagnosis of wind turbine's converter. A model of memristive neural network was built in order to diagnose and analyze of the failure information by MATLAB Simulink. Experimental results show that the proposed method can achieve better results and has certain significance for the application of memristors widely used in the near future.

Abstract: Distributed generation system (DGs) is considered to be an advanced configuration of distributed generation through the effective organization of renewable energy power sources, loads and energy storage devices, which can operate either isolation or connected with grid. This paper studied the control of DGs which is constructed with DFIG (Double Fed Induction Generator) based Wind Farm, PV (Photovoltaic) generation farm and Storage Batteries. The paper studied the simulation model of the DGs and the control strategy.

Abstract: A single-stage PFC converter was introduced in this paper, then the converter EMI filters, converters inductors, high-frequency transformers and power components were designed and chosen, proven to good effect.

Abstract: For solar power generation system based on single-chip microcomputer control application in the unit worker bath problem, this paper introduces the working principle of solar power, including solar power system of power and solar power, solar power conversion Z - source converter, discusses the hardware of solar power generation system, solar power generation of software, including in software discussed, mainly discusses the A/D interrupt of solar power, solar power generation Timer interrupt the functionality of the M PPT and solar power, solar power system for single chip microcomputer control application in the unit worker bath, provides the technical support.

Abstract: Converter smelting medium-low carbon ferrochrome replaces electronic by oxygen and reduces production energy consumption greatly. Medium-low carbon ferrochrome end sulfur content analysis is necessary to determine the product quality. Now we still use the product sampling, laboratory analysis to determine end sulfur content, which can not realize online monitoring. According to this status, a PLSBP prediction model of end sulfur content has been established based on particle swarm algorithm, which combined partial least squares method and BP neural network. At the same time, A feedback compensation model has been established by dichotomy, which avoided the model failure caused by raw material quality change. The simulation results showed that the hit rate of prediction model was 96.67% within the absolute error, 90% within relative error. High precision was achieved, which provided an important theoretical basis to improve product quality and optimize the production process.